[Screening of mitochondrial mutations of A1555G, A 3243G, and A7445G in MTRNR1, MTTL1 and MTTS1 genes in subjects with nonsyndromic sensorineural hearing loss]

Various frequencies of the mtDNA mutations have been reported from different population world wild. Three mitochondrial DNA [mtDNA] mutations including A1555G, A 3243G, and A7445G which occurred in MTRNR1, MTTL1 and MTTS1 genes were considered as the main causes of mitochondrial hearing loss in some populations. To determine the frequency of the A1555G, A3243G, and A7445G mutations in nonsyndromic sensorineural hearing loss subjects in Gilan. Forty six subjects with nonsyndromic sensorineural hearing loss were screened by provided questionnaire and audiogram from Gillan Welfare Organization. PCR-RFLP procedure was used in order to presence the MtDNA of A1555GA 3243G and A7445G mutations and was confirmed by subsequent direct sequencing. There was no MtDNA of A1555G, A3243G and A7445G mutation in the cohort study of 46 deaf individuals. Investigation of PCR-RFLP of the MTTL1 gene for existence A3243G mutation lead to identification a G3316A variant that destroyed other restriction site, in the other site of PCR fragment. Our finding indicated that possibility the association of mitochondrial mutations with deafness is very low in deaf subjects in north of Iran. According to existence the G3316A that its pathogenesis in relation to hearing loss phenotype has not stabilized, the frequency of G3316A is 1.46% that can be had highlights role of mitochondrial mutation in deafness

[Study of deafness associated with DFNB59 gene [Pejvakin] mutation in Fars province]

Hearing loss is the most frequent sensory disorder affecting 1 in 500 neonates with more than 50% of inherited cases. This trait is a very heterogeneous disorder and happens due to genetic or environmental causes or both. More than 46 genes may be involved in non-syndromic hearing loss. Recently, DFNB 59 gene has been shown to cause deafness in some Iranian populations. The aim of this study was to determine the role of DFNB 59 gene mutations causing deafness in a group of 130 deaf pupils in Fars province. This descriptive-laboratory based study investigated the frequency of DFNB59 gene mutations using PCR-SSCP/HA strategy. Two different DFNB59 polymorphism including 874G>A and 793C>G were found in 1 and 9 of 130 patients studied respectively. However, no DFNB59 mutation was identified. The results of this study shows that the association of DFNB59 mutations with deafness in Fars province is very low

[Detection of A1430G mutation in SCN1A gene in a patient affected by GEFS-like epilepsy in Chaharmahal va Bakhtiari province]

Background and aim: SCN1A gene encodes for neuronal voltage-gated sodium-channel ?-subunit. Mutations in this gene are the major cause of severe myoclonic epilepsy of infancy [Dravet syndrome] and generalized epilepsy with febrile seizures plus [GEFS[+]]. GEFS[+] is a heritable benign type of epilepsy associated with febrile seizures which belongs to Idiopathic Generalized Epilepsies with a marked clinical and genetic heterogeneity. The main objective of this research is screening of mutations in scn1a gene in patients affected by GEFS[+] and Idiopathic Generalized Epilepsy [IGE]

Methods: Genetic counseling was carried out with 30 patients and their family. Peripheral blood samples were collected from patients and DNA was extracted using salting out method. Standard PCR on 16[th]-26[th] exons of scn1a gene was optimized by employment of specific primers. PCR products were analyzed by SSCP in denaturant condition and sequenced in the next step

Results: Results showed a 4289c>g missense mutation in one patient affected by idiopathic generalized epilepsy. This mutation changes the alanine residue in 1430 position to glycine [A1430G]

Conclusion: More studies are needed to identify the direct role of this mutation in pathogenesis, however, heterozygotic genotype of this mutation is consistent with dominant feature of inheritance of Epilepsy