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Study of the Huntington's disease IT ‐15 gene in different ethnic groups in Ecuador
Author(s) -
PazyMiño C.,
SalazarRuales C.,
GarcíaCárdenas J.M.,
CabreraAndrade A.,
LópezCortés A.,
PavónRealpe V.H.,
Eras E.,
Rodriguez P C,
Domínguez Enríquez J.P.,
Cusco Cuzco C.D.,
Navarrete Socasi D.C.,
Leone P.E.
Publication year - 2017
Publication title -
clinical genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 102
eISSN - 1399-0004
pISSN - 0009-9163
DOI - 10.1111/cge.13028
Subject(s) - penetrance , sanger sequencing , genetics , allele , ethnic group , indigenous , population , demography , allele frequency , disease , mutation , gene , biology , medicine , ecology , sociology , anthropology , phenotype
This study aims to establish the current state of the IT ‐15 ( HTT ) gene in different Ecuadorian ethnic groups and patients by determining CAG triplet repeats, compared with the ethnicity of individuals. A total of 412 individuals were studied using nested polymerase chain reaction and Sanger sequencing: 75 individuals were indigenous (Kichwas), 211 mestizos, and 65 Afro‐Ecuadorians. We included 31 patients who were clinically diagnosed with Huntington's disease (HD) and relatives of the affected patients ( n = 30). Moreover, we correlated the presence of HD in Ecuadorian patients with 46 genetic ancestry‐informative insertion‐deletion polymorphic markers. We found that 77.20% had <28 CAG repetitions, 18.80% had mutable alleles, 2.27% had incomplete penetrance, and 1.70% reflected >39 repetitions. The average of CAG repetitions was 24 ± 3 for indigenous people; 28 ± 2 for mestizos; and 24 ± 3.2 repetitions for the Afro‐Ecuadorians. The ancestral component showed that the main ancestry corresponded to Native Americans (0.873) and European ascendants (0.145), Africans were less represented in the evaluated population (0.018). There was a significant difference between the number of CAG repeats in mestizos and indigenous people ( P < .01), suggesting that the Ecuadorian mestizo population has a risk factor for the gene mutation.