Height less than 2 SDS, diagnosis of T1DM after 18 years of age, evidence of diabetic retinopathy, neuropathy of nephropathy; intake medications, hormones, vitamins, or calcium in the preceding 6 months aside from insulin or thyroid hormones, no chronic disease, no hospitalization or DKA in the preceding months, no restriction of physical activity. The gene discussed is TG; the disease is diabetic retinopathy.