Hypospadias, when the urethra opens on the ventral side of the penis, is a 
common malformation seen in about 3 per 1,000 male births. It is a complex 
disorder associated with genetic and environmental factors and can be part of 
genetic syndromes. Mowat-Wilson syndrome (MWS) is a multiple congenital anomaly 
syndrome characterized by a distinct facial phenotype, Hirschsprung disease, 
microcephaly and mental retardation. It is caused by mutations in the zinc 
finger homeo box 1B gene, ZFHX1B (SIP1). To date, 68 deletion/mutation-positive 
cases have been reported. Genitourinary anomalies are common in MWS. Here we 
report that hypospadias is common in males with this syndrome. In 39 patients 
where this information was available, hypospadias was present in 46% of patients 
(18/39). In the 3 Italian male cases reported here, hypospadias was always 
present. MWS should be considered by endocrinologists in patients with 
hypospadias associated with developmental delays/mental retardation, in 
particular in the presence of a distinct facial phenotype.