Distal del(4) (q33) syndrome: detailed clinical presentation and molecular description with array-CGH.

The 4q deletion syndrome, comprising all microscopically visible deletions (interstitial and terminal) is a well-recognized distinctive malformation entity, with an estimated incidence of 1:10,000. Here we present the clinical and molecular findings in a 3-year-old male with a de novo distal deletion of 4q33 [46,XY,del(4) (q33)]. Clinical findings of the patient include: hypertelorism, broad nasal bridge, short nose with anteverted nares, long philtrum, thin upper lip, micro-retrognathia, low-set and protruding ears, pre-auricular tag unilaterally, low posterior hairline, clinodactyly of the 5th fingers, tapering fingers, hypospadias, and severe psychomotor retardation. Soon after birth he developed severe hypotonia and feeding difficulties. Echocardiography at 15 months documented aortic supravalvular membrane resulting in mild aortic stenosis and dysplasia of the pulmonary valve. Genome-wide screening using 1 Mb resolution array-CGH and subsequent FISH analyses defined a 18.9-22.9 Mb deletion located at the beginning of 4q33 and extending to the telomere. The description of additional cases with similar distal deletions of 4q33 will allow a more precise prognosis and is therefore of great value for genetic counsellors, while detailed molecular characterization in any well clinically characterized patient is expected to track down individual candidate genes for the specific features of the syndrome.