Congenital generalized lipodystrophy type 4 with muscular dystrophy: clinical and pathological manifestations in early childhood.

A boy with congenital generalized lipodystrophy type 4 with muscular dystrophy presented in infancy with delay in motor milestones and a persistent elevation of CK. There was no associated mental retardation. He was followed up to 3 years and 11 months; he had a homozygous c.696_697insC mutation in polymerase I and transcript release factor (PTRF). He started to walk at 2 years and 6 months although he did not have mental retardation. Insulin resistance appeared at 3 years and 11 months of age. PTRF immunostaining positivity was absent in the muscle but caveolin-3 was preserved in the sarcolemma at 16 months of age. Secondary deficiency of caveolins may be closely associated with disease progression.