Phelan-McDermid syndrome in a Chinese pediatric patient: A case report - new heterozygous mutations lead to PMS.

This report describes a 3-year-old girl with Phelan-McDermid syndrome, a rare genetic condition that can look similar to autism. She had delays in language and social skills but improved significantly with rehabilitation therapy. The case shows how genetic testing can help distinguish between autism and similar genetic conditions.

This case report describes a 3-year-old Chinese girl diagnosed with Phelan-McDermid syndrome (PMS) caused by a new heterozygous deletion in chromosome 22q13.3. The patient presented with developmental delays, language difficulties, and social disorders but normal muscle tone. Brain imaging and EEG showed no abnormalities. Genetic testing revealed a 1.21 Mbp deletion in the 22:50014294-51220722 region, with both parents having normal genomes.

The case was initially considered for autism spectrum disorder diagnosis but was ultimately confirmed as mild PMS. Following systematic rehabilitation treatment, the child showed significant improvements in language, social, and motor abilities. This case highlights the potential for misdiagnosis between PMS and autism spectrum disorder.

Genetic testing should be considered for children presenting with autism-like symptoms to rule out PMS. Systematic rehabilitation can be beneficial for mild PMS cases. Clinicians should be aware of potential misdiagnosis between PMS and autism spectrum disorder.

Single case report limits generalizability. No control group or long-term follow-up data. Specific details about rehabilitation interventions not provided. No standardized outcome measures reported.

Phelan-McDermid syndrome, also known as chromosome 22q13.3 deletion syndrome, is a genetic disorder primarily caused by a chromosome 22q13.3 deletion or mutation. The primary clinical manifestations include intellectual disability, delayed language development, behavioral delays, hypotonia, autism spectrum disorder, mild deformities, and epilepsy. The clinical symptoms of this disease are associated with chromosomal deletions, and mild cases may be easily misdiagnosed as autism spectrum disorder. A 3-year-old girl was admitted for "chromosomal abnormality (heterozygous deletion) and developmental delay." After admission, we found that the child's overall growth retardation (mainly language and movement) and accompanied by obvious social disorders, but the muscle strength and muscle tension were basically normal; brain magnetic resonance imaging and electroencephalography were not obvious abnormalities.

Gene copy number variation analysis showed that there was a new pathogenic heterozygous deletion of 1.21 Mbp in the chromosome 22:50014294-51220722 region, and the genomes of both parents were wild-type. Combined with the clinical manifestations of the child, the child was finally diagnosed with mild Phelan-McDermid syndrome. The children received systematic rehabilitation treatment. Her language, social, and motor abilities were significantly improved.

Phelan-McDermid syndrome may be easily misdiagnosed as autism spectrum disorder. Our report enriches the clinical phenotype of Phelan-McDermid syndrome and provides a realistic and reliable basis for clinicians.