6q25 Microdeletion Syndrome

6q25 microdeletion syndrome is a recently described syndrome characterized by developmental delay, facial dysmorphism and hearing loss.

Epidemiology

It has been clinically and molecularly characterized in 4 patients.

Clinical description

All of them presented with microcephaly, developmental delay, dysmorphic features and hearing loss, whereas two of them had agenesis of the corpus callosum. Dysmorphic features include midface hypoplasia, hypertelorism, broad nasal root and posteriorly rotated ears.

Etiology

This syndrome is caused by an interstitial deletion encompassing 6q25.2-q25.3. These de novo deletions were characterized by comparative genomic hybridization (CGH) microarray and fluorescence in situ hybridization (FISH). They have a variable size with the smallest region of overlap (SRO) of 3.52 Mb.