citation needed] When genes are located on the same chromosome and no crossing over took place before the segregation of the chromosomes into the gametes, the genetic traits will be inherited in connection, because of the genetic linkage. (wikipedia.org)
Domestic cats have a gene with a similar effect on the X-chromosome. (wikipedia.org)
Its molecular basis is an expansion of a CTG repeat in the 3′ untranslated region (UTR) of the DMPK gene on chromosome 19. (bmj.com)
Fragile X Syndrome (FXS) is caused by expansions of a CGG triplet repeat in the FMR1 gene on the X chromosome, similar to trinucleotide expansions associated with other diseases such as Huntington's disease and myotonic dystrophy . (softgenetics.com)
Identification of a gene (FMR-1) containing a CGG repeat coincident with a breakpoint cluster region exhibiting length variation in fragile X syndrome. (org.ua)
Pathogenic2
However, pathogenic loci bear expanded alleles of up to several hundred or even thousand repeats in severe cases. (bmj.com)
As with many other tandemly repeated microsatellite sequences, pathogenic TNRs are highly unstable in both the somatic and germ cell lineage, leading to expansions and contractions in the length of the repeats in successive cell or individual generations. (bmj.com)
Chromosomes1
These laws describe the inheritance of traits linked to single genes on chromosomes in the nucleus. (wikipedia.org)
Instability2
31 Therefore, we have hypothesised that mutagenic stress could result in an induction of instability of unexpanded TNR sequences, leading to an increase in the frequency of spontaneously occurring contractions/expansions in repeat number. (bmj.com)
Variation of the CGG repeat at the fragile X site results in genetic instability: resolution of the Sherman paradox. (org.ua)
Full mutation1
The full mutation in the FMR-1 gene of male fragile X patients is absent in their sperm. (org.ua)
Alleles10
In cases of co-dominance, the genetic traits of both different alleles of the same gene-locus are clearly expressed in the phenotype. (wikipedia.org)
citation needed] In Mendelian inheritance, genes have only two alleles, such as a and A. Mendel consciously chose pairs of genetic traits, represented by two alleles for his inheritance experiments. (wikipedia.org)
In nature, such genes often exist in several different forms and are therefore said to have multiple alleles. (wikipedia.org)
An individual usually has only two copies of each gene, but many different alleles are often found within a population. (wikipedia.org)
A rabbit's coat color is determined by a single gene that has at least four different alleles. (wikipedia.org)
In the genes for the dog coat colours there are four alleles on the Agouti-locus. (wikipedia.org)
citation needed] Many other genes have multiple alleles, including the human genes for ABO blood type. (wikipedia.org)
citation needed] If one or more genes cannot be expressed because of another genetic factor hindering their expression, this epistasis can make it impossible even for dominant alleles on certain other gene-loci to have an effect on the phenotype. (wikipedia.org)
In addition, much of the evidence for the mechanisms that are thought to produce repeat expansion in pathological TNRs are dismissed as irrelevant for normal alleles. (bmj.com)
10 These factors are not mutually exclusive and include the purity and length of the repeated sequence, 7, 11 age of individuals, 6, 7 mitotic drive, 12 the relative position of the TNR with respect to adjacent origins of DNA replication, 13 and mutations in genes involved in DNA repair, replication, and recombination. (bmj.com)
[18] W?hrle D, Hennig I, Vogel W, Steinbach P. Mitotic stability of fragile X mutations in differentiated cells indicates early post-conceptional trinucleotide repeat expansion. (org.ua)
Homozygous1
Mendel's principle of segregation of genes applies too, as in the F2-generation homozygous individuals with the phenotypes of the P-generation appear. (wikipedia.org)
Genetic1
6- 8 Expansions in the number of TNRs are known to be a molecular basis of genetic anticipation, 9 the progressively earlier age of onset of a disease with increasing severity in successive generations. (bmj.com)
Human1
Many human genes, including one for a protein that controls cholesterol levels in the blood, show co-dominance too. (wikipedia.org)
Disorders1
In studies of FXS, the number of repeats and methylation status of the gene are associated with a constellation of disorders that impact a broad range of ages and populations. (softgenetics.com)
Single2
To test this hypothesis, we analysed normal length TNR sequences at a single repeat resolution by radioactive PCR and denaturating polyacrylamide gels, using DNA from multiple single cell clones expanded in the presence or absence of mitomycin-C (MMC), a mutagenic agent able to induce interstrand DNA cross links, strand breaks, and replication blockage. (bmj.com)
Final sample report from a single dye chemistry to calculate the number of CGG repeats for each fragment, including a similar Header, Conclusion/Authorization box, Electropherogram and Report Table with the calculated number of triplet repeats, size in bp, and peak height for each fragment. (softgenetics.com)
Analysis2
Analysis parameters are easily customized to fit the SOP for the laboratory, with automated calculation of Correction Factors using a control sample with fragments of known CGG repeat length or a .txt file with the CGG repeat and bp size. (softgenetics.com)
Final sample report from two-dye methylation chemistry includes: Header with details from user management and analysis parameters, Conclusion/Authorization box, Electropherogram and Report table The report table contains the sample metrics for the digestion control and reference fragment, the calculated number of triplet repeats, size of fragment in base pairs, peak height, and calculated percent methylation for each fragment. (softgenetics.com)
Produce1
People with the heterozygous form of this gene produce two different forms of the protein, each with a different effect on cholesterol levels. (wikipedia.org)
Length2
Advances in PCR-methods allow researchers to directly determine repeat length and methylation status using a two-color PCR approach. (softgenetics.com)
The linked Fragile X application automatically coordinates edits in Control and Digestion channels for two-dye projects and performs repetitive calculations, converting fragment size to repeat length and calculating percent methylation. (softgenetics.com)