Toshiyuki Yamamoto    Department   School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine    Position   Professor
Article types	Original article
Language	English
Peer review	Non peer reviewed
Title	A new microdeletion syndrome of 5q31.3 characterized by severe developmental delays, distinctive facial features, and delayed myelination.
Journal	Formal name：American Journal of Medical Genetics
Volume, Issue, Page	155A(4),pp.732-736
Author and coauthor	Keiko Shimojima, Bertrand Isidor, Cedric Le Caignec, Akiko Kondo, Shinji Sakata, Kousaku Ohno, Toshiyuki Yamamoto
Publication date	2011/04
Summary	Chromosomal deletion including 5q31 is rare and only a few patients have been reported to date. We report here on the first two patients with a submicroscopic deletion of 5q31.3 identified by microarray-based comparative genomic hybridization. The common clinical features of both patients were marked hypotonia, feeding difficulty in infancy, severe developmental delay, and epileptic/nonepileptic encephalopathy associated with delayed myelination. Both patients also shared characteristic facial features, including narrow forehead, low-set and abnormal auricles, bilateral ptosis, anteverted nares, long philtrum, tented upper vermilion, edematous cheeks, and high palate. The deleted region contains clustered PCDHs, including PCDHA and PCDHG, which are highly expressed in the brain where they function to guide neurons during brain development, neuronal differentiation, and synaptogenesis. The common deletion also contains neuregulin 2 (NRG2), a major gene for neurodevelopment. We suggest that 5q31.3 deletion is responsible for severe brain developmental delay and distinctive facial features, and that the common findings in these two patients representing a new microdeletion syndrome. We need further investigations to determine which genes are responsible for the patients' characteristic features.
DOI	10.1002