Muscular Dystrophies: A heterogeneous group of inherited MYOPATHIES, characterized by wasting and weakness of the SKELETAL MUSCLE. They are categorized by the sites of MUSCLE WEAKNESS; AGE OF ONSET; and INHERITANCE PATTERNS.Muscular Dystrophy, Duchenne: An X-linked recessive muscle disease caused by an inability to synthesize DYSTROPHIN, which is involved with maintaining the integrity of the sarcolemma. Muscle fibers undergo a process that features degeneration and regeneration. Clinical manifestations include proximal weakness in the first few years of life, pseudohypertrophy, cardiomyopathy (see MYOCARDIAL DISEASES), and an increased incidence of impaired mentation. Becker muscular dystrophy is a closely related condition featuring a later onset of disease (usually adolescence) and a slowly progressive course. (Adams et al., Principles of Neurology, 6th ed, p1415)Muscular Dystrophy, AnimalDystrophin: A muscle protein localized in surface membranes which is the product of the Duchenne/Becker muscular dystrophy gene. Individuals with Duchenne muscular dystrophy usually lack dystrophin completely while those with Becker muscular dystrophy have dystrophin of an altered size. It shares features with other cytoskeletal proteins such as SPECTRIN and alpha-actinin but the precise function of dystrophin is not clear. One possible role might be to preserve the integrity and alignment of the plasma membrane to the myofibrils during muscle contraction and relaxation. MW 400 kDa.Mice, Inbred mdx: A strain of mice arising from a spontaneous MUTATION (mdx) in inbred C57BL mice. This mutation is X chromosome-linked and produces viable homozygous animals that lack the muscle protein DYSTROPHIN, have high serum levels of muscle ENZYMES, and possess histological lesions similar to human MUSCULAR DYSTROPHY. The histological features, linkage, and map position of mdx make these mice a worthy animal model of DUCHENNE MUSCULAR DYSTROPHY.Muscular Dystrophies, Limb-Girdle: A heterogenous group of inherited muscular dystrophy that can be autosomal dominant or autosomal recessive. There are many forms (called LGMDs) involving genes encoding muscle membrane proteins such as the sarcoglycan (SARCOGLYCANS) complex that interacts with DYSTROPHIN. The disease is characterized by progressing wasting and weakness of the proximal muscles of arms and legs around the HIPS and SHOULDERS (the pelvic and shoulder girdles).Myotonic Dystrophy: Neuromuscular disorder characterized by PROGRESSIVE MUSCULAR ATROPHY; MYOTONIA, and various multisystem atrophies. Mild INTELLECTUAL DISABILITY may also occur. Abnormal TRINUCLEOTIDE REPEAT EXPANSION in the 3' UNTRANSLATED REGIONS of DMPK PROTEIN gene is associated with Myotonic Dystrophy 1. DNA REPEAT EXPANSION of zinc finger protein-9 gene intron is associated with Myotonic Dystrophy 2.Muscular Dystrophy, Facioscapulohumeral: An autosomal dominant degenerative muscle disease characterized by slowly progressive weakness of the muscles of the face, upper-arm, and shoulder girdle. The onset of symptoms usually occurs in the first or second decade of life. Affected individuals usually present with impairment of upper extremity elevation. This tends to be followed by facial weakness, primarily involving the orbicularis oris and orbicularis oculi muscles. (Neuromuscul Disord 1997;7(1):55-62; Adams et al., Principles of Neurology, 6th ed, p1420)Muscular Dystrophy, Emery-Dreifuss: A heterogenous group of inherited muscular dystrophy without the involvement of nervous system. The disease is characterized by MUSCULAR ATROPHY; MUSCLE WEAKNESS; CONTRACTURE of the elbows; ACHILLES TENDON; and posterior cervical muscles; with or without cardiac features. There are several INHERITANCE PATTERNS including X-linked (X CHROMOSOME), autosomal dominant, and autosomal recessive gene mutations.Utrophin: An autosomally-encoded 376-kDa cytoskeletal protein that is similar in structure and function to DYSTROPHIN. It is a ubiquitously-expressed protein that plays a role in anchoring the CYTOSKELETON to the PLASMA MEMBRANE.Sarcoglycans: A family of transmembrane dystrophin-associated proteins that play a role in the membrane association of the DYSTROPHIN-ASSOCIATED PROTEIN COMPLEX.Dystroglycans: Dystrophin-associated proteins that play role in the formation of a transmembrane link between laminin-2 and DYSTROPHIN. Both the alpha and the beta subtypes of dystroglycan originate via POST-TRANSLATIONAL PROTEIN PROCESSING of a single precursor protein.Corneal Dystrophies, Hereditary: Bilateral hereditary disorders of the cornea, usually autosomal dominant, which may be present at birth but more frequently develop during adolescence and progress slowly throughout life. Central macular dystrophy is