P118 – 2595: Chromosomal 5p13 duplication associated with periventricular white matter abnormality and septum pellucidum variant

Abstract

Objective Chromosomal 5p13 duplication (OMIM #613174) is a rare contiguous gene syndrome involving duplication of several genes on chromosome 5p13. Clinical features of the syndrome include developmental delay, intellectual disability, behavioural impairment, microcephaly or macrocephaly, and facial dysmorphism (frontal bossing, large/broad forehead, bitemporal narrowing, short or slanted palpebral fissures, short philtrum, high-arched palate, and low set ears). One reported patient had agenesis of the corpus callosum. We aim to describe the case of a 2 years old girl with chromosomal 5p13 duplication in order to characterise clinical features and additional neuroradiological features. Methods Case and neuroimaging review. Results 2 years old girl with periventricular white matter changes and absence of posterior portion of the septum pellucidum on MR imaging in whom a chromosomal 5p13 duplication was identified by array-based comparative genomic hybridization (CGH). Extensive neurometabolic investigations were normal. Our case describes some of the previous clinical features associated with chromosomal 5p13 duplication syndrome while expanding its clinical spectrum with additional neuroradiological features. No abnormalities in white matter were described in previously reported patients with chromosomal 5p13 duplication. Conclusion Genome-wide studies such as arrays CGH should be considered in the assessment of non-specific white matter and structural abnormalities or variant. The etiology of the white matter abnormalities in chromosomal 5p13 duplication is unknown, but may represent either dysmyelination or delayed myelination.