Wepreviously reported twosiblings with decreased subcutaneous adipose tissue, muscular atrophy, joint contractures, recurrent skin eruptions, hyper-y-globulinemia, and reduced natural killer cell activity. Some of their clinical features are similar to those of partial lipodystrophy, but they are distinct in that muscular atrophy, joint contractures and recurrent skin eruptions are not found in patients with partial lipodystrophy. Thirteen other Japanese patients with similar clinical manifestations have been reported. Wepropose that such cases should be considered a distinct clinical entity.(Internal Medicine 32: 42-45, 1993)