Open AccessCNKSR2 gene mutation leads to Houge type of X-linked syndromic mental retardation
Author(s) -
Qingyun Kang,
Liming Yang,
Hongmei Liao,
Liwen Wu,
Bo Chen,
Shan Yang,
Xiaojun Kuang,
Haiyang Yang,
Caishi Liao
Publication year - 2021
Publication title -
medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.59
H-Index - 148
eISSN - 1536-5964
pISSN - 0025-7974
DOI - 10.1097/md.0000000000026093
Subject(s) - nonsense mutation , medicine , genetics , nonsense , mutation , valproic acid , gene , intellectual disability , epilepsy , gene mutation , pediatrics , psychiatry , missense mutation , biology
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.