Deleterious, protein-altering variants in the transcriptional coregulator ZMYM3 in 27 individuals with a neurodevelopmental delay phenotype.

Neurodevelopmental disorders (NDDs) result from highly penetrant variation in hundreds of different genes, some of which have not yet been identified. Using the MatchMaker Exchange, we assembled a cohort of 27 individuals with rare, protein-altering variation in the transcriptional coregulator ZMYM3, located on the X chromosome. Most (n = 24) individuals were males, 17 of which have a maternally inherited variant; six individuals (4 male, 2 female) harbor de novo variants. Overlapping features included developmental delay, intellectual disability, behavioral abnormalities, and a specific facial gestalt in a subset of males. Variants in almost all individuals (n = 26) are missense, including six that recurrently affect two residues. Four unrelated probands were identified with inherited variation affecting Arg441, a site at which variation has been previously seen in NDD-affected siblings, and two individuals have de novo variation resulting in p.Arg1294Cys (c.3880C>T). All variants affect evolutionarily conserved sites, and most are predicted to damage protein structure or function. ZMYM3 is relatively intolerant to variation in the general population, is widely expressed across human tissues, and encodes a component of the KDM1A-RCOR1 chromatin-modifying complex. ChIP-seq experiments on one variant, p.Arg1274Trp, indicate dramatically reduced genomic occupancy, supporting a hypomorphic effect. While we are unable to perform statistical evaluations to definitively support a causative role for variation in ZMYM3, the totality of the evidence, including 27 affected individuals, recurrent variation at two codons, overlapping phenotypic features, protein-modeling data, evolutionary constraint, and experimentally confirmed functional effects strongly support ZMYM3 as an NDD-associated gene.

Wilson Disease: A Case Report of Psychosis Preceding Parkinsonism.

BACKGROUND A first psychotic episode requires the exclusion of toxic-metabolic, inflammatory, infective, and neoplastic causes. Wilson disease is a rare, autosomal recessive disorder of copper metabolism and can present with neuropsychiatric symptoms secondary to copper accumulation in the brain. CASE REPORT We describe the case of a 48-year-old man with parkinsonism on a background of longstanding schizophrenia and psychotic depression in the setting of previously undiagnosed Wilson disease. The common history of neuropsychiatric disturbance and neuroleptic use complicated the assessment of parkinsonism. However, close attention to the temporal appearance of symptoms and signs differentiated his case from drug-induced parkinsonism, which commonly develops hours to weeks after commencement or uptitration of antipsychotic medication. The early features of sialorrhea and dysarthria were also atypical for idiopathic Parkinson disease. The diagnosis was confirmed by serum copper testing and supported by Kayser-Fleischer rings on bedside ophthalmological examination. Magnetic resonance imaging (MRI) of the brain demonstrated copper accumulation in the basal ganglia and pons, contributing to the characteristic neurological manifestations of an akinetic-rigid syndrome with dysarthria. CONCLUSIONS Serum copper testing is easily obtained and should be considered as part of the first-line investigations for new neuropsychiatric disturbances. Although rare, Wilson disease, if diagnosed early, is a potentially treatable and reversible cause of psychosis. With advanced disease, extrapyramidal findings on examination correlate with MRI brain changes, aiding the clinical assessment in differentiating the disease from drug-induced parkinsonism.