Project description:<p>We describe four patients from two unrelated families of different ethnicities who had primary immunodeficiency predominantly manifesting as susceptibility to EBV-related diseases. We performed whole exome sequencing (P1 and P2 from family 1) or whole genome sequencing (P4 and both parents from family 2) in those two families and identified homozygous frameshift or in-frame deletions in CD70 in these patients which abolished either CD70 surface expression or binding to its counter structure CD27. Sanger sequencing identified the same homozygous <i>CD70</i> mutation in P3, which is not included in the dbGaP submission. Autosomal recessive CD70 deficiency is a novel cause of combined immunodeficiency and EBV-associated diseases, reminiscent of CD27 deficiency.</p>
Project description:Non-syndromic mental retardation is one of the most important unresolved problems in genetic health care. Autosomal forms are far more common than X-linked ones, but in contrast to the latter, they are still largely unexplored. Here we report on a complex mutation in the ionotropic glutamate receptor 6 gene (GRIK2, GLUR6), which co-segregates with moderate to severe non-syndromic autosomal recessive mental retardation in a large consanguineous Iranian family1. The predicted gene product lacks the first ligand-binding domain, the two adjacent transmembrane domains and the putative pore-forming loop of the GLUK6 protein, suggesting a complete loss of function, which is supported by electrophysiological data. This finding provides the first irrefutable proof that GLUK6 is indispensable for higher brain functions in man, and future studies of this and other ionotropic kainate receptors will shed more light on the pathophysiology of mental retardation. Keywords: array CGH