A Japanese Patient with a 2p25.3 Terminal Deletion Presented with Early‐onset Obesity, Intellectual Disability and Diabetes Mellitus: A Case Report

2p25.3 deletion syndrome is a rare genetic disorder that accompanies various phenotypic features, including early-onset obesity and intellectual disability. Here, we report the first Japanese case of this deletion associated with severe obesity and diabetes mellitus. Microarray-based comparative genomic hybridization analysis identified a 3.1-Mb deletion of distal chromosome band 2p25.3, which was suspected as de novo. The patient also presented bilateral cataracts and adolescent-onset muscular weakness of the upper limbs, both of which were uncommon in previously reported cases. It is possible that these symptoms are also important clinical features suggestive of this syndrome.