Prenatal diagnosis of cri-du-chat syndrome: importance of ultrasonographical markers.

Cri-du-chat syndrome is a chromosomal abnormality involving a 5p deletion and is characterised by a cat-like cry, mental retardation, microcephaly and abnormal facial features. We report a case of prenatally-diagnosed cri-du-chat syndrome. Although PAPP-A was low at first trimester screening (FTS), the combined risks of trisomies 21, 18 and 13 were low. Amniocentesis was, however, carried out following the ultrasonographical observation of a severely hypoplastic nasal bone, cerebellar hypoplasia, choroid plexus cyst and a single umbilical artery during the second trimester. This case report highlights the importance of careful examination of basic and extended foetal biometry and structures, as well as soft markers for the detection of rarer chromosomal abnormalities that may be missed at FTS.