Familial spontaneous pneumothorax-report of seven cases in two families.

Spontaneous pneumothorax usually occurs sporadically in healthy young adults, who tend to be tall and thin. The usual cause is rupture of small subpleural bullae found in the apex of the upper lobe. Familial spontaneous pneumothorax is a rare condition. With a review of the English literature from 1921 to 1991, only 59 families with 135 cases have been reported. A genetic background has been suggested, but the actual mode of inheritance is still unknown. Relationships between the HLA haplotype A2B40, the alpha1-antitrypsin phenotype and the occurrence of spontaneous pneumothorax have been proposed, but are still controversial. We present 7 patients in 2 families with 13 episodes of spontaneous pneumothorax. Neither congenital defect, alpha1-antitrypsin deficiency nor the described A2B40 HLA haplotype could be found in our patients. We propose that there are no such factors existed in these patients. Further study is required to determine if any genetic marker is linked to familial spontaneous pneumothorax.