Alveolar capillary dysplasia with antenatal anomalies mimicking trisomy 21

Alveolar capillary dysplasia (ACD) has been described in conjunction with a number of congenital abnormalities. The case reported here was noted in ut ero to have duodenal atresia and a partial atrioventricular canal defect an d a provisional diagnosis of trisomy 21 was considered. A fetal blood sampl e showed a normal karyotype. The diagnosis of ACD was made at post-mortem f ollowing a neonatal death on the tenth day. This case further highlights th e range of congenital abnormalities that may be present in cases of ACD tha t may mimic other conditions, including trisomy 21, on antenatal scan. Howe ver, the absence of congenital anomalies, even in the same family, would no t exclude the diagnosis of ACD.