Two autopsy cases of siblings with alveolar capillary dysplasia: clinical and post-mortem issues

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare but fatal lung disorder, which causes persistent pulmonary hypertension of the newborn (PPHN) and which is unresponsive to treatment. We report the case of two siblings, both of whom died a few hours after birth because of severe pulmonary failure. Post-mortem histology confirmed ACD/MPV as the cause of death in both cases, and genetic analysis identified the same 16p13.3 deletion. ACD/MPV can occur suddenly in apparently healthy newborns after a regular pregnancy, and always leads to death. Nevertheless, an autopsy is not always performed after the death of an infant. For these reasons ACD/MPV represents a challenge for diagnosis and therapeutic management with medicolegal implications. Prenatal assessment of ACD/MPV is very difficult, and it should be suspected when irreversible and persistent fetal circulation occurs rapidly in newborns. An early diagnosis during pregnancy would facilitate adequate counselling regarding treatment and prognosis. When death occurs, a complete autopsy with histological and genetic investigations is recommended in order to define the exact cause of death, and potentially inform appropriate genetic counselling of family members who could be affected by hereditary disorders.