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Candidate Gene Testing in Clinical Cohort Studies with Multiplexed Genotyping and Mass Spectrometry
Published on: June 21, 2018
Biallelic and triallelic approaches of 5-HTTLPR polymorphism are associated with food intake and nutritional status
Raquel C K Miranda1, Júlia P Genro2, Paula D B Campagnolo3
1Laboratório de Biologia Molecular, Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre, Rua Sarmento Leite, 245/Anexo 3 sala 303; CEP 90050-170, Porto Alegre, RS, Brazil.
Background:
The 5-HTT gene contains polymorphisms in its promoter region, the insertion/deletion (5-HTTLPR) that creates long (L) or short (S) alleles (biallelic approach) and SNP (rs25531) in L allele (triallelic approach).
Objectives:
The aim of this study is to investigate the association of the 5-HTTLPR and rs25531 polymorphisms, using bi- and triallelic approach, with dietary intake and anthropometric parameters in children followed until 8 years old.
Methods:
The sample were 303 children who were recruited at birth and examined at 1, 3 to 4 and 7 to 8 years old. The polymorphisms were analyzed by polymerase-chain-reaction-based methods.
Results:
In the biallelic approach, children with the S/S genotype presented a higher body mass index Z-score in the three developmental stages and higher sum of skinfolds at 3 to 4 and 7 to 8 years old than carriers of the L allele. In the triallelic approach, S/S, Lg/S plus Lg/Lg genotypes were associated with higher energy intake daily at 1 year old and with waist circumference at 3 to 4 years old.
Conclusions:
In the biallelic approach, the 5-HTTLPR polymorphism is associated with food intake, body mass index Z-score and sum of skinfolds in children, reinforcing the role of the serotonin transporter in childhood obesity. Our data indicate that the biallelic approach is more sensible than the triallelic approach for detected associations with food intake and nutritional status in childhood. Identifying susceptibility genes in early life could provide the foundations for interventions in lifestyle to prevent children to become obese adults.
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