CNKSR2 gene mutation leads to Houge type of X-linked syndromic mental retardation: A case report and review of literature. Issue 23 (11th June 2021)

• Record Type: Journal Article
• Authors: Kang, Qingyun; Yang, Liming; Liao, Hongmei; Wu, Liwen; Chen, Bo; Yang, Sai; Kuang, Xiaojun; Yang, Haiyang; Liao, Caishi
• Other Names: Saranathan. Maya section editor.
• Is Part Of: Medicine. Volume 100:Issue 23(2021)
• Publication Date: 2021-06-11
• Subjects: CNKSR2 -- intellectual disability -- seizure -- whole exome sequencing -- X-linked; Medicine -- Periodicals; Medicine -- Periodicals; Médecine -- Périodiques; Geneeskunde; Medicine; Periodicals; Periodicals; 610.5
• DOI: 10.1097/MD.0000000000026093
• Languages: English
• ISSNs: 0025-7974

Abstract

Abstract: Rationale: Mutations of connector enhancer of kinase suppressor of Ras-2 (CNKSR2) gene were identified as the cause of Houge type of X-linked syndromic mental retardation. The mutations of CNKSR2 gene are rare, we reporta patient carrying a novel nonsense mutation of CNKSR2, c.625C > T(p.Gln209 * ) and review the clinical features and mutations of CNKSR2 gene for this rare condition considering previous literature. Patient concerns: We report a case of a 7-year and 5-month-old Chinese patient with clinical symptoms of intellectual disability, language defect, epilepsy and hyperactivity. Genetic study revealed a novel nonsense variant of CNKSR2, which has not been reported yet. Diagnosis: According to clinical manifestations, genetic pattern and ACMG classification of mutation site as Class 1-cause disease, the patient was diagnosed as Houge type of X-linked syndromic mental retardation caused by CNKSR2 gene mutation. Interventions: The patient was administrated with a gradual titration of valproic acid (VPA). Outcomes: On administration of valproic acid, he had no further seizures. Lessons: This is the first time to report a nonsense variant in CNKSR2, c.625C > T(p.Gln209 * ), this finding could expand the spectrum of CNKSR2 mutations and might also support the further study of Houge type of X-linked syndromic mental retardation.