[The clinical phenotype and gene analysis of syndromic deafness with PTPN11 gene mutation].

Objective: To analyze the clinical phenotype and screen the genetic mutations of hereditary deafness in three deaf families to clarify their molecular biology etiology. Methods: From January 2019 to January 2020, three deaf children and family members were collected for medical history, physical examination, audiology evaluation, electrocardiogram and cardiac color Doppler ultrasound, temporal bone CT examination, and peripheral blood DNA was obtained for high-throughput sequencing of deafness genes. Sanger sequencing was performed to verify the variant sites among family members. The pathogenicity of the variants was evaluated according to the American College of Medical Genetics and Genomics. Results: The probands in the three families had deafness phenotypes. In family 1, proband had multiple lentigines, special facial features, growth retardation, pectus carinatum, abnormal skin elasticity, cryptorchidism and other manifestations. In family 2, proband had special facial features, growth retardation and abnormal heart, and the proband in family 3 had growth retardation and abnormal electrocardiogram. Genetic testing of three families detected three heterozygous mutations in the PTPN11 gene: c.1391G>C (p.Gly464Ala), c.1510A>G (p.Met504Val), c.1502G>A (p.Arg501Lys). All three sites were missense mutations, and the mutation sites were highly conserved among multiple homologous species. Based on clinical manifestations and genetic test results, proband 1 was diagnosed with multiple lentigines Noonan syndrome, and probands 2 and 3 were diagnosed with Noonan syndrome. Conclusion: Missense mutations in the PTPN11 gene may be the cause of the disease in the three deaf families. This study enriches the clinical phenotype and mutation spectrum of the PTPN11 gene in the Chinese population.目的： 通过对3个PTPN11基因突变的综合征型耳聋家系的临床表型和基因进行分析，了解其分子生物学病因。 方法： 对2019年1月至2020年1月在昆明市儿童医院就诊的3个耳聋家系进行病史采集，体格检查，听力学评估，心电图、心脏彩色多普勒血流成像及颞骨CT检查，之后取先证者外周血DNA进行耳聋基因高通量测序，并针对变异位点对家系成员进行Sanger测序验证，根据美国医学遗传学与基因组学学会制定的变异解读标准对变异的致病性进行评估。 结果： 3个家系中先证者均有耳聋表型。家系1先证者合并多痣，特殊面容，生长迟缓，鸡胸，皮肤弹性异常，隐睾等表现；家系2先证者合并特殊面容，生长迟缓及心脏异常；家系3先证者合并生长迟缓和心电图异常。对3个家系进行基因检测，发现PTPN11基因3个杂合突变：c.1391G>C（p.Gly464Ala）、c.1510A>G（p.Met504Val）和c.1502G>A（p.Arg501Lys）。3个位点均为错义突变，且突变位点在多个同源物种间高度保守。综合临床表现及基因检测结果，先证者1诊断为多痣Noonan综合征，先证者2、3诊断为Noonan综合征。 结论：PTPN11基因的错义突变可能是3个耳聋家系的致病原因，该研究丰富了中国人群PTPN11基因临床表型和突变谱。.