| Objective:Congenital enlarged vestibular aqueduct (EVA) was a nonsyndromic disease with enlarged vestibular aqueduct and sensorineural hearing loss. We analyzed its phenotypes, genotypes and relationship between them by studying EVA patients in clinical characteristics, audiomerty, iconography and gene mutation of GJB2, SLC26A4 and mtDNA gene.Methods: We collected 60 EVA patients who were treated by cochlear implantation for our study. All patients were tested by PTA(or behavior audiomerty if the patients couldn’t perform well), ABR,40HzAERP, ASSR, DPOAE, temporal bone high-resolution CT and inner ear MRI. SNPscan technology which detected the common GJB2, SLC26A4 and mtDNA gene mutations was carried out after the patients signed informed consent.Results:1. The typical performance of EVA patients was progressive or fluctuate SNHL with hearing loss from mild to extremely severe in childhood. Most patients had complications of tinnitus and vertigo. ANSR accounted for 43.30% which was the characteristic of EVA patients. We found 3 malformations which included EVA, EVA with Mondini and Mondini by using temporal bone high-resolution CT and inner ear MRI tests. They accounted for 48.20%,40.10% and 11.70%.2. In 53 EVA patients,47 patients carried SLC26A4 gene mutation, the mutation frequency was 88.68%. We found 25 genotypes, the most common genotype was c.919-2A>G/c.919-2A>G, accounting for 28.30%. The second most common genotype was c.919-2A>G/c.1229C>T, accounting for 5.66%. We found 18 mutation types, c.919-2A> G is the most common mutation type with allele frequency of 47.16%, the second most common mutation type was c.2168A>G with allele frequency of 8.74%. Other 5 common mutation types were c.1174A>T, c.754T>C, c.1229C>T, c.1517T>G and c.1707+5G>A. 84.91% of the patients carried at least one of these mutation types, while 62.27% of the EVA patients carried two of these mutation types.3. We found 27 patients with EVA, 26 cases were EVA with Mondini malformation and 7 cases were Mondini malformation. Cases of Mondini malformation was significantly different from EVA or EVA with Mondini malformation on mutation frequency (P< 0.01).4. GJB2 and SLC26A4 gene mutation frequencies were significantly different(χ2= 65.185, P <0.001). There was significant difference between them on frequency of diallele mutation (χ2= 112.710, P< 0.001).Conclusions:1. EVA patients with severe sensorineural hearing loss were always dagnoised in childhood and had complications of tinnitus and vertigo. PTA almost showed descending high-frequency. ANSR was the characteristic of EVA patients. The golden standard for clinical diagnosis was iconography. Cochlear implantation was feasible for these patients with bilateral hearing loss.2. SLC26A4 gene was closely related to EVA, the most common mutation type was c.919-2A> G, the most common genotype was c.919-2A>G/c.919-2A>G. Other common mutation types were c.2168A>G, c.1174A>T, c.754T>C, c.1229C>T, c.1517T>G and c.1707+5G>A, which covered most EVA patients together with c.919-2A>G. It was valuable for diagnosing EVA by gene chip in Gansu province.3. Mondini malformation was significantly different from EVA or EVA with Mondini malformation on mutation frequency, new classification criteria of inner ear malformation should be canonized which divided Mondini malformation into IP-Ⅰ and IP-Ⅱ. This was useful for clinical diagnosis and further study.4. There was little relationship between GJB2, mtDNA genes and EVA, They were not responsible for EVA.Objective: To investigate the prevalence of hearing loss in the neonatal intensive care unit (NICU) by hearing screening. We compared the prevalence between NICU newborns and general newborns in Gansu province. We also analyzed the relationship between high risk facts and hearing loss. Then we investigated the prevalence of gene mutations which included GJB2, SLC26A4 and mtDNA in NICU and compared the prevalence between NICU newborns and general newborns in Gansu province. We also explored the implementation of hearing combined with deafness gene screening for NICU in Gansu province.Methods:We collected 1032 patients from NICU and general newborns from our past study. All patients were tested by ABR and DPOAE. SNPscan technology which detected the common GJB2, SLC26A4 and mtDNA gene mutations was carried out after the patients signed informed consent.Results:1. In the NICU hearing screening,191(18.51%) newborns didn’t pass the fist-step screening and 127(12.31%) newborns didn’t pass the second screening. In the general hearing screening 15.40% of newborns didn’t pass the fist-step screening and 9.36% of newborns didn’t pass the second screening. The refer frequency of hearing screening between NICU newborns and general newborns had statistic difference (P<0.01)2. In the NICU gene screening,14.00% of newborns carried monoallelic mutation and 2.00% of newborns carried diallele mutation. In the general gene screening,2.37% of newborns carried gene mutation and 0.02% of newborns carried diallele mutation. The frequency of monoallelic mutation and diallele mutation frequency between NICU newborns and general newborns had statistic difference (P<0.01).3. We found 2 newborns carried homozygous mutation of mtDNAA1555G, they all pasted the hearing screening.Conclusions:1. NICU newborns had higher refer frequency of hearing screen than general newborns.2. NICU newborns had higher risk of gene mutation than general newborns.3.Hearing combined gene screening was suitable for NICU newborns in Gansu province, this screening strategy could find potential cases of hearing loss in early time, it may be prevalent for deafness screening for NICU in Gansu province. |
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