OBJECTIVES - Familial partial lipodystrophy, Dunnigan variety (FPLD), is an autosomal dominant disorder due to missense mutations in the lamin A/C (LMNA) gene encoding nuclear lamina proteins. It is characterized by loss of subcutaneous fat from the extremities and trunk and accumulation of fat in the head and neck region beginning at puberty. Patients with FPLD are predisposed to metabolic complications of insulin resistance such as diabetes. We sought to identify risk factors for diabetes in patients with FPLD. RESEARCH DESIGN AND METHODS - A cross-sectional study comparing clinical, biochemical, and anthropometric variables and LMNA genotypes in FPLD patients with and without diabetes. RESULTS - We studied 52 women and 24 men with FPLD from 18 different families. Twenty-eight women (54%) but only four men (17%) had diabetes (P < 0.001); therefore further comparisons were mostly limited to women. Compared with women without diabetes, those with diabetes had higher BMI (median values 23 vs. 24 kg/m2, respectively; P = 0.03), increased chin skinfold thickness (10 vs. 20 mm; P = 0.001), lower rates of nulliparity (60% vs. 28%; P = 0.04), and higher levels of fasting serum triglycerides (2.4 vs. 3.5 mmol/l; P < 0.001) but similar serum leptin levels (3.4 vs. 3.6 ng/ml; P = 0.9). The prevalence of diabetes was not related to age, menopausal status, family history of type 2 diabetes in unaffected relatives, or LMNA genotype. CONCLUSIONS - We conclude that increased adiposity as reflected by excess subcutaneous fat accumulation in the chin region and parity may predispose women with FPLD to develop diabetes.