2p15p16.1 Microdeletion Syndrome

2p15p16.1 microdeletion syndrome is a recently described syndrome characterized by developmental delay and facial dysmorphism.

Epidemiology

It has been clinically and molecularly characterized in 5 patients.

Clinical description

Dysmorphic features include receding forehead, telecanthus, epicanthic fold, short and down-slanting palpebral fissures, ptosis, broad and high nasal bridge, retrognathia, flat philtrum, small mouth with high, narrow palate and everted lower lip. Ophthalmologic examination in 4 patients revealed bilateral optic atrophy/hypoplasia. Microcephaly, short stature, genitourinary abnormalities and behavioral problems are common.

Etiology

This syndrome is caused by an interstitial deletion 2p15p16.1 (present in mosaic in one patient). These de novo deletions were characterized by comparative genomic hybridisation (CGH) microarray and fluorescence in situ hybridization (FISH). They have a variable size from 570 kb to 5.7 Mb and encompass several genes. Haploinsufficiency of these genes could contribute to the phenotype.