• Qingyun Kang, Liming Yang, Hongmei Liao, Liwen Wu, Bo Chen, Sai Yang, Xiaojun Kuang, Haiyang Yang, and Caishi Liao.
• Department of Neurology, Hunan Children's Hospital, Ziyuan Road, Changsha, Hunan, P.R.China.
• Medicine (Baltimore). 2021 Jun 11; 100 (23): e26093e26093.

RationaleMutations 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 ConcernsWe 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.DiagnosisAccording 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.InterventionsThe patient was administrated with a gradual titration of valproic acid (VPA).OutcomesOn administration of valproic acid, he had no further seizures.LessonsThis 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.Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.

33 keywords...

hide…