Genetic Analysis of Hereditary Ataxias in Peru Identifies SCA10 Families with Incomplete Penetrance
- on behalf of Rede Neurogenetica,
- Mario Cornejo-Olivas(Author),
- Miguel Inca-Martinez(Author),
- Raphael Machado Castilhos(Author),
- Gabriel Vasata Furtado(Author),
- Eduardo Preusser Mattos(Author)
- Universidad Peruana Cayetano Heredia,
- docencia y atención especializada en epilepsia,
- Cleveland Clinic Foundation,
- Federal University of Rio Grande do Sul,
- Universidade Federal Do Rio Grande Do sul,
- Instituto de Genética Médica Populacional (INAGEMP)
Publication Information
Output type
Original language
EnglishPages from-to (Number of pages)
Pages 208-215 (8 pages)Journal (Volume, Issue Number)
Cerebellum (Volume 19, Issue 2)Publication milestones
- Published - 01/04/2020
Publication status
ISSN
1473-4222Publication IDs
- Scopus: 85077629385
- PubMed: 31900855
Abstract
Relative frequency of hereditary ataxias remains unknown in many regions of Latin America. We described the relative frequency in spinocerebellar ataxias (SCA) due to (CAG)n and to (ATTCT)n expansions, as well as Friedreich ataxia (FRDA), among cases series of ataxic individuals from Peru. Among ataxic index cases from 104 families (38 of them with and 66 without autosomal dominant pattern of inheritance), we identified 22 SCA10, 8 SCA2, 3 SCA6, 2 SCA3, 2 SCA7, 1 SCA1, and 9 FRDA cases (or families). SCA10 was by far the most frequent one. Findings in SCA10 and FRDA families were of note. Affected genitors were not detected in 7 out of 22 SCA10 nuclear families; then overall maximal penetrance of SCA10 was estimated as 85%; in multiplex families, penetrance was 94%. Two out of nine FRDA cases carried only one allele with a GAA expansion. SCA10 was the most frequent hereditary ataxia in Peru. Our data suggested that ATTCT expansions at ATXN10 might not be fully penetrant and/or instability between generations might frequently cross the limits between non-penetrant and penetrant lengths. A unique distribution of inherited ataxias in Peru requires specific screening panels, considering SCA10 as first line of local diagnosis guidelines.