De novo mutation of the TSC2 gene in patient with Tuberous Sclerosis Complex-Associated Neuropsychiatric Disorders (TAND) Phenotype: a case report.

Tuberous sclerosis complex (TSC) is a neurocutaneous disease caused by a mutation in the TSC1 or TSC2 gene. There are several neuropsychiatric manifestations associated with TSC known as TSC-associated neuropsychiatric disorder (TAND). This article concerns neuropsychiatric manifestations in children with the TSC2 gene mutation, with genetic analysis findings using whole-exome sequencing. Case: A 17-year-old girl presented with TSC, absence and focal epilepsy, borderline intellectual functioning, organic psychosis, and renal angiomyolipoma. She was emotionally unstable and preoccupied with irrelevant fears. In the physical examination, we found multiple hypomelanotic maculae, angiofibroma, and a shagreen patch. The intellectual assessment result with the Wechsler Adult Intelligence Scale at 17 was borderline intellectual functioning. Brain MRI showed cortical and subcortical tubers in the parietal and occipital lobes. Whole-exome sequencing was conducted, and the result was a missense mutation in exon 39 of the TSC2 gene [NM_000548.5:c.5024C>T (NP_000539.2:p.Pro1675Leu)]. The Sanger sequencing of the patient's parents revealed no mutations in the TSC2 gene, confirming the patient's de novo mutation. The patient was given several antiepileptic and antipsychotic drugs. Clinical discussion: Neuropsychiatric manifestation is a common phenotype in the TSC variant, and psychosis is one of the rare TAND symptoms in children. Conclusions: The neuropsychiatric phenotype and genotype in TSC patients are rarely reported and evaluated. We reported a female child with epilepsy, borderline intellectual functioning, and organic psychosis associated with a de novo mutation of the TSC2 gene. Organic psychosis is a rare symptom of TAND which also manifested in our patient.

Phenotypes of a female patient with novel de novo frameshift ARX variant identified by whole-exome sequencing: a case report.

Variants in the aristaless-related homeobox (ARX) gene cause a diverse spectrum of phenotypes of neurodevelopmental disorders (NDD) in male patients. This article describes the role of genetic testing using whole-exome sequencing (WES) in detecting a novel de novo frameshift variant in the ARX gene in a female patient with autism, seizure, and global developmental delay. Case presentation: A 2-year-old girl with frequent seizures, global developmental delay, and autistic features was referred to our hospital. She was the second child of consanguineous non-affected parents. She had a high forehead, mildly prominent ears, and prominent nasal root. A generalized epileptiform discharge was noted in her electroencephalography. Brain MRI revealed corpus callosum agenesis, cerebral atrophy, and a left parafalcine cyst. The WES result showed a likely pathogenic variant identified as a novel de novo deletion in exon 4 of the ARX gene, which creates a frameshift variant. The patient is on dual therapy of antiepilepsy drugs, physiotherapy, speech therapy, occupational therapy, and oral motor exercises. Clinical discussion: Variants in the ARX gene can result in various phenotypes in males transmitted from asymptomatic carrier females. However, several reports showed that the ARX variants might cause phenotypes in females with milder symptoms than affected males. Conclusion: We report a novel de novo ARX variant in an affected female with a NDD. Our study confirms that the ARX variant might cause remarkable pleiotropy phenotypes in females. Moreover, WES could help to identify the pathogenic variant in NDD patients with diverse phenotypes.