Successive generations chromosome microsatellites gene contains trinucleotide repeat expansion. Medical search. Frequent questions

21 allelic mutations have been discovered in the APP gene. (findzebra.com)
We hypothesize that there might be at least three types of autism susceptibility genes/mutations that can be (i) specific to an individual patient or family, (ii) in a genetically isolated sub-population and (iii) a common factor shared amongst different populations. (neurotransmitter.net)
The genes/mutations could act alone or interact with other genetic and/or epigenetic or environmental factors, causing autism or related disorders. (neurotransmitter.net)

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] 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)
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)
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)
The first stage involved identifying, in unrelated subjects showing linkage to 2q24-q33, genetic variants in exons and flanking sequence within candidate genes and comparing the frequency of the variants between autistic and unrelated nonautistic subjects. (neurotransmitter.net)

Almost every chromosome is affected by numeric or structural aberrations. (neurotransmitter.net)

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)

Many human genes, including one for a protein that controls cholesterol levels in the blood, show co-dominance too. (wikipedia.org)
This subtype is due to a mutation in the APP gene (21q21.2), encoding the beta-amyloid precursor protein. (findzebra.com)

citation needed] Many other genes have multiple alleles, including the human genes for ABO blood type. (wikipedia.org)

An individual usually has only two copies of each gene, but many different alleles are often found within a population. (wikipedia.org)
Negative association findings and research involving the serotonin transporter gene, FMR1, RELN, WNT2, HOXA1, and HOXB1 genes may be found elsewhere on this site . (neurotransmitter.net)

These guarantee onset of early-onset familial Alzheimer disease and all occur in the region of the APP gene that encodes the Aβ domain. (findzebra.com)
The authors recently mapped a susceptibility locus for autism to chromosome region 2q24-q33 (MIM number 606053). (neurotransmitter.net)
In the present study, genes across the 2q24-q33 interval were analyzed to identify an autism susceptibility gene in this region. (neurotransmitter.net)

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)

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)
Referring to both alleles of a gene . (nih.gov)

Nevertheless, the principle of uniformity works, as all offspring in the F1-generation have the same genotype and same phenotype. (wikipedia.org)

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)

may also refer to an individual with a balanced chromosome rearrangement. (nih.gov)

These laws describe the inheritance of traits linked to single genes on chromosomes in the nucleus. (wikipedia.org)
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)

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)
Domestic cats have a gene with a similar effect on the X-chromosome. (wikipedia.org)

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)