[Autosomal dominant intellectual developmental disorder 60 with seizures: a case report].

The patient is a 10-month and 21-day-old girl who began to show developmental delays at 3 months of age, with severe language developmental disorders, stereotyped movements, and easily provoked laughter. Physical examination revealed fair skin and a flattened occiput. At 10 months of age, a video electroencephalogram suggested atypical absence seizures, with migrating slow-wave activity observed during the interictal period. Whole exome sequencing of three family members indicated a novel mutation in the <i>AP2M1</i> gene, c.508C>T (p.R170W), in the patient. A total of six cases of autosomal dominant intellectual developmental disorder 60 with seizures associated with mutations in the <i>AP2M1</i> gene have been reported both domestically and internationally (including this study). The main clinical features included developmental delays (6 cases), language developmental disorders (5 cases), stereotyped movements (3 cases), a tendency to smile (1 case), and atypical absence seizures (4 cases). Interictal electroencephalograms showed widespread spike waves and spike-slow wave discharges (5 cases), and migrating slow-wave activity (1 case). The c.508C>T (p.R170W) mutation may be a hotspot for mutations in the <i>AP2M1</i> gene, and its clinical features are similar to those of Angelman syndrome.