Maternal leptin receptor gene variant Gln223Arg is not associated with variation in birth weight or maternal body mass index in UK and South Asian populations

BACKGROUND: Leptin is an adipocyte secreted hormone involved in regulation of body weight and metabolism in man. Placenta leptin levels correlate positively with birth weight. It is therefore possible that variation in the leptin receptor gene (LEPR) may contribute to obesity and influence birth weight. OBJECTIVE: This study investigates the influence of the leptin receptor gene variant Gln223Arg (A-->G, 668), on maternal body mass index (BMI), foetal gestational length and birth weight in a cohort of 455 healthy pregnant women of Asian Indian (India, Bangladesh, Pakistan) and UK/Irish origin. RESULTS: Maternal genotype distributions did not differ from those expected under Hardy-Weinberg equilibrium conditions in either population of origin. Maternal genotype for the Gln223Arg leptin receptor gene polymorphism showed no significant association with foetal birth weight (adjusted for gestational length) or with maternal BMI during first trimester (adjusted for age) in either population group. CONCLUSION: These results suggest that the Gln223Arg variant in the maternal leptin receptor gene does not explain the association between placental leptin levels and birth weight, and is not associated with variation in maternal BMI in early pregnancy in our sample.