Editor—Pulmonary agenesis is an extremely rare congenital malformation which has been classified morphologically by the extent to which bronchopulmonary tissue is absent. Spencer1 divided pulmonary agenesis into (1) bilateral complete agenesis, (2) unilateral agenesis with (a) complete absence of bronchi, (b) rudimentary bronchus present but no pulmonary tissue, or (c) poorly developed main bronchus with poorly organised parenchyma, and (3) lobar agenesis. The incidence of this rare condition is not known. According to the calculations of Mardini and Nyhan2it may range between 0.0034 and 0.0097%. Familial pulmonary agenesis is even more uncommon. We found only two published reports of affected sibs.3 4 One pair of sibs had agenesis of the right upper and middle lobes3 and the other pair suffered from bilateral agenesis.4

The paucity of such observations prompts us to report another instance of pulmonary agenesis in a brother and a sister of healthy and non-consanguineous parents. The family history was unremarkable and both pregnancies were uneventful. The mother had no infections and denied any abuse of teratogenic substances. Chromosomes were not studied in either case.

The first child, a female, was delivered spontaneously at term with a birth weight of 3500 g. Birth length and head circumference were not recorded. The mother was 27 years old and the father 36 years old. At the age of 11 months she was admitted to hospital because of stridor and dyspnoea. The interpretation of the chestx ray was spontaneous pneumothorax on the left side with dextrocardia and compression atelectasis of the right upper lobe. Over the following years, she suffered from asthmatic bronchitis secondary to recurrent infections. Psychomotor development was within the normal range. Pulmonary re-evaluation …