Novel splice-site mutation in WDR62 revealed by whole-exome sequencing in a Sudanese family with primary microcephaly.

The WDR62 gene encodes a scaffold protein of the c-Jun N-terminal kinase (JNK) pathway. It plays a critical role in laying out various cellular layers in the cerebral cortex during embryogenesis, and hence the dramatic clinical features resulting from WDR62 mutations. These mutations are associated with autosomal recessive primary microcephaly 2, with or without cortical malformations (MCPH2). Using whole exome sequencing we uncovered a novel WDR62 variant; c.390G > A, from two Sudanese siblings whose parents are first cousins. The patients suffered MCPH2 with incomplete lissencephaly and developmental delay. The mutation affects the last nucleotide of exon4, and probably leads to aberrant splicing, which may result in a truncated protein lacking all functional domains.