Investigation of genetic causes of intellectual disability in Kerman province, south east of Iran

Intellectual disability [ID] has a worldwide prevalence of 1-3% and results from extraordinary heterogeneous. To shed more light on the causes of ID in Kerman Province, in Southeast Iran, we set out in 2008 to perform systematic clinical studies and homozygosity mapping in large Iranian families with ID. Fifty seven families with a minimum of two mentally retarded children from Kerman Province were initially tested for metabolic disorders, by Tandem mass spectrometry. Fragile X testing and standard karyotyping were performed for all probands of families. Cases with autosomal recessive [AR] pattern of inheritance and microcephaly were subjected to homozygosity mapping by using several microsatellite markers for known MCPH loci. Three out of seven families with X-linked pattern of inheritance were positive for fragile X syndrome. Chromosome abnormality was not observed in any of dysmorphic patients and all families were negative for metabolic tests. Among the remaining 50 families of AR ID, six were found to be microcephalic, of which 2 linked to two MCPH loci [33.3%]. The rest 4 families were not linked to any of the known loci. The results of this study showed that ID with microcephaly comprised 12% of ID cases in Kerman Province. In two families with apparent linkage to the MCPH5 and MCPH6 locus, mutation screening was not successful, which might indicate that either the mutation is located in the regulatory sequences of the gene or that there might be another genes present in these regions, which is mutated in such cases

Clinical and molecular aspects of Sjogren-Larsson syndrome reported in an iranian consanguineous family with triplet affected individuals

Sjogren Larsson Syndrome [SLS; OMIM: 270200] is an autosomal recessive neurocutaneous disorder characterized by mental retardation, congenital ichthyosis and spastic paraplegia. SLS is caused by mutations in aldehyde dehydrogenase 3A2 isoform 2 [ALDH3A2], which encodes fatty aldehyde dehydrogenase [FALDH]. This enzyme metabolizes the NAD-dependent oxidation of long chain aldehyde derived from lipid metabolism. Up to now, more than 72 mutations have been reported in SLS patients. DNA was extracted from peripheral blood of all the five patients, one healthy sibling and their parents using standard procedures. SNP genotyping was performed using the GeneChip [registered sign]. Multipoint linkage analyses and non-parametric linkage analysis was performed too. Results: Here, we report an interesting family with five affected individuals with a novel splice site mutation [c.1107+1delGTA] in ALDH3A2. In absence of capability to measure FALDH activity in Iran, DNA sequencing of the ALDH3A2 gene could lead to the identification of causative mutation and confirm the diagnosis

[Screening of DFNB4 locus in Iranian families with hereditary hearing impairment]

Mutations in the SLC26A4 gene in the DFNB4 locus is responsible for syndromic [Pendred syndrome] and non-syndromic hereditary hearing loss [HHL]. In many populations, mutations in this gene have been reported as a second cause of HHL. The objective of this study was to investigate the prevalence of SLC26A4 mutations in our HHL consanguineous families. After completing clinical evaluation and obtaining signed consent forms from each family, we included 80 families with two or more affected individuals, referred to the Genetics Research Center [GRC]. All families that previously tested negative for the DFNB1 locus were candidates for homozygosity mapping using STRs for DFNB4 locus. Families localized to this region were subjected to complete DMA sequencing. Twelve out of 80 families were mapped to DFNB4. Sequence analysis of 12 linked families revealed 10 mutations in 8 families. [T420I, 1197delT, G334V, R409H, T721M, R79X, S448L, L597S, 965insA, and L445W]. The T420I, G334V, L597S and R79X were novel mutations; we did not find any mutation in the four linked families, nor did we detect any nonsyndromic families with mutation in the SLC26A4 gene. We have been able to identify mutation in the SLC26A4 gene in only 8 of 80 families. In 12 families, we detected some degree of diffuse or nodular goiter; three out of 12 families showed thyroid function impairment and in five of 12 families there were positive prechlorate discharge tests. Eight families that showed mutation had normal temporal bone scan. This investigation, demonstrated that the SLC26A4 gene mutation is the most prevalent syndromic hereditary hearing loss in Iran, a finding in accordance with reports from other countries