transmitted as an autosomal recessive defect.Muscle, Skeletal: A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.Muscular Dystrophy, Oculopharyngeal: An autosomal dominant hereditary disease that presents in late in life and is characterized by DYSPHAGIA and progressive ptosis of the eyelids. Mutations in the gene for POLY(A)-BINDING PROTEIN II have been associated with oculopharyngeal muscular dystrophy.Heterozygote Detection: Identification of genetic carriers for a given trait.Fuchs' Endothelial Dystrophy: Disorder caused by loss of endothelium of the central cornea. It is characterized by hyaline endothelial outgrowths on Descemet's membrane, epithelial blisters, reduced vision, and pain.Dystrophin-Associated Proteins: A group of proteins that associate with DYSTROPHIN at the CELL MEMBRANE to form the DYSTROPHIN-ASSOCIATED PROTEIN COMPLEX.Sarcolemma: The excitable plasma membrane of a muscle cell. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)Thymopoietins: Two closely related polypeptides (molecular weight 7,000) isolated from the thymus gland. These hormones induce the differentiation of prothymocytes to thymocytes within the thymus. They also cause a delayed impairment of neuromuscular transmission in vivo and are therefore believed to be the agent responsible for myasthenia gravis.Pedigree: The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.Creatine Kinase: A transferase that catalyzes formation of PHOSPHOCREATINE from ATP + CREATINE. The reaction stores ATP energy as phosphocreatine. Three cytoplasmic ISOENZYMES have been identified in human tissues: the MM type from SKELETAL MUSCLE, the MB type from myocardial tissue and the BB type from nervous tissue as well as a mitochondrial isoenzyme. Macro-creatine kinase refers to creatine kinase complexed with other serum proteins.Muscle Fibers, Skeletal: Large, multinucleate single cells, either cylindrical or prismatic in shape, that form the basic unit of SKELETAL MUSCLE. They consist of MYOFIBRILS enclosed within and attached to the SARCOLEMMA. They are derived from the fusion of skeletal myoblasts (MYOBLASTS, SKELETAL) into a syncytium, followed by differentiation.Retinal Dystrophies: A group of disorders involving predominantly the posterior portion of the ocular fundus, due to degeneration in the sensory layer of the RETINA; RETINAL PIGMENT EPITHELIUM; BRUCH MEMBRANE; CHOROID; or a combination of these tissues.Collagen Type VI: A non-fibrillar collagen that forms a network of MICROFIBRILS within the EXTRACELLULAR MATRIX of CONNECTIVE TISSUE. The alpha subunits of collagen type VI assemble into antiparallel, overlapping dimers which then align to form tetramers.Muscles: Contractile tissue that produces movement in animals.Exons: The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.Myoblasts: Embryonic (precursor) cells of the myogenic lineage that develop from the MESODERM. They undergo proliferation, migrate to their various sites, and then differentiate into the appropriate form of myocytes (MYOCYTES, SKELETAL; MYOCYTES, CARDIAC; MYOCYTES, SMOOTH MUSCLE).X Chromosome: The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.Muscle Proteins: The protein constituents of muscle, the major ones being ACTINS and MYOSINS. More than a dozen accessory proteins exist including TROPONIN; TROPOMYOSIN; and DYSTROPHIN.Dystrophin-Associated Protein Complex: A macromolecular complex of proteins that includes DYSTROPHIN and DYSTROPHIN-ASSOCIATED PROTEINS. It plays a structural role in the linking the CYTOSKELETON to the EXTRACELLULAR MATRIX.Neuromuscular Diseases: A general term encompassing lower MOTOR NEURON DISEASE; PERIPHERAL NERVOUS SYSTEM DISEASES; and certain MUSCULAR DISEASES. Manifestations include MUSCLE WEAKNESS; FASCICULATION; muscle ATROPHY; SPASM; MYOKYMIA; MUSCLE HYPERTONIA, myalgias, and MUSCLE HYPOTONIA.Caveolin 3: A caveolin that is expressed exclusively in MUSCLE CELLS and is sufficient to form CAVEOLAE in SARCOLEMMA. Mutations in caveolin 3 are associated with multiple muscle diseases including DISTAL MYOPATHY and LIMB-GIRDLE MUSCULAR DYSTROPHY.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Laminin: Large, noncollagenous glycoprotein with antigenic properties. It is localized in the basement membrane lamina lucida and functions to bind epithelial cells to the basement membrane. Evidence suggests that the protein plays a role in tumor invasion.Muscular Diseases: Acquired, familial, and congenital disorders of SKELETAL MUSCLE and SMOOTH MUSCLE.