No abstract

The influence of genetics on human physique and obesity has been addressed by the literature. Evidence for heritability of anthropometric characteristics has been previously described, mainly for the body mass index (BMI). However, few studies have investigated the influence of genetics on the Heath-Carter somatotype. The aim of the present study was to assess the heritability of BMI and somatotype (endomorphy, mesomorphy, and ectomorphy) in a group of female monozygotic and dizygotic twins from childhood to early adulthood. A total of 28 females aged from 7 to 19 years old were studied. The group included 5 monozygotic and 9 dizygotic pairs of twins. The heritability was assessed by the twin method (h 2 ). The anthropometric measures and somatotype were assessed using standard validated procedures. Significant differences between monozygotic and dizygotic pairs of twins were found for height, endomorphy, ectomorphy, and mesomorphy, and the heritability for these measures was high (h 2 between 0.88 and 0.97). No significant differences were found between monozygotic and dizygotic twins for weight, and the BMI and the heritability indexes were lower for these measures (respectively 0.42 and 0.52). The results of the present study have indicated that the somatotype may be more sensible to genetic influences than the BMI in females.

The genetic and environmental contributions to determine digital dermatoglyphic traits were investigated by using female dizygotic and monozygotic twin pairs to estimate heritability indexes (h2). The evaluated sample was composed by 20 monozygotic twin pairs and 13 dizygotic twin pairs. A significant heritability (h2 = 0.65 to 0.96) was observed for 12 dermatoglyphic characteristics (delta indexes and ridge counts for right hand, left hand and both hands, and ridge counts for most individual fingers). A negative correlation between the ridge counts and heritability indexes from individual fingers was found for the left hand, which appears to be associated to a higher arch pattern frequency in most left-hand fingers, since this frequency was negatively correlated with ridge counts and positively correlated with heritability indexes. Heritability indexes of right-hand fingers were positively correlated with loop pattern frequency and negatively correlated with whorl pattern frequency. The low heritability of ridge counts from left thumb, ring and little fingers (h2 = 0.11 to 0.32) indicates a higher chance that the chorion type had an influence in the intra-pair variance of monozygotic twins. Results confirmed the predominant genetic influence on the total ridge count. The heritability indexes varied in up to 8 times between different fingers and its association to ridge counts and pattern frequency was very variable between hands, evidencing that the use of dermatoglyphic traits from individual fingers as indicators of genetic influences to other human traits should consider this variability.

RESUMO O presente estudo teve o objetivo de comparar o desempenho anaeróbico conforme as configurações genéticas RR, RX e XX da proteína ACNT3 em crianças. Utilizou-se uma metodologia descritiva e comparativa com uma amostra de 111 rapazes praticantes de futebol, com idades entre os 7 e 12 anos. A saliva serviu para extração do DNA e identificação do polimorfismo da ACTN3. Posteriormente realizou-se o teste de corrida de 40 metros para a medida da Potência muscular e o Índice de Fadiga. Com isso, foram estabelecidos os subgrupos: Grupo RR (n= 42); Grupo RX (n= 58); Grupo XX (n= 11). A distribuição normal dos dados foi identificada com o teste de Kolmogorov-Smirnov, sendo a comparação realizada por meio da ANOVA one-way com post hoc de Scheffé. Os valores dos tempos das corridas entre os três grupos foram semelhantes, não ocorrendo diferenças significativas. A maior média de Potência foi encontrada no grupo de configuração genética RR; contudo, não foram verificadas diferenças significativas na Potência muscular e no Índice de Fadiga. Assim, como não foram observadas diferenças significativas na capacidade anaeróbica entre os grupos, conclui-se que na infância não é possível identificar o desempenho para o alto rendimento, utilizando-se testes físicos.