Novel BRPF1 mutation in a boy with intellectual disability, coloboma, facial nerve palsy and hypoplasia of the corpus callosum

Abstract

Mutations in the chromatin regulator gene BRPF1 were recently associated with the Intellectual Developmental Disorder With Dysmorphic Facies And Ptosis (IDDDFP). Up till now, clinical data of 22 patients are reported. Besides intellectual disability (ID), ptosis and blepharophimosis are frequent findings, with refraction problems, amblyopia and strabism as other reported ophthalmological features. Animal studies indicate BRPF1 as an important mediator in brain development. However, only 5 of 22 previously reported patients show structural brain abnormalities. We report on an additional patient harboring a novel de novo nonsense mutation p.(Glu219*) in BRPF1. He presented with ID, bilateral iris colobomas, facial nerve palsy and severe hypoplasia of the corpus callosum. Our findings support previous findings of brain abnormalities in BRPF1-mutations and indicates coloboma and facial nerve palsy as possible additional features of IDDDFP syndrome.

Keywords: BRPF1; Coloboma; Corpus callosum hypoplasia; Facial nerve palsy; Intellectual disability.