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Chromosomes, Human, Pair 4: A specific pair of GROUP B CHROMOSOMES of the human chromosome classification.Lamin Type A: A subclass of developmentally regulated lamins having a neutral isoelectric point. They are found to disassociate from nuclear membranes during mitosis.Cytoskeletal Proteins: Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.Cardiomyopathies: A group of diseases in which the dominant feature is the involvement of the CARDIAC MUSCLE itself. Cardiomyopathies are classified according to their predominant pathophysiological features (DILATED CARDIOMYOPATHY; HYPERTROPHIC CARDIOMYOPATHY; RESTRICTIVE CARDIOMYOPATHY) or their etiological/pathological factors (CARDIOMYOPATHY, ALCOHOLIC; ENDOCARDIAL FIBROELASTOSIS).Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Genetic Linkage: The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.Poly(A)-Binding Protein II: A poly(A) binding protein that is involved in promoting the extension of the poly A tails of MRNA. The protein requires a minimum of ten ADENOSINE nucleotides in order for binding to mRNA. Once bound it works in conjunction with CLEAVAGE AND POLYADENYLATION SPECIFICITY FACTOR to stimulate the rate of poly A synthesis by POLY A POLYMERASE. Once poly-A tails reach around 250 nucleotides in length poly(A) binding protein II no longer stimulates POLYADENYLATION. Mutations within a GCG repeat region in the gene for poly(A) binding protein II have been shown to cause the disease MUSCULAR DYSTROPHY, OCULOPHARYNGEAL.Genetic Therapy: Techniques and strategies which include the use of coding sequences and other conventional or radical means to transform or modify cells for the purpose of treating or reversing disease conditions.Diaphragm: The musculofibrous partition that separates the THORACIC CAVITY from the ABDOMINAL CAVITY. Contraction of the diaphragm increases the volume of the thoracic cavity aiding INHALATION.Regeneration: The physiological renewal, repair, or replacement of tissue.Muscle Strength: The amount of force generated by MUSCLE CONTRACTION. Muscle strength can be measured during isometric, isotonic, or isokinetic contraction, either manually or using a device such as a MUSCLE STRENGTH DYNAMOMETER.Neuroaxonal Dystrophies: A nonspecific term referring both to the pathologic finding of swelling of distal portions of axons in the brain and to disorders which feature this finding. Neuroaxonal dystrophy is seen in various genetic diseases, vitamin deficiencies, and aging. Infantile neuroaxonal dystrophy is an autosomal recessive disease characterized by arrested psychomotor development at 6 months to 2 years of age, ataxia, brain stem dysfunction, and quadriparesis. Juvenile and adult forms also occur. Pathologic findings include brain atrophy and widespread accumulation of axonal spheroids throughout the neuroaxis, peripheral nerves, and dental pulp. (From Davis & Robertson, Textbook of Neuropathology, 2nd ed, p927)Sarcoglycanopathies: Deficiencies or mutations in the genes for the SARCOGLYCAN COMPLEX subunits. A variety of phenotypes are associated with these mutations including a subgroup of autosomal recessive limb girdle muscular dystrophies, cardiomyopathies, and respiratory deficiency.Walker-Warburg Syndrome: Rare autosomal recessive lissencephaly type 2 associated with congenital MUSCULAR DYSTROPHY and eye anomalies (e.g., RETINAL DETACHMENT; CATARACT; MICROPHTHALMOS). It is often associated with additional brain malformations such as HYDROCEPHALY and cerebellar hypoplasia and is the most severe form of the group of related syndromes (alpha-dystroglycanopathies) with common congenital abnormalities in the brain, eye and muscle development.Genes, Recessive: Genes that influence the PHENOTYPE only in the homozygous state.Muscle Development: Developmental events leading to the formation of adult muscular system, which includes differentiation of the various types of muscle cell precursors, migration of myoblasts, activation of myogenesis and development of muscle anchorage.Calpain: Cysteine proteinase found in many tissues. Hydrolyzes a variety of endogenous proteins including NEUROPEPTIDES; CYTOSKELETAL PROTEINS; proteins from SMOOTH MUSCLE; CARDIAC MUSCLE; liver; platelets; and erythrocytes. Two subclasses having high and low calcium sensitivity are known. Removes Z-discs and M-lines from myofibrils. Activates phosphorylase kinase and cyclic nucleotide-independent protein kinase. This enzyme was formerly listed as EC 126.96.36.199.Heterozygote: An individual having different alleles at one or more loci regarding a specific character.Pregnenediones: Unsaturated pregnane derivatives containing two keto groups on side chains or ring structures.Mice, Inbred C57BLMuscle Weakness: A vague complaint of debility, fatigue, or exhaustion attributable to weakness of various muscles. The weakness can be characterized as subacute or chronic, often progressive, and is a manifestation of many muscle and neuromuscular diseases. (From Wyngaarden et al., Cecil Textbook of Medicine, 19th ed, p2251)Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Plectin: A cytoskeletal linker protein with a molecular weight of greater than 500 kDa. It binds INTERMEDIATE FILAMENTS; MICROTUBULES; and ACTIN CYTOSKELETON and plays a central role in the organization and stability of the CYTOSKELETON. Plectin is phosphorylated by CALMODULIN KINASE; PROTEIN KINASE A; and PROTEIN KINASE C.