An Analysis To COL1A1 Gene Mutation About A Chinese Family With Otosclerosis

Otosclerosis is a kind of disease that cause by primary focal lesions of bone lost. The bone density lost due to focal lamellar bone absorption and is replaced by the sponge-like new bone which is rich in blood vessels and cells. Then the vascular reduced, meanwhile the substance of bone sedimentated which lead to the bone sclerosis lesions.Otosclerosis has the highest incidence of 0.2%- 1% in the Caucasian, but the incidence to the yellow race and the blacks is very low. The disease happens to a certain family, most scholars believe that otosclerosis is autosomal dominant inheritance but someone think that is autosomal recessive inheritance. Generally, The sufferers of otosclerosis have the clinic symptoms like deafness or tinnitus between 20-40 years old. Some of them who are severe have to face the significantly reduced in quality of life and work ability. The article study and summarize the clinical examination and genic mutation about a Chinese family with Otosclerosis .Objective: Try to find out a known or unknown gene COL1A1 mutation to explore the possible pathogenesis of Otosclerosis in our country, by doing the clinical and genetic analysis to the family with otosclerosis , and the sequencing studies for typeâ… collagen gene (COL1A1 gene) .Methods: Collect clinical data and blood samples of a Chinese family with Otosclerosis that we have found, then drew the genealogy chart. We also summarize and analyze the clinical features and then extract the genomic DNA in peripheral blood specimens. Besides, Primers were designed to do amplification and sequencing analysis for the patients'and normals'COL1A1 exon in the famaily, then compare the results of sequencing the corresponding gene with the GeneBank sequence comparison of normal to search the mutation. Different groups of gene mutation rate of the data were used of chi-square test SPSS15.0.Results:1. Clinical features:The 4-generation pedigree, a total of 25 members, of which three cases of dead, others were living in Fujian. The proband is the Second-generation of adult male patients. 21 persons of the families of receive investigation and physical examination, 4 of them has been diagnosed with clinical otosclerosis. They areâ…¡-2,â…¡-3,â…¢-3 andâ…¢-9. The scene examination showed that there were 6 cases including 11 ears of conductive hearing loss , 10 cases including 18 ears of high-frequency (> 4000hz) hearing loss , 8 cases including 9 ears of tinnitus, and 3 cases of vertigo. We did not find out blue sclera patients with Pure tone audiometry, and patients with any other signs of comprehensive deaf. The genealogy chart of the amily shows autosomal dominant inheritance.2. Gene mutation:â… . In the 44 exon 130Bp , there T / C heterozygosity were found, but the point mutation in the intron.â…¡. The 46 and 50 exon were not found mutations.â…¢. 3'UTR area 230Bp of the families were found the missing of GCCC.Conclusion:1. The Genetic approach of this Chinese family with Otosclerosis is autosomal dominant inheritance2. GCCC with the 3'UTR in the COLIAI of the family were found missing, the mutation has never been reported at home and abroad.