A nonsense mutation in the CUL3 gene in a Chinese patient with autism spectrum disorder and epilepsy: A case report.

RATIONALE: CUL3 (OMIM: 603136) encodes cullin-3, a core component of ubiquitin E3 ligase. Existing medical research suggests that CUL3 mutations are closely related to neurodevelopmental disorder with or without autism or seizures (neurodevelopmental disorder with autism and seizures, OMIM: 619239). However, the number of published case reports of autism spectrum disorder due to CUL3 gene mutations is limited.

PATIENT CONCERN: A four-year-old Chinese girl presented with generalized epilepsy, and then exhibited developmental regression, including loss of her speaking ability, eye contact aversion, and stereotyped behavior.

DIAGNOSES: Whole-exome sequencing identified a nonsense mutation in the CUL3 gene, being c.2065A > T (p.Lys689*); no previous similar case was reported. The final diagnosis was autism, epilepsy, and motor growth retardation.

INTERVENTION: In order to improve quality of life of the patient, she was provided with exercise rehabilitation training and autism behavioral guidance therapy for 3 months.

OUTCOMES: The patient's exercise capacity had improved, and improvements in autism symptoms were not obvious.

LESSONS: For clinicians, patients with developmental regression accompanied with concurrent epilepsy and autism spectrum disorder should be advised that relevant genetic tests are necessary to clarify the diagnosis.