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Satellite Cells, Skeletal Muscle: Elongated, spindle-shaped, quiescent myoblasts lying in close contact with adult skeletal muscle. They are thought to play a role in muscle repair and regeneration.Myostatin: A growth differentiation factor that is a potent inhibitor of SKELETAL MUSCLE growth. It may play a role in the regulation of MYOGENESIS and in muscle maintenance during adulthood.Dependovirus: A genus of the family PARVOVIRIDAE, subfamily PARVOVIRINAE, which are dependent on a coinfection with helper adenoviruses or herpesviruses for their efficient replication. The type species is Adeno-associated virus 2.Morpholinos: Synthetic analogs of NUCLEIC ACIDS composed of morpholine ring derivatives (MORPHOLINES) linked by phosphorodimidates. One standard DNA nucleic acid base (ADENINE; GUANINE; CYTOSINE; OR THYMINE) is bound to each morpholine ring.Myositis: Inflammation of a muscle or muscle tissue.DNA Mutational Analysis: Biochemical identification of mutational changes in a nucleotide sequence.Prenatal Diagnosis: Determination of the nature of a pathological condition or disease in the postimplantation EMBRYO; FETUS; or pregnant female before birth.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.Genetic Counseling: An educational process that provides information and advice to individuals or families about a genetic condition that may affect them. The purpose is to help individuals make informed decisions about marriage, reproduction, and other health management issues based on information about the genetic disease, the available diagnostic tests, and management programs. Psychosocial support is usually offered.Consanguinity: The magnitude of INBREEDING in humans.Connectin: A giant elastic protein of molecular mass ranging from 2,993 kDa (cardiac), 3,300 kDa (psoas), to 3,700 kDa (soleus) having a kinase domain. The amino- terminal is involved in a Z line binding, and the carboxy-terminal region is bound to the myosin filament with an overlap between the counter-connectin filaments at the M line.Reflex Sympathetic Dystrophy: A syndrome characterized by severe burning pain in an extremity accompanied by sudomotor, vasomotor, and trophic changes in bone without an associated specific nerve injury. This condition is most often precipitated by trauma to soft tissue or nerve complexes. The skin over the affected region is usually erythematous and demonstrates hypersensitivity to tactile stimuli and erythema. (Adams et al., Principles of Neurology, 6th ed, p1360; Pain 1995 Oct;63(1):127-33)Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Myoblasts, Skeletal: Precursor cells destined to differentiate into skeletal myocytes (MYOCYTES, SKELETAL).Cardiomyopathy, Dilated: A form of CARDIAC MUSCLE disease that is characterized by ventricular dilation, VENTRICULAR DYSFUNCTION, and HEART FAILURE. Risk factors include SMOKING; ALCOHOL DRINKING; HYPERTENSION; INFECTION; PREGNANCY; and mutations in the LMNA gene encoding LAMIN TYPE A, a NUCLEAR LAMINA protein.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Syndrome: A characteristic symptom complex.Muscle Cells: Mature contractile cells, commonly known as myocytes, that form one of three kinds of muscle. The three types of muscle cells are skeletal (MUSCLE FIBERS, SKELETAL), cardiac (MYOCYTES, CARDIAC), and smooth (MYOCYTES, SMOOTH MUSCLE). They are derived from embryonic (precursor) muscle cells called MYOBLASTS.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Vitelliform Macular Dystrophy: Autosomal dominant hereditary maculopathy with childhood-onset accumulation of LIPOFUSION in RETINAL PIGMENT EPITHELIUM. Affected individuals develop progressive central acuity loss, and distorted vision (METAMORPHOPSIA). It is associated with mutations in bestrophin, a chloride channel.Biopsy: Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.Chromosome Deletion: Actual loss of portion of a chromosome.