[Association of FTO gene polymorphisms and morbid obesity in the population of Extremadura (Spain)].
OBJECTIVE
To select individuals whose morbid obesity can be attributed mainly to their individual genetic profile. After excluding patients with potential monogenic syndromes or diseases associated with obesity, we evaluated the association of the single nucleotide polymorphisms (SNPs) rs1861868 and rs9939609 of the fat-mass and obesity-associated FTO gene with an inherited predisposition to morbid obesity.


METHODS
We evaluated 270 patients with morbid obesity and onset before the age of 14 years and selected 194 due to their phenotypes and family history; 289 control individuals were included. The rs1861868 and rs9939609 variants, located in the FTO gene, were genotyped. Genotype and haplotype frequencies were compared between cases and controls.


RESULTS
The A allele of rs9939609 was associated with severe obesity starting in childhood among the Spanish population. The rs1861868 G/rs9939609 A haplotype of the FTO gene was also significantly associated with severe obesity in our population, with an odds ratio of 3.03 (95% confidence interval, 1.74-5.27).


CONCLUSIONS
Analysis of the genetic basis of obesity requires rigorous selection of cases. In this study, the association of the rs9939609 SNP with obesity widely described in distinct populations was confirmed among overweight Spanish children. Genotyping rs1861868 allowed us to identify the first risk haplotype in the FTO gene, which is located in the adjacent haplotype block containing rs9939609. In-depth study of the variability of the FTO gene is essential to define its deleterious capacity.
Rodríguez-López
Raquel
R
Unidad de Genética, Servicio de Inmunología y Genética, Complejo Hospitalario Universitario de Badajoz, Badajoz, Spain. raquel.rodriguezl@ses.juntaextremadura.net
González-Carpio
Marta
M
Serrano
M Victoria
MV
Torres
Guadalupe
G
García de Cáceres
M Teresa
MT
Herrera
Trinidad
T
Román
Angel
A
Rubio
Marta
M
Méndez
Pilar
P
Hernández-Sáez
Rosario
R
Núñez
Manuela
M
Luengo
Luis M
LM
D000293:Adolescent; D000328:Adult; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000235:genetics*; D011110:Polymorphism, Genetic; D011506:Proteins / Q000235:genetics; D013030:Spain; D055815:Young Adult
D011506:Proteins; D000071516:Alpha-Ketoglutarate-Dependent Dioxygenase FTO; C526492:FTO protein, human