A complex mutable polymorphism located within the fragile X gene.

N Zhong; C Dobkin; W T Brown

doi:10.1038/ng1193-248

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PubMed · 8275089

A complex mutable polymorphism located within the fragile X gene.

N Zhong·C Dobkin·W T Brown

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Abstract

While studying founder chromosomes in the fragile X syndrome, we have unexpectedly found linkage equilibrium to FRAXAC2, an Alu-associated microsatellite within the defective gene, FMR-1. DNA sequencing of 265 chromosomes revealed 39 alleles and a complex microsatellite of form (GT)x-C-(TA)y-(T)z. A mutation rate of 3.3% was observed but only among fragile X maternally derived meioses. Finding a second mutable locus within FMR-1 suggests that the target for tandem repeat instability may not be confined to the (CGG)n repeat alone and raises the possibility of an FMR-1 mutation mechanism involving microsatellites.

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Base Sequence Chromosome Fragility DNA, Satellite Female Fragile X Syndrome Genetic Markers Humans Linkage Disequilibrium Male Meiosis Molecular Sequence Data Pedigree Polymorphism, Genetic Repetitive Sequences, Nucleic Acid Journal Article

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N Zhong, C Dobkin, W T Brown. 1993. A complex mutable polymorphism located within the fragile X gene.. https://doi.org/10.1038/ng1193-248

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