A MORC2 Variant Associated With Severe Intellectual Disability and Unusual Phenotype

ABSTRACT

The microrchidia CW‐type zinc finger protein 2 (MORC2) gene encodes an epigenetic regulator, variants in which are often associated with Charcot–Tooth–Marie (CMT) disease type 2Z. In recent years, notable phenotypic variation has been identified in patients with different MORC2 variants. Here, we present a 61‐year‐old male with a MORC2 c.328C>T, p.(Arg110Cys) variant who displays significant but nonprogressive intellectual disability, hearing loss, retinitis pigmentosa, spasticity, and cerebellar findings, in addition to a mild neuropathy, with follow‐up over 12 years. As the oldest reported patient with this variant and phenotype, this case not only expands the phenotypic spectrum of MORC2‐related disorders but also provides valuable phenotypic information regarding disease progression in later years, particularly regarding the intellectual disabilities associated with MORC2 variants.