A 56-year-old male with severe α1-antitrypsin deficiency and four cases in his family are reported. The patient (propositus) was admitted because of dyspnea. X-ray films of the chest disclosed marked emphysema. Respiratory examinations revealed increase of residual volume/total lung capacity ratio and forced expiratory volume, and decrease of CO diffusion.
Cellulose acetate electrophoresis revealed decrease of α1-fraction. Serum α1-antitrypsin was 10 mg/dl by single radial immunodiffusion. Trypsin inhibitory capacity also markedly decreased. Immunoelectrophoresis showed no precipitin line of α1-antitrypsin developed with anti-α1-antitrypsin.
The α1-antitrypsin phenotype of the patient was designated as a variant of PiM, PiMnumazu, by cellulose acetate isoelectric focusing followed by crossed immunoelectrophoresis, which was more sensitive than acid starch gel electrophoresis and useful for distinguishing the genetic variability of α1-antitrypsin deficiency.
Family study revealed that the parents, the youngest brother, one of his uncles and one of his aunts were heterozygous for α1-anititrypsin gene. They had no pulmonary emphysema except for the propositus.
