title: Otosclerosis Associated with a De Novo Mutation -832G > A in the TGFB1 Gene Promoter Causing a Decreased Expression Level.
abstract: Otosclerosis (OTSC) is defined by abnormal bone remodeling in the otic capsule of middle ear which leads to conductive hearing loss. In our previous study, we have identified a de novo heterozygous mutation -832G > A in the promoter of TGFB1 in an otosclerosis patient. In the present study, we progressively screened this mutation in a cohort of 254 cases and 262 controls. The family members of the patient positive for -832G > A variation were also screened and found inheritance of this variation only to her daughter. Interestingly, this variation is associated with a decreased level of the TGFB1 transcript in the patient compared to her parents and controls. In silico analysis of this mutation predicted the altered binding of two transcription factors v-Myb and MZF1 in the mutated promoter sequence. Further, functional analysis of this mutation using in vitro luciferase and electrophoretic mobility shift assays revealed that this variation is associated with decreased gene expression. In conclusion, this study established the fact that TGFB1 mutation -832G > A altered the TGFB1 promoter activity, which could affect the susceptibility to otosclerosis development. Further, systemic analysis of TGFB1 gene sequence and expression analysis of this gene might reveal its precise role in the pathogenesis of otosclerosis.
authors.affiliation: Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, India.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Priyadarshi
authors.affiliation: Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, India.
authors.forename: Kirtal
authors.initials: K
authors.lastname: Hansdah
authors.affiliation: Department of Ear, Nose, and Throat (ENT), Shrirama Chandra Bhanj (SCB) Medical College, Cuttack, India.
authors.forename: Chinmay Sundar
authors.initials: CS
authors.lastname: Ray
authors.affiliation: Department of Ear, Nose, and Throat (ENT), Shrirama Chandra Bhanj (SCB) Medical College, Cuttack, India.
authors.forename: Narayan Chandra
authors.initials: NC
authors.lastname: Biswal
authors.affiliation: Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar, India.
authors.forename: Puppala Venkat
authors.initials: PV
authors.lastname: Ramchander
mesh_terms: D000328:Adult; D005260:Female; D015870:Gene Expression; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D040941:Heredity; D006801:Humans; D008297:Male; D008875:Middle Aged; D010040:Otosclerosis / Q000235:genetics* / Q000473:pathology*; D017354:Point Mutation; D011401:Promoter Regions, Genetic; D053773:Transforming Growth Factor beta1 / Q000096:biosynthesis* / Q000235:genetics*; D055815:Young Adult
chemical_list: C508960:TGFB1 protein, human; D053773:Transforming Growth Factor beta1