Medical Genetic Department, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China.
Department of Clinical Laboratory, Medical College of Qingdao University, Qingdao, Shandong 266071, P.R. China.
Mol Med Rep. 2020 Jan;21(1):387-392. doi: 10.3892/mmr.2019.10818. Epub 2019 Nov 12.
Smith‑Fineman‑Myers syndrome (SFMS) is a rare inherited disorder characterized mainly by mental retardation and anomalies in the appearance of patients. SFMS is caused by a mutation in the α‑thalassemia/mental retardation syndrome X‑linked (ATRX) gene and has an X‑linked recessive pattern. In the present study, a novel ATRX mutation was identified, and the association between its genotype and the phenotype was explored in a Chinese Han family with SFMS. This study aimed to lay a foundation for prenatal diagnosis for this family. Briefly, genomic DNA was extracted from peripheral blood samples obtained from the family. High‑throughput genetic sequencing was employed to detect the whole exome; subsequently, Sanger sequencing was performed to verify the candidate mutations. Clinical analysis of the proband was also accomplished. Consequently, a novel missense ATRX mutation was identified comprising a single nucleotide change of C to T, which caused an amino acid substitution at codon 172 in exon 7 (c.515C>T; p.Thr172Ile) of the proband. This mutation was found to co‑segregate in the present SFMS pedigree and was located in a highly conserved region of the ATRX protein, thus suggesting that it may be a pathogenic mutation. Taken together, these findings provided novel information that may lead towards an improved understanding of the genetic and clinical features of patients with SFMS, thereby facilitating a more accurate prenatal diagnosis of SFMS.
Smith-Fineman-Myers 综合征 (SFMS) 是一种罕见的遗传性疾病,主要表现为智力障碍和患者外貌异常。SFMS 是由α-地中海贫血/智力迟钝综合征 X 连锁 (ATRX) 基因突变引起的,呈 X 连锁隐性遗传模式。本研究鉴定了一种新型 ATRX 突变,并探讨了其基因型与表型的关系在中国汉族 SFMS 家系中。本研究旨在为该家系的产前诊断奠定基础。简而言之,从该家系的外周血样本中提取基因组 DNA。采用高通量基因测序检测全外显子;随后,进行 Sanger 测序验证候选突变。对先证者进行临床分析。结果发现了一种新型错义 ATRX 突变,由单个核苷酸 C 到 T 的变化引起,导致 7 号外显子(c.515C>T;p.Thr172Ile)中第 172 位密码子的氨基酸替换。该突变在本 SFMS 家系中共同分离,并位于 ATRX 蛋白高度保守区域,提示可能是致病突变。综上所述,这些发现提供了新的信息,可能有助于更好地理解 SFMS 患者的遗传和临床特征,从而更准确地进行 SFMS 的产前诊断。