Congenital sensorineural hearing loss as the initial presentation of PTPN11-associated Noonan syndrome with multiple lentigines or Noonan syndrome: clinical features and underlying mechanisms

• Published in: Journal of medical genetics Vol. 58; no. 7; pp. 465 - 474
• Main Authors: Gao, Xue, Huang, Sha-Sha, Qiu, Shi-Wei, Su, Yu, Wang, Wei-Qian, Xu, Hui-Yan, Xu, Jin-Cao, Kang, Dong-Yang, Dai, Pu, Yuan, Yong-Yi
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group LTD 01.07.2021
• Subjects: Adolescent; Animals; Asians - genetics; Auditory system; beta Catenin - metabolism; Bioinformatics; Child; Child, Preschool; Cochlea; Cohort Studies; Congenital diseases; Ears & hearing; Embryos; Female; Gene Knockdown Techniques; Genes; Genomics; Genotypes; Hair cells; Hearing loss; Hearing Loss, Sensorineural - complications; Hearing Loss, Sensorineural - congenital; Hearing Loss, Sensorineural - epidemiology; Humans; Incidence; Infant; Inner ear; Male; Medical research; Mice; Mutants; Mutation; Noonan Syndrome - genetics; Noonan's syndrome; Otolaryngology; Otology; Patients; Phenotypes; Protein Tyrosine Phosphatase, Non-Receptor Type 11 - genetics; Protein Tyrosine Phosphatase, Non-Receptor Type 11 - metabolism; Research methodology; Signal Transduction; Spiral ganglion; Surgery; Wnt Proteins - metabolism; Zebrafish; Beijing China; China; diagnosis; clinical genetics
• ISSN: 0022-2593; 1468-6244
• DOI: 10.1136/jmedgenet-2020-106892

BackgroundGermline variants in PTPN11 are the primary cause of Noonan syndrome with multiple lentigines (NSML) and Noonan syndrome (NS), which share common skin and facial symptoms, cardiac anomalies and retardation of growth. Hearing loss is considered an infrequent feature in patients with NSML/NS. However, in our cohort, we identified a group of patients with PTPN11 pathogenic variants that were primarily manifested in congenital sensorineural hearing loss (SNHL). This study evaluated the incidence of PTPN11-related NSML or NS in patients with congenital SNHL and explored the expression of PTPN11 and the underlying mechanisms in the auditory system.MethodsA total of 1502 patients with congenital SNHL were enrolled. Detailed phenotype-genotype correlations were analysed in patients with PTPN11 variants. Immunolabelling of Ptpn11 was performed in P35 mice. Zebrafish with Ptpn11 knockdown/mutant overexpression were constructed to further explore mechanism underlying the phenotypes.ResultsTen NSML/NS probands were diagnosed via the identification of pathogenic variants of PTPN11, which accounted for ~0.67% of the congenital SNHL cases. In mice cochlea, Shp2, which is encoded by Ptpn11, is distributed in the spiral ganglion neurons, hair cells and supporting cells of the inner ear. In zebrafish, knockdown of ptpn11a and overexpression of mutant PTPN11 were associated with a significant decrease in hair cells and supporting cells. We concluded that congenital SNHL could be a major symptom in PTPN11-associated NSML or NS. Other features may be mild, especially in children.ConclusionScreening for PTPN11 in patients with congenital hearing loss and variant-based diagnoses are recommended.