Bilateral agenesis/aplasia of the lungs: report of a second case in the offspring of one woman.

Congenital absence of both lungs is an extremely rare malformation in humans and is thought to occur sporadically. We report the second case of congenital absence of both lungs in the offspring of one woman. In neither case, one female baby (born at term) and one aborted female fetus (21 weeks of gestation), were anomalies or malformations of other organ systems observed. The karyotype of the aborted fetus was 46,XX. To our knowledge, this is the first report describing bilateral pulmonary agenesis in two offspring of one mother. The repetition of virtually the same isolated abnormality with no other malformations supports the hypothesis that it could be caused by a genetic disorder. Other etiologies previously suggested, such as drugs or viruses, cannot be excluded but seem less likely.