4q21 Microdeletion Syndrome

The 4q21 microdeletion syndrome is a newly described syndrome associated with facial dysmorphism, progressive growth restriction, severe intellectual deficit and absent or severely delayed speech.

Epidemiology

It has been reported in nine unrelated patients.

Clinical description

The most common facial feature includes high or broad forehead, hypertelorism and short philtrum. Short hands and feet are frequently observed.

Etiology

This microdeletion was identified by comparative genomic hybridisation (CGH) microarray. The critical region encompasses two candidate genes, PRKG2 and RASGEF1B, in which haploinsufficiency could participate to the phenotype.