[Alpha 1-antitrypsin deficiency (Siiyama) with pulmonary emphysema].

: A 44-year-old man was admitted to the hospital with dyspnea on exertion. Chest radiographs and pulmonary function tests showed evidence of pulmonary emphysema. Serum alpha 1-antitrypsin (alpha 1-AT) could not be detected by nephelometry, immuno-electrophoresis, or iso-electric focusing. However, allele-specific PCR revealed a genotype homozygotic for an alpha 1-AT deficient variant of the Siiyama allele. An elder sister of the proband was also a homozygous carrier of the Siiyama allele. The amino acid sequence for normal alpha 1-AT variants had been substituted by Arg101-Val213-Glu376 in the proband, demonstrating that the alpha 1-antitrypsin-deficient Siiyama variant in this pedigree was derived from M 1 (Val213).