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Electroretinography: Recording of electric potentials in the retina after stimulation by light.Genetic Testing: Detection of a MUTATION; GENOTYPE; KARYOTYPE; or specific ALLELES associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing.Integrin alpha Chains: The alpha subunits of integrin heterodimers (INTEGRINS), which mediate ligand specificity. There are approximately 18 different alpha chains, exhibiting great sequence diversity; several chains are also spliced into alternative isoforms. They possess a long extracellular portion (1200 amino acids) containing a MIDAS (metal ion-dependent adhesion site) motif, and seven 60-amino acid tandem repeats, the last 4 of which form EF HAND MOTIFS. The intracellular portion is short with the exception of INTEGRIN ALPHA4.Evans Blue: An azo dye used in blood volume and cardiac output measurement by the dye dilution method. It is very soluble, strongly bound to plasma albumin, and disappears very slowly.Glycerol Kinase: An enzyme that catalyzes the formation of glycerol 3-phosphate from ATP and glycerol. Dihydroxyacetone and L-glyceraldehyde can also act as acceptors; UTP and, in the case of the yeast enzyme, ITP and GTP can act as donors. It provides a way for glycerol derived from fats or glycerides to enter the glycolytic pathway. EC 188.8.131.52.Genes, Dominant: Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.Gene Deletion: A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.Lamins: Nuclear matrix proteins that are structural components of the NUCLEAR LAMINA. They are found in most multicellular organisms.Muscle Contraction: A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.Frameshift Mutation: A type of mutation in which a number of NUCLEOTIDES deleted from or inserted into a protein coding sequence is not divisible by three, thereby causing an alteration in the READING FRAMES of the entire coding sequence downstream of the mutation. These mutations may be induced by certain types of MUTAGENS or may occur spontaneously.Codon, Nonsense: An amino acid-specifying codon that has been converted to a stop codon (CODON, TERMINATOR) by mutation. Its occurance is abnormal causing premature termination of protein translation and results in production of truncated and non-functional proteins. A nonsense mutation is one that converts an amino acid-specific codon to a stop codon.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Scoliosis: An appreciable lateral deviation in the normally straight vertical line of the spine. (Dorland, 27th ed)Membrane Glycoproteins: Glycoproteins found on the membrane or surface of cells.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Intellectual Disability: Subnormal intellectual functioning which originates during the developmental period. This has multiple potential etiologies, including genetic defects and perinatal insults. Intelligence quotient (IQ) scores are commonly used to determine whether an individual has an intellectual disability. IQ scores between 70 and 79 are in the borderline range. Scores below 67 are in the disabled range. (from Joynt, Clinical Neurology, 1992, Ch55, p28)Fibrosis: Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury.Nitric Oxide Synthase Type I: A CALCIUM-dependent, constitutively-expressed form of nitric oxide synthase found primarily in NERVE TISSUE.Genetic Markers: A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.Sequence Deletion: Deletion of sequences of nucleic acids from the genetic material of an individual.Oligoribonucleotides, Antisense: Short fragments of RNA that are used to alter the function of target RNAs or DNAs to which they hybridize.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Mutation, Missense: A mutation in which a codon is mutated to one directing the incorporation of a different amino acid. This substitution may result in an inactive or unstable product. (From A Dictionary of Genetics, King & Stansfield, 5th ed)Genetic Vectors: DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.Muscular Atrophy: Derangement in size and number of muscle fibers occurring with aging, reduction in blood supply, or following immobilization, prolonged weightlessness, malnutrition, and particularly in denervation.Trinucleotide Repeat Expansion: An increased number of contiguous trinucleotide repeats in the DNA sequence from one generation to the next. The presence of these regions is associated with diseases such as FRAGILE X SYNDROME and MYOTONIC DYSTROPHY. Some CHROMOSOME FRAGILE SITES are composed of sequences where trinucleotide repeat expansion occurs.Oligonucleotides, Antisense: Short fragments of DNA or RNA that are used to alter the function of target RNAs or DNAs to which they hybridize.Myocardium: The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.Myotonic Disorders: Diseases characterized by MYOTONIA, which may be inherited or acquired. Myotonia may be restricted to certain muscles (e.g., intrinsic hand muscles) or occur as a generalized condition.