Genetic admixture of European FRDA genes is the cause of Friedreich ataxia in the Mexican population

Apolipoprotein E ε4 allele is associated with Parkinson disease risk in a Mexican Mestizo population

“…Mexican Mestizo populations consist of gene pools derived from three primary sources: Amerindian, European‐Spanish, and African in different proportions depending on the geographic region and socio‐economic status. In our study, PD cases and control individuals were of comparable ethnic origin (Mexican Mestizo) with a low socio‐economic status and mainly from the central region of Mexico, which would indicate a major Amerindian contribution, followed by European‐Spanish and with almost no African component 13, 14…”

Impact of genetic ancestry and sociodemographic status on the clinical expression of systemic lupus erythematosus in American Indian–European populations

“…To assess this problem, we included genotypes from 80 Nahua individuals as a reference panel of American Indians. The Nahuas are a relatively isolated population of American Indian origin (25), but it should be borne in mind that these represent primarily North American indigenous groups. Another factor of self‐reported ethnicity errors can be a lack of awareness of one's true ethnicity, while others may identify with 1 ethnic group despite their admixed background; yet another factor is the subjectivity of the perception that a physician may have, possibly primarily based on skin or hair color or some particular facial features with dominant inheritance.…”

“…For initial analysis, as reference we included genotypes, publicly available in HapMap (http://hapmap.ncbi.nlm.nih.gov/), from Europeans (CEU: Utah residents with Northern and Western European ancestry from the Centre d'Étude du Polymorphisme Humain collection and TSI: Tuscan in Italy), American Indian–Europeans (MEX: Mexican ancestry in Los Angeles, California), West Africans (YRI: Yoruban in Ibadan, Nigeria), and Asians (CHB: Han Chinese in Beijing, China and JPT: Japanese in Tokyo, Japan). In addition, we included genotypes from 80 American Indian individuals (Nahuas) from Ocotitlán, Mexico (25) who were genotyped using the Illumina HumanOmni1‐Quad version 1 BeadChip Kit and who were known to have been in relative isolation.…”

Clinical heterogeneity of recessive ataxia in the Mexican population

“…14 The 120 patients without FXN mutations were further screened and found not to have mutations in Abbreviations: AOA, ataxia with oculomotor apraxia; FRDA, Friedreich ataxia; FXN, frataxin gene; ILOCA, idiopathic late-onset cerebellar ataxia; MSA, multiple-system atrophy the aprataxin gene (by single-strand conformational polymorphism screening), or expansions in the genes responsible for spinocerebellar ataxias (SCA1, SCA2, SCA3/MJD, SCA6, SCA7, SCA8, SCA10, SCA12 or SCA17). a-Tocopherol and ctocopherol levels ruled out vitamin E deficiency, and normal lipid profiles and ophthalmological examination excluded the possibility of abetalipoproteinaemia.…”

“…We therefore analysed a cohort of 134 patients with recessive or sporadic progressive ataxia from the Mexican Mestizo (mixed) population for genetic and non-genetic causes of ataxia. Among those who tested negative for FXN gene mutations, 14 we identified several patients who fulfilled the clinical criteria for FRDA. On analysing the clinical features of patients without the clinical or genotypic characteristics of FRDA, we identified a phenotypic subgroup of patients with early-onset recessive ataxia with frequent cognitive deficit.…”