1. Founder effect and ancestral origin of the spinocerebellar ataxia type 7 (SCA7) mutation in Mexican families
- Author
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Adriana Ochoa-Morales, Carla Marquez-Luna, M. Teresa Villarreal-Molina, Victor Acuña-Alonzo, Sandra Romero-Hidalgo, M. Elisa Alonso-Vilatela, Petra Yescas-Gómez, Leticia Martínez-Ruano, Samuel Canizales-Quinteros, and Lizbeth García-Velázquez
- Subjects
Adult ,Genetic Markers ,Ataxin 7 ,Adolescent ,Genotype ,DNA Mutational Analysis ,Nerve Tissue Proteins ,Biology ,White People ,Cellular and Molecular Neuroscience ,Young Adult ,Genetics ,medicine ,Humans ,Spinocerebellar Ataxias ,Allele ,Child ,Mexico ,Genetics (clinical) ,Alleles ,Aged ,Oligonucleotide Array Sequence Analysis ,Aged, 80 and over ,Ataxin-7 ,Family Health ,Principal Component Analysis ,Geography ,Haplotype ,Autosomal dominant trait ,Chromosome Mapping ,Middle Aged ,medicine.disease ,Founder Effect ,Haplotypes ,Child, Preschool ,Mutation (genetic algorithm) ,Mutation ,Spinocerebellar ataxia ,biology.protein ,Disease Progression ,Microsatellite ,Founder effect ,Microsatellite Repeats - Abstract
Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant disease characterized by progressive cerebellar ataxia and macular degeneration causing progressive blindness. It accounts for 1 to 11.6 % of spinocerebellar ataxias (SCAs) cases worldwide and for 7.4 % of SCA7 cases in Mexico. We identified a cluster of SCA7 families who resided in a circumscribed area of Veracruz and investigated whether the high incidence of the disease in this region was due to a founder effect. A total of 181 individuals from 20 families were studied. Four microsatellite markers and one SNP flanking the ATNX7 gene were genotyped and the ancestral origin and local ancestry analysis of the SCA7 mutation were evaluated. Ninety individuals from 19 families had the SCA7 mutation; all were found to share a common haplotype, suggesting that the mutation in these families originated from a common ancestor. Ancestral origin and local ancestry analysis of SCA7 showed that the chromosomal segment containing the mutation was of European origin. We here present evidence strongly suggesting that the high frequency of SCA7 in Veracruz is due to a founder effect and that the mutation is most likely of European origin with greatest resemblance to the Finnish population.
- Published
- 2013