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Homozygote: An individual in which both alleles at a given locus are identical.Glycosylation: The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Creatine Kinase, MM Form: An isoenzyme of creatine kinase found in the MUSCLE.Mannosyltransferases: Enzymes that catalyze the transfer of mannose from a nucleoside diphosphate mannose to an acceptor molecule which is frequently another carbohydrate. The group includes EC 184.108.40.206, EC 220.127.116.11, EC 18.104.22.168, and EC 22.214.171.124.Facial Muscles: Muscles of facial expression or mimetic muscles that include the numerous muscles supplied by the facial nerve that are attached to and move the skin of the face. (From Stedman, 25th ed)DNA Probes: Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.N-Acetylglucosaminyltransferases: Enzymes that catalyze the transfer of N-acetylglucosamine from a nucleoside diphosphate N-acetylglucosamine to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.-.Retinal Degeneration: A retrogressive pathological change in the retina, focal or generalized, caused by genetic defects, inflammation, trauma, vascular disease, or aging. Degeneration affecting predominantly the macula lutea of the retina is MACULAR DEGENERATION. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p304)RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Poly(A)-Binding Protein I: A poly(A) binding protein that has a variety of functions such as mRNA stabilization and protection of RNA from nuclease activity. Although poly(A) binding protein I is considered a major cytoplasmic RNA-binding protein it is also found in the CELL NUCLEUS and may be involved in transport of mRNP particles.Fluorescent Antibody Technique: Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.Injections, Intramuscular: Forceful administration into a muscle of liquid medication, nutrient, or other fluid through a hollow needle piercing the muscle and any tissue covering it.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Mosaicism: The occurrence in an individual of two or more cell populations of different chromosomal constitutions, derived from a single ZYGOTE, as opposed to CHIMERISM in which the different cell populations are derived from more than one zygote.Polymorphism, Restriction Fragment Length: Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.Oxepins: Compounds based on a 7-membered heterocyclic ring including an oxygen. They can be considered a medium ring ether. A natural source is the MONTANOA plant genus. Some dibenzo-dioxepins, called depsidones, are found in GARCINIA plants.Reading Frames: The three possible sequences of CODONS by which GENETIC TRANSLATION may occur from one nucleotide sequence. A segment of mRNA 5'AUCCGA3' could be translated as 5'AUC.. or 5'UCC.. or 5'CCG.., depending on the location of the START CODON.Mice, Mutant Strains: Mice bearing mutant genes which are phenotypically expressed in the animals.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Neuromuscular Junction: The synapse between a neuron and a muscle.Point Mutation: A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.Disease Progression: The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.Shoulder: Part of the body in humans and primates where the arms connect to the trunk. The shoulder has five joints; ACROMIOCLAVICULAR joint, CORACOCLAVICULAR joint, GLENOHUMERAL joint, scapulathoracic joint, and STERNOCLAVICULAR joint.Retinitis Pigmentosa: Hereditary, progressive degeneration of the neuroepithelium of the retina characterized by night blindness and progressive contraction of the visual field.Distal Myopathies: A heterogeneous group of genetic disorders characterized by progressive MUSCULAR ATROPHY and MUSCLE WEAKNESS beginning in the hands, the legs, or the feet. Most are adult-onset autosomal dominant forms. Others are autosomal recessive.Nuclear Envelope: The membrane system of the CELL NUCLEUS that surrounds the nucleoplasm. It consists of two concentric membranes separated by the perinuclear space. The structures of the envelope where it opens to the cytoplasm are called the nuclear pores (NUCLEAR PORE).Chromosome Banding: Staining of bands, or chromosome segments, allowing the precise identification of individual chromosomes or parts of chromosomes. Applications include the determination of chromosome rearrangements in malformation syndromes and cancer, the chemistry of chromosome segments, chromosome changes during evolution, and, in conjunction with cell hybridization studies, chromosome mapping.