The most typical features of the disorder caused by PSMC3 mutations include:
• delays in reaching developmental milestones, more especially (i) speech and language, which are delayed or impaired in all patients diagnosed so far; but also (ii) sitting up, crawling and walking;
• intellectual disability (possibly requiring special education);
• facial dysmorphic features (tall or broad forehead, thin upper lip with down-turned corners of mouth, abnormal palate, epicanthal folds, and orofacial clefts);
• brain MRI abnormalities;
• cardiac, renal, skeletal, and genital malformations;
• behavioral problems, namely autism spectrum disorder, irritability, low tolerance to frustration, tantrums, and bipolar disorder;
• hypotonia.
Other common problems could include:
• gastrointestinal issues (feeding difficulties);
• growth failure (underweight, short stature);
• hearing loss
• microcephaly
• Seizures
• ophtalmological concerns (strabismus);
• tumors (craniopharyngioma, neuroblastoma)