Does Mutations of DLG3 Gene Causes Mental Motor Retardation in Childhood?Author(s): Huseyin Avni Solgun* and Alper Ozk?l?c
Intellectual Disability (ID), formerly called Mental Retardation (MR) has heterogeneous environmental and genetic causes acting in various phases of pre and postnatal development. Current research has been directed to clarify the genetic base of what was accepted as idiopathic MR. Recently in literature many coding variants have been identified in MR in childhood, identification of non-pathogenic coding variants has so far been possible in only a few cases. In this study, we present two cases with Disc-large homolog 3 (DLG3) gene mutation in which the guanine position at positionc.2267 was found to have adenine. DLG3 is the first mental retardation gene directly linked to glutamate receptor signalling and trafficking, increasingly recognised as a central mechanism in the regulation of synaptic formation and plasticity in brain and cognitive development and known to be associated with X linked MR (XLMR). The second case in our study was diagnosed with atypical autism previously. The relationship between Autism Spectrum Diseases (ASD) and XLMR is still unclear, but we identified DLG3 deletion, which appears to be the cause of mental impairment in this individual who was previously diagnosed with atypical autism. As a result of the whole Exom Sequence Analysis, the mutation detected as homozygous in DLG3 gene is thought to cause the XLMR since the both two patients are male. New studies in the future will strengthen this thesis and enlighten the genetic etiology of MR and ASD in childhood.