CLP1 associated pontocerebellar hypoplasia

Abstract

Pontocerebellar hypoplasia (PCH) is a group of hereditary neurodegenerative diseases characterized by the developmental pathology of infra tentorial brain structures such as cerebellum and pons. In recent years, many new PCH cases have been identified due to the evolution and easily accessible of genetic analysis such as next-generation sequencing. We described a family were referred to our clinic because of epilepsy and MMR in two brothers with dysmorphic features: Physical examination revealed dysmorphic features such as; forehead sloping, hypertelorism, hypertrichosis, indistinct philtrum, cupped right ear, anteverted nares, oligodontia, high-arched palate, short neck, low posterior hairline, pes equinovarus, microcephaly (45cm, <1p (-4.7 SD)).Neurological examination showed evident dystonia in the extremities, increased deep tendon reflexes, spastic tetraparesis. Cranial MRI revealed pontocerebellar hypoplasia . Whole-exome sequence (WES) of two affected brothers revealed a homozygous p.R140H (c.G419A) (chr11:g.57,427,367 G > A [hg19], NM_006831.2) pathogenic variant in the CLP1 gene which were described in 2014 in patients with similar clinical features. In patients with pontocerebellar hypoplasia in MRI, if other causes in the differential diagnosis are ruled out except types and subtypes of PCH and MRI does not show dragon-fly like pattern CLP1 gene can be sequenced first before whole exome or genome sequencing in patients with Asian origin which is much more cheaper and faster.