1. Second Department of Internal Medicine, Chiba University School of Medicine, Inohana, Chiba 280, Japan.
2. Department of Biochemistry, Chiba University School of Medicine, Inohana, Chiba 280, Japan.
3. Department of Pediatrics, Shimoshizu National Hospital and Sanatorium, Yotsukaido, Chiba 284, Japan.
4. Department of Enzyme Genetics, Institute for Enzyme Research, University of Tokushima, Kuramotocho, Tokushima 770, Japan.