Frequency of mutations in the GJB2 and 125 rRNA genes in Egyptian patients with hereditary hearing loss

The aim of this study was to determine the prevalence of GJB2 and 12S rRNA mutations in Egyptian families with hereditary hearing loss. Twenty three families showing hereditary hearing loss analyzed. Seventeen of these families showed non-syndromic sensorineural hearing loss while the rest 4 families were showing syndromic form of hearing loss. All subjected were examined by clinical evaluation and genetic analysis of their samples, including PCR, restriction assays, sequencing and SSCP. The 35 delG was found in 23.53% [4/17] of the families or in 24 of 242 [16.9%] investigated alleles. Four patients were heterozygous carriers and 10 patients were homozygous for the 35 delG mutations. No other mutations of GJB2 have been reported. No A155G mutation have been detected in the study group. These results emphasize the importance of genetic diagnosis and genetic counseling of deaf patients in Egypt

Incidence of ototoxicity in patients receiving cytotoxic medication

This study was done with the objective to evaluate the efficacy of otoacoustic emission in early detection of cochlear lesion due to ototoxic drugs. A total of thirty five patient twenty of them were receiving cisplatin and fifteen were receiving vincristine. They were receiving the therapy at the Oncology unit, Assiut university hospital. All study patients were submitted to complete audiological evaluation including pure tone audiometry, speech audiometry, Immittancemetry test and otoacoustic emissions [OAE] including, Transient evoked otoacoustic emissions. This evaluation was done before drug therapy and after each subsequent course of therapy. Comparisons were made between basic pre-therapy evaluation and the serial follow up for three mouths [by audiometry and otoacoustic emission test]. After therapy, significant evaluation of pure tone thresholds were demonstrated in high frequencies [4-8 KHZ] in 67% of patients receiving cisplatin and 13.3% in patients receiving vincristine therapy. There were a significant decrease in OAE amplitude specially at high frequency band; 3-4 KHZ in both groups even in patients with no changes in their audiometric thresholds. In conclusion vincristine and cisplatin therapy could produce Ototoxicity due to cochlear lesion and TEOAEs were more a sensitive than audiometric test in early detection of cochlear Ototoxicity and could be used for its monitoring