VNTR (CAG)n polymorphism of the ATXN2 gene and metabolic parameters of cardiovascular risk associated with the degree of obesity in the Amerindian population of Oaxaca.

INTRODUCTION: The ATXN2 gene has a VNTR (CAG)n with locus in exon1. Long alleles within the normal range (22-29 repeats) are associated with severe obesity in people from the United Kingdom, Indonesia and the Caribbean. OBJECTIVE: To analyse the influence of VNTR (CAG)n on metabolic profile in adults with obesity and pre-obesity, as well as to estimate its effect on the risk of developing diabetes. METHODS AND MATERIAL: 255 adults of Chinantec Amerindian ethnic origin were included, who underwent anthropometric and biochemical evaluation. The VNTR was amplified by end-point PCR and by 8% PAGE electrophoresis. RESULTS: Differences were found in the waist/hip circumference index and body mass index in the carriers of genotypes different to the one homozygous for 22 repeats with a Student's t-test value of 0.0041 and 0.0334, respectively. We also found an association with a family history of chronic disease. CONCLUSION: The VNTR of ATXN2 is associated with obesity in Mexican adults of Chinantec ancestry.

VNTR (CAG)n polymorphism of the ATXN2 gene and metabolic parameters of cardiovascular risk associated with the degree of obesity in the Amerindian population of Oaxaca. / Polimorfismo VNTR (CAG)n del gen ATXN2 y parámetros metabólicos de riesgo cardiovascular asociados con el grado de obesidad en población amerindia de Oaxaca.

INTRODUCTION: The ATXN2 gene has a VNTR (CAG)n with locus in exon1. Long alleles within the normal range (22-29 repeats) are associated with severe obesity in people from the United Kingdom, Indonesia and the Caribbean. OBJECTIVE: To analyse the influence of VNTR (CAG)n on metabolic profile in adults with obesity and pre-obesity, as well as to estimate its effect on the risk of developing diabetes. METHODS AND MATERIAL: 255 adults of Chinantec Amerindian ethnic origin were included, who underwent anthropometric and biochemical evaluation. The VNTR was amplified by end-point PCR and by 8% PAGE electrophoresis. RESULTS: Differences were found in the waist/hip circumference index and body mass index in the carriers of genotypes different to the one homozygous for 22 repeats with a Student's t test value of 0.0041 and 0.0334, respectively. We also found an association with a family history of chronic disease. CONCLUSION: The VNTR of ATXN2 is associated with obesity in Mexican adults of Chinantec ancestry.

Association between nutritional risk markers and polymorphisms rs2291166 in TJP1 and VNTR (CAG)n in ATXN2 in an obese adolescent Mexican population. / Asociación entre marcadores de riesgo nutricionales con los polimorfismos rs2291166 de TJP1 y el VNTR (CAG)n de ATXN2 en población mexicana adolescente con obesidad.

OBJECTIVE: To estimate the correlation between indices of diet quality (DQIs), insulin sensitivity (QUICKI) and resistance (HOMA-IR), waist circumference (WHR) and body mass (BMI) and the alleles and genotypes of the TJP1 SNP rs2291166 and the VNTR of ATXN2 in adolescent patients. SUBJECTS AND METHOD: The study enrolled 85 subjects aged 10-20years, from the city of Tuxtepec, Oaxaca, Mexico, recruited in the period 2017-2018. DQIs, BMI, WHR, HOMA-IR, QUICKI, and diet quality index were measured. The rs2291166 polymorphism in TJP1 was determined by allele-specific PCR and the (CAG)n expansion in ATXN2 was determined by hot start PCR. PCR products were analyzed using 8% PAGE electrophoresis and silver nitrate staining. RESULTS: A correlation was found of indices DQIs, HOMA-IR, WHR and BMI with the heterozygous genotype of the TJP1 SNP rs2291166 and the long and short repeats of the ATXN2 CAG repeat in obese adolescent patients. A very strong positive correlation was seen between the TJP1 SNP and the HOMA-IR index (P<.05). A positive correlation was also found between the ATXN2 CAG repeat and the QUICKI index (P=.000) (P<.05), while the DQIs index correlated more closely with BMI and WHR. CONCLUSIONS: DQIs, TJP1 SNP rs2291166, and ATXN2 CAG repeat are determinants of obesity-related risk parameters such as BMI, WHR, QUICKI, and HOMA-IR in the adolescent population analyzed.