Evaluating the effect of DMSO concentrations on y-globin expression in Hull cells

Evaluating the effect of DMSO concentrations on g-globin expression in Hu11 cells Asgharian AM1, Banan M2, Deilami Z1, Gharesouran J3, Ghasemi S4, Behjati F2, Javadi GR5, Kahrizi K6, Najmabadi H7 1 PhD Student of cell and molecular biology, Department of Biology, Islamic Azad University, Science and Research Branch, Tehran, Iran. 2 Assistant professor, Genetics Research Center, University of Social Welfare and Rehabilitation Sciences. Tehran, Iran. 3 Student of MSc of Genetics, Genetics Research Center, University of Social Welfare and Rehabilitation Sciences. Tehran, Iran. 4 MSc of Genetics,Genetics Research Center, University of Social Welfare and Rehabilitation Sciences. Tehran, Iran. 5 Associate Professor, Department of Biology, Islamic Azad University, Science and Research Campus, Tehran, Iran. 6 Associate Professor, Genetics Research Center, University of Social Welfare and Rehabilitation Sciences. Tehran, Iran. 7 Professor, Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran Abstract Background: Understanding of the mechanisms involved in gamma- to beta-globin switching may be important for development of treatment options for b-thalassemia. Such studies require the availability of relevant cellular model systems. One such cell type is Hu11, a mouse erythroleukemia [MEL] cell line containing the human b-locus. MEL and Hu11 cells differentiate in the presence of the chemical dimethyl sulfoxide [DMSO]. Nevertheless, levels of gamma-globin induction in Hu11 cells after DMSO treatment have not been determined. In the present study, we determined gamma-globin levels in Hu11 cells after treatment with various DMSO concentrations. Materials and methods: Hu11 cells were cultivated in various DMSO concentrations and the levels of gamma-globin were determined by real-time PCR. Results: Our study showed that hemoglobin in Hu11 cells treated with 1% and 2% DMSO was increased by approximately 5 and 10 folds. Moreover real-time PCR results showed that g-globin levels using the indicated DMSO levels were increased by 66 and 298 folds, respectively. Hu11 cells differentiate in the presence of DMSO, and in doing so, their gamma-globin levels are increased. Therefore these cells can be used to study the mechanisms of gamma-globin induction. Such studies may be beneficial for the treatment of beta-thalassemia

[Surveying SMN gene deletions in Iranian patients with spinal muscular atrophy and prenatal diagnosis]

Spinal muscular atrophy is a group of alpha-motor neuron. There are three genes for this disorder, of which SMN with two copies centromeric and telomeric is the most important one. In 95% of SMA patient's telomeric copy of SMN is homozygously deleted and the remaining has point mutation in this gene. In most of the patient's, exon 7 and 8 of SMN 1 is deleted. Therefore, analysis of SMN1 mutation is very important for carrier detection. The aim of this study was analysis of SMN1 mutation and determination of its frequency among Iranian patients. After genetic counseling and estimation of clinical symptoms of patients based on SMA consortium, molecular analysis based on PCR-RFLP has been performed. Frequency of consanguineous marriage in our study was 60%, while most of the patients were come from central and northern part of Iran. Of 243 families, 195 were categorized as type I, 30 as type II, and 18 as type III. Analysis of exon 7 deletion among families with live affected child showed that 94% of families with SMA type I, 95% in type II families and 100% in SMA type III had homozygous deletion. In prenatal diagnosis, twenty one of ninety two [22.8%] fetal samples were found to be affected and these pregnancies were terminated. The frequency of homozygous deletion of exon 7 of SMN1 was 94%. This is in agreement with Western Europe, China, Japan, and Kuwait

Expression of recombinant human serum albumin in the methylotrophic yeast; Hansenula polymorpha

