Genetic and clinical phenotypic analysis of familial stapes sclerosis caused by an NOG mutation

BACKGROUND: The noggin protein encoded by the NOG gene can interfere with the binding of bone morphogenetic protein to its receptor, thus affecting bone and joint development. The symptoms include abnormal skeletal development and conductive deafness. METHODS: In a retrospective study, clinical data of the proband and her family members, including 8 people and 50 healthy normal controls, were collected. Second-generation sequencing was performed on peripheral blood samples from them. RESULTS: The sequencing analysis indicated that in the proband, the NOG gene had a c.532T > C, p.C178R (cytosine deletion, NM_005450.6:c.532T > C), leading to an amino acid change. The proband's father, grandmother, second sister, and third sister also had this mutation, whereas family members with normal phenotypes did not have the mutation. CONCLUSION: Analysis of this family showed that the novel presentation of the c.532T > C, p.C178R mutation in the NOG gene resulted in syndrome-type autosomal dominant inheritance reflected in a mild clinical phenotype, which is of great importance for further studies of the clinical phenotype and pathogenesis of stapes sclerosis.