Objective To ascertain diagnostic and management issues in a rare case of hydrolethalus syndrome (HS) in an Asian couple.

Case Summary A 31-year-old, P2+1, consanguineous married Pakistani woman in her fourth pregnancy was referred at 20-week gestation after ultrasound finding of bilateral mild ventriculomegaly. After first unaffected pregnancy the second baby had bilateral ventriculomegaly, bilateral hydronephrosis, talipes equinovarus and incomplete closure of foramen ovale. Patient had MTOP at 28-week gestation. The third baby had bilateral ventriculomegaly, left foot talipes and patient opted termination at 21-week gestation. Both babies had normal karyotype. She was seen by clinical geneticist and the pedigree, sonographic and autopsy findings in this case were most consistent with HS, which is a rare autosomal recessive lethal malformation syndrome. Other causes of ventriculomegaly and multiple malformation syndromes were also considered. A confident differential diagnosis is difficult for the geneticist in the absence of knowledge of the molecular basis of these disorders. For technical limitations the sonologist faces even more difficulty in diagnosis.

Conclusion As the authors recognise the diagnostic difficulty it is important to know the inheritance pattern and to diagnose the presence and absence of the different manifestations and their severity to provide multidisciplinary care/counselling.