Human serum albumin [HAS] is the major protein component of human plasma. It plays a very important role in transporting of macro molecules and maintaining the normal osmolarity. It is used as a therapeutical protein in patients with hypoalbuminemia and acute bleeding and burning. Albumin consumption in the world is about 500 ton/year. The aim of this research is to study the production of rHSA in shake flask culture by Hansenula polymorpha. H. polymorpha was used for the production of recombinant human serum albumin [rHSA] in several of shake flask culturing; expression of rHSA was investigated relating several parameters affecting the expression of HSA. To optimize the secretory expression of rHSA under the control of FMD promoter in H polymorpha RB-11 incubation time, culture media temperature and protease inhibitors were analyzed. This study not only established production of rHSA in yeast but also analyzed the correlation between affecting parameters and the level of HSA expression. Comparison of the HSA levels in the culture supernatants showed that the highest HSA yield was 17.6mg/l. The research shows that among three different temperatures [25°C,30°C and 37°C] 37°C was the best temperature and amongst three different incubation times [24h,48h and 72h] 48h was the optimum time and YNB 1% glycerol with buffer was the best derepression medium in comparison with others. Using these optimized conditions, stable production of rHSA of around 17.6mg/l was achieved. Our results suggest that affecting experssion factors improved in this study are suitable for production of recombinant albumin

novel mutation of SLC26A4 gene in an Iranian family with pendred syndrome

In the diagnosis of Pendred syndrome, assessment of individuals by molecular analysis of the SLC26A4 gene is recommended. Here we report a novel mutation in the SLC26A4 gene as revealed by denaturing high performance liquid chromatography [DHPLC] and DNA sequencing of the entire coding region of the SLC26A4 gene in five members of an Iranian family affected with Pendred syndrome. This is the first report of the molecular investigation of Pendred syndrome in Iran and the first report of the R79X mutation

[Spectrum of GJB2 gene mutations in nonsyndromic autosomal recessive deaf patients in Yazd]

Hearing loss is the most common sensory neural defect in humans, affecting 1 in 1000 neonates, with over half of these cases predicted to be hereditary in nature. Most hereditary hearing loss is inherited in a recessive fashion, accounting for approximately 80% of non-syndromic hearing loss [NSHL]. Mutations in GJB2 gene are major cause of inherited deafness in the European and American populations. To date, more than 90 mutations have been reported in this gene. Although most of these mutations are rare but 35delG mutation is the most common deafness causing allelic variant of GJB2 in most parts of t he world. In this project, 120 probands from 120 families with ARNSHL in Yazd Province were studied. Mutations Screening of GJB2 was performed by Amplification Refractory Mutation System [ARMS]-PCR for detection of 35delG and then all samples excluding 35delG homozygote were analyzed by DHPLC and Direct Sequencing. GJB2-related deafness was present in 7.5% of this population. We identified 4 mutations [35delG, 312del14, 314del14 and 167delT] and 4 polymorphisms [V153I, V27I, E114G and R127H] in this study. Prevalence of GJB2 mutations in this population was lower than American and European populations, and also other provinces of Iran. Interestingly, 312del14 rather than 35delG was the most common mutation found in the population under study. 56.25% of GJB2 mutant alleles carried 312del14 mutation. To date, this frequency has not been reported in any of the world populations

[Relative frequency of 35delG mutation in GJB2 gene in autosomal recessive non-syndromic hearing loss [ARNSHL] patients in Kerman population]

Congenital hearing loss with many genetic and environmental causes affects 1 in 1000 newborns. Mutations in the GJB2 [Gap Junction Beta-2] gene encoding the gap junction protein connexin 26 have been established as the main cause of autosomal recessive non-syndromic hearing loss. The aim of this stand was to study the frequency of one mutation [35delG] of GJB2 gene in Kerman non-syndromic deaf population. For this purpose, 130 chromosomes from 65 patients were studied and 35delG mutation was diagnosed in 3 [2.3%] chromosomes [one patient was homozygote and the other one was heterozygote]. This rate of frequency is significantly higher comparing to that in the whole population of Iran