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Mutations in the GJB2 gene are the most frequently found mutations in patients with nonsyndromic hearing impairment. However, the mutation spectrum and prevalence of mutations vary among different ethnic groups. Every year, 30, 000 babies are born with congenital hearing impairment in China. In order to provide appropriate genetic testing and counseling to the family, we investigated the molecular etiology of nonsyndromic deafness in 135 unrelated school children attending Chifeng Municipal Special Education School in Inner Mongolia, China. The coding exon of the GJB2 gene was PCR amplified and sequenced. In addition, the 12S rRNA gene and tRNAser(UCN) of mitochondrial genome were screened for mutations responsible for hearing impairment. Sixty four GJB2 mutant alleles, including 60 confirmed pathogenic alleles and 4 unclassified variants, were identified in 31.1% (42/135) of the subjects. Twenty two subjects carried two pathogenic mutations and 20 subjects carried one mutant allele, including one subject with one autosomal dominant mutation. The 235delC was the most common mutation accounting for 65.6% (42/64) GJB2 mutant alleles. When compared to other Asian populations, our subject cohort had higher frequency of 235delC mutation than the Japanese population. The GJB2 mutant alleles account for 23.7% (64/270) of all chromosomes responsible for nonsyndromic hearing impairment. Testing of the 4 most prevalent deleterious frame shift mutations(235delC, 299_300delAT, 176_191del16, and 560_ 605ins46) in this cohort detected 90% of all GJB2 mutant alleles. These results demonstrate that effective genetic testing of the GJB2 gene for patients and families with nonsyndromic hearing impairment is possible in the Chinese population. Since the most common 309kb GJB6 deletion is not detected and only one 1555 A>G mutation in mitochondrial DNA is detected in our patients, investigation of mutations in other nuclear genes and/or environmental factors responsible for nonsyndromic hearing impairment in the Chinese population is necessary.

Mutations in GJB2 gene are the most frequently found mutations in patients with nonsyndromic hearing impairment. However, the spectrum and prevalence of mutations in this gene vary among different ethnic groups. In China, 30,000 infants are born with congenital hearing impairment annually. In order to provide appropriate genetic testing and counseling to the families, we investigated the molecular etiology of nonsyndromic deafness in 103 unrelated school children attending Nantong School for the Deaf and Mute in Jiangsu Province, China. The coding exon of the GJB2 gene was PCR amplified and sequenced. Sixty two GJB2 mutant alleles were identified in 35.9% (37/103) of the patients. Twenty five patients carried two pathogenic mutations and 12 patients carried one mutant allele. The 235delC was the most common mutation accounting for 69.4% (43/62) of GJB2 mutant alleles. The GJB2 mutant alleles accounted for 30.1% (62/206) of all chromosomes responsible for nonsyndromic hearing impairment. Testing of the 3 most prevalent deleterious frame shift mutations in this cohort detected 100% of all GJB2 mutant alleles. These results demonstrate that an effective genetic testing of GJB2 gene for patients and families with nonsyndromic hearing impairment is possible.

License plate recognition is one of the core technologies in intelligent traffic control. There are broad application prospects in intelligent car park management, highway automatic toll collection and violation detection. This technology combines computer technology, image processing, pattern recognition and many other disciplines, which is an important research topic in the transport sector in recent years. In this paper, the license plate location method is based on mathematical morphology method and a modified RBF neural network algorithm to complete the identification. There is a good recognition result through MATLAB simulation experiments.