We are requesting additional funding to explore the association between intrauterine phenol exposure and fetal and infant growth and fat accrual during the first year of life as well as to explore how maternal metabolic substrates, such as lipids, free fatty acids, and thyroid hormones may affect fetal growth and infant growth, a unique model to study the early origins of obesity. The gene discussed is TG; the disease is obesity due to melanocortin 4 receptor deficiency.