Alveolar capillary dysplasia with misalignment of pulmonary veins is an increasingly recognized cause of persistent pulmonary hypertension in the newborn. Although initially seen only at autopsy, there are now many examples of lung biopsy in young infants in whom this developmental abnormality has been recognized. Affected infants are usually term or near term, and they present with persistent pulmonary hypertension in the first few postnatal days. Although they may initially respond to therapeutic measures, a sustained response is never achieved and most die before they are 1 month old. There are many exceptions, however, with later presentations and longer survival, but all eventually succumb to pulmonary hypertension or its complications. There have been a number of familial cases with affected sibling pairs, indicating that, at least in some families, this condition is likely to be autosomal recessive in nature. Many affected infants have abnormalities of other organ systems, predominantly the heart and gastrointestinal and genitourinary tracts. Several limb abnormalities have also been described. No consistent pattern of associated malformation has been identified. The genetic abnormality of this unusual condition has yet to be identified. This uniformly lethal condition may be amenable to treatment by lung transplantation, but none has been reported.

Although it has been suggested that alveolar capillary dysplasia can occur without misalignment of pulmonary veins, such cases more likely represent other conditions modified by prolonged supportive measures and not this developmental abnormality.