Population genetics of the fragile-X syndrome: multiallelic model for the FMR1 locus.
AUTOR(ES)
Morton, N E
RESUMO
A model is developed to account for recent molecular observations. It postulates four alleles: normal (N), small rather stable insert (S), larger, unstable insert (Z), and large insert (L). The last-named allele causes the fragile-X phenotype, inactivation of the FMR1 locus by methylation, and mental impairment; the FMR1 locus (for fragile-X mental retardation locus 1) resides in the FRAXA region. When this model is fit to pre-molecular data, the Z allele appears to be no more frequent than L, while the S allele is polymorphic. Predictions of the model are in reasonable agreement with observation and suggest much more powerful tests of molecular data, including the Laird hypothesis that conversion of Z to L does not occur in active X chromosomes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=525664Documentos Relacionados
- Prenatal diagnosis of the fragile X syndrome: loss of mutation owing to a double recombinant or gene conversion event at the FMR1 locus.
- Frontostriatal deficits in fragile X syndrome: Relation to FMR1 gene expression
- Neurological findings in patients with the fragile-X syndrome.
- An n-allele model for progressive amplification in the FMR1 locus.
- General overgrowth in the fragile X syndrome: variability in the phenotypic expression of the FMR1 gene mutation