association study on IL16 gene polymorphisms with the risk of sporadic alzheimer's disease

Interleukin-16 [IL-16] is an important regulator of T cell activation and was reported to act as a chemoattractant agent. There are evidences that IL16 can control the neuroinflammatory processes in Alzheimer's Disease [AD]. This study was performed to investigate the role or association of IL16 polymorphisms, rs11556218 and rs4778889 with the risk of late-onset Alzheimer's disease [LOAD] in Iranian population. Totally, 148 AD patients and 137 nondemented and age-matched subjects were recruited in this study. Genotyping of rs11556218 T/G and rs4778889 T/C polymorphisms was performed by PCR-RFLP method using the NdeI and AhdI restriction enzymes, respectively. Statistical analysis of rs11556218 genotypes showed a protective effect against AD in the heterozygote genotype [p=0.001, OR=0.16] as well as rs4778889 [p=0.001, OR=0.23]. Frequency of rs11556218 allele T was higher in controls than patients [p= 0.001, OR=0.32]. However, there was no significant difference in the frequencies of rs4778889 alleles between the AD patients and controls. Our results indicate that the rs11556218 and rs4778889 polymorphisms have a protective role in the development of sporadic AD in Iranian population

Investigating Seven Recently Identified Genes in 100 Iranian Families with Autosomal Recessive Non-syndromic Hearing Loss

Objectives: Hearing loss [HL] is the most common sensory disorder, and affects 1 in 1000 newborns. About 50% of HL is due to genetics and 70% of them are non-syndromic with a recessive pattern of inheritance. Up to now, more than 50 genes have been detected which are responsible for autosomal recessive non-syndromic hearing loss, [ARNSHL]. In Iran, HL is one of the most common disabilities due to consanguineous marriages. The aim was to investigate the prevalence of three new ARHL genes [GJB4, GJC3, and SLITRK6] reported in neighboring countries among Iranian families with ARNSHL.

Methods: One hundred unrelated families with at least two affected siblings in consanguineous marriage, who were negative for GJB2 gene mutations, were selected. By using three STR markers for each gene, homozygosity mapping was performed.

Results: Two families showed linkage to GJB4, six families were linked to GJC3 and only one family linked to SLITRK6. The samples of these families who showed linkage were sent for Sanger sequencing to detect the causative mutations. However, after analyzing the sequencing results, no mutation could be detected in either of the families. Molecular analysis for these nine families is underway in order to determine the pathogenic mutations using whole exome sequencing.

Discussion: These data demonstrate a very low prevalence of mutation in these three genes [GJB4, GJC3, and SLITRK6] in the Iranian population, since no mutation was detected in our study group of 100 families.