RESUMO
A 10 year-old female child developed erythema on the scalp,perioral area,neck,trunk,buttocks,palms and soles within 1 month after birth.Her skin was dry and rough,and the hairs were fine,soft,sparse and easily broken.As age advanced,typical hyperkeratosis and thickening of the skin occurred on an erythematous base.At the age of 5 years,the child developed photophobia and vision impairment.When the child was 8 years old,progressive hearing loss was observed.Physical examination revealed that the height and weight were 109 centimeters and 19 kilograms respectively.Skin examination showed fine,soft,sparse and easily-broken hair,large areas of brown plaques with crusts on the scalp,perioral area,neck,trunk and buttocks,and fissured,purulent and foul-smelling verrucous hyperplasia over these plaques.Brown to black hyperkeratotic plaques were scattered over the extremities,and diffuse hyperkeratosis occurred on the palms and soles.Both fingernails and toenails became thickened,cloudy and white with distal separation and deformation of the nail plate.As ophthalmic examination showed,the patient had photophobia,bilateral bulbar conjunctival hyperemia,corneal opacity and corneal vascular proliferation,and the visual acuity was 0.5 in the left eye and 0.2 in the right eye.Otolaryngological examination revealed moderate binaural sensorineural deafness.Stomatological examination showed enamel hypoplasia and diastema widening.Genetic testing showed a heterozygous mutation (c.C50T) in exon 2 of the gap junction protein beta 2 (GJB2) gene.Based on these clinical manifestations and examinations,the patient was diagnosed with keratitis,ichthyosis,and deafness (KID) syndrome.Skin lesions of the patient were significantly improved after the treatment with oral acitretin.
RESUMO
ObjectiveTo detect the mutation of GJB2 gene in a Chinese family with Vohwinkel syndrome.MethodsClinical data were collected from 5 patients with Vohwinkel syndrome in a family,and blood samples were obtained from the 5 patients and 4 unaffected individuals in the family as well as from 100 normal human controls.Genomic DNA was extracted and subjected to PCR for the amplification of the entire encoding and flanking sequences of GJB2 gene(1015 bp) followed by bidirectional sequencing with the ABI PRISM 3730 automatic DNA sequencer.Finally,sequence alignment was carried out by using the software Sequencher 4.10.1 Demo.ResultsA heterozygous missense mutation 196G→C in the GJB2 gene,which resulted in the substitution of aspartic acid by histidine at codon 66 (D66H) in the first extracellular domain of the protein,was observed in all the patients of this family,but in none of the 4 unaffected individuals in this family or the 100 normal human controls.ConclusionThe D66H missense mutation in the GJB2 gene may contribute to the occurrence of Vohwinkel syndrome in Chinese Han population.
RESUMO
Objective To investigate the molecular epidemiology of GJB2 mutations as a causative effect of prelingual deafness in northwestern China. Methods The medical history of 274 deaf-mute students was collected. Blood samples were obtained from them with informed consent. GJB2 gene sequences of genomic DNAs were amplified by polymerase chain reaction (PCR) with a pair of primers, and bidirectional sequencing of PCR products was performed and analyzed with DNAStar Software. Results A total number of 274 deaf-mute students were diagnosed as non-syndromic hearing impairment, and profound prelingual deafness. Two kinds of polymorphism, seven pathologic mutations and one novel mutation were revealed in the GJB2 screenings of them, and 79G→A and 341A→G were polymorphism with high frequency. Conclusion GJB2 gene mutation is the causative gene in the prelingual deafness with a high incidence of 10.95% in northwestern China. Based on the investigation, it is clear that screening of GJB2 gene mutation should play a significant role in early diagnosis of deaf-mutism in this region.