A new case confirming and expanding the phenotype spectrum of ADAT3-related intellectual disability syndrome.

The present study describes two patients with clinical diagnosis of ID, from a consanguineous family in Israel. Whole exome sequencing identified a homozygous missense mutation in the ADAT3 gene. The clinical features of our patients were compared with several cases described in two recently published studies that documented clinical manifestation of this same mutation. Both affected siblings in our study expressed the previously described clinical features such as intellectual disability, strabismus, FTT/underweight, microcephaly and hypotonia. Interestingly, our patients suffered from additional clinical manifestations that were not detailed in the previous two studies, such as: gait difficulties, instability, teeth abnormalities, neuropathy and contractures of the hand wrist and fingers. We conclude that the ADAT3 gene mutation is responsible for ADAT3-related ID syndrome, which induces the variety clinical manifestations exhibited by our patients. Further studies aimed at identifying and characterizing additional afflicted families worldwide will be required to obtain a more comprehensive understanding of this syndrome.