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Gene Transfer Techniques: The introduction of functional (usually cloned) GENES into cells. A variety of techniques and naturally occurring processes are used for the gene transfer such as cell hybridization, LIPOSOMES or microcell-mediated gene transfer, ELECTROPORATION, chromosome-mediated gene transfer, TRANSFECTION, and GENETIC TRANSDUCTION. Gene transfer may result in genetically transformed cells and individual organisms.Transgenes: Genes that are introduced into an organism using GENE TRANSFER TECHNIQUES.Deoxyribonuclease HindIII: One of the Type II site-specific deoxyribonucleases (EC 126.96.36.199). It recognizes and cleaves the sequence A/AGCTT at the slash. HindIII is from Haemophilus influenzae R(d). Numerous isoschizomers have been identified. EC 3.1.21.-.Projective Techniques: Techniques to reveal personality attributes by responses to relatively unstructured or ambiguous stimuli.Respiratory Muscles: These include the muscles of the DIAPHRAGM and the INTERCOSTAL MUSCLES.Mazindol: Tricyclic anorexigenic agent unrelated to and less toxic than AMPHETAMINE, but with some similar side effects. It inhibits uptake of catecholamines and blocks the binding of cocaine to the dopamine uptake transporter.Age of Onset: The age, developmental stage, or period of life at which a disease or the initial symptoms or manifestations of a disease appear in an individual.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Caveolins: The main structural proteins of CAVEOLAE. Several distinct genes for caveolins have been identified.RNA Splicing: The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.Haplotypes: The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.MyoD Protein: A myogenic regulatory factor that controls myogenesis. Though it is not clear how its function differs from the other myogenic regulatory factors, MyoD appears to be related to fusion and terminal differentiation of the muscle cell.Alternative Splicing: A process whereby multiple RNA transcripts are generated from a single gene. Alternative splicing involves the splicing together of other possible sets of EXONS during the processing of some, but not all, transcripts of the gene. Thus a particular exon may be connected to any one of several alternative exons to form a mature RNA. The alternative forms of mature MESSENGER RNA produce PROTEIN ISOFORMS in which one part of the isoforms is common while the other parts are different.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Epidermolysis Bullosa Simplex: A form of epidermolysis bullosa characterized by serous bullae that heal without scarring. Mutations in the genes that encode KERATIN-5 and KERATIN-14 have been associated with several subtypes of epidermolysis bullosa simplex.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Blotting, Southern: A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.Stanford-Binet Test: An individual intelligence test designed primarily for school children to predict school performance and the ability to adjust to everyday demands.Genetic Diseases, X-Linked: Genetic diseases that are linked to gene mutations on the X CHROMOSOME in humans (X CHROMOSOME, HUMAN) or the X CHROMOSOME in other species. Included here are animal models of human X-linked diseases.Cardiotoxins: Agents that have a damaging effect on the HEART. Such damage can occur from ALKYLATING AGENTS; FREE RADICALS; or metabolites from OXIDATIVE STRESS and in some cases is countered by CARDIOTONIC AGENTS. Induction of LONG QT SYNDROME or TORSADES DE POINTES has been the reason for viewing some drugs as cardiotoxins.Phosphodiesterase 5 Inhibitors: Compounds that specifically inhibit PHOSPHODIESTERASE 5.Neuromuscular Blockade: The intentional interruption of transmission at the NEUROMUSCULAR JUNCTION by external agents, usually neuromuscular blocking agents. It is distinguished from NERVE BLOCK in which nerve conduction (NEURAL CONDUCTION) is interrupted rather than neuromuscular transmission. Neuromuscular blockade is commonly used to produce MUSCLE RELAXATION as an adjunct to anesthesia during surgery and other medical procedures. It is also often used as an experimental manipulation in basic research. It is not strictly speaking anesthesia but is grouped here with anesthetic techniques. The failure of neuromuscular transmission as a result of pathological processes is not included here.Contracture: Prolonged shortening of the muscle or other soft tissue around a joint, preventing movement of the joint.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Necrosis: The pathological process occurring in cells that are dying from irreparable injuries. It is caused by the progressive, uncontrolled action of degradative ENZYMES, leading to MITOCHONDRIAL SWELLING, nuclear flocculation, and cell lysis. It is distinct it from APOPTOSIS, which is a normal, regulated cellular process.