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Beta-Thalassemia (thal) is one of the most common autosomal recessive disorders in Iran. There are more than two million carriers of beta-thal and over 15,000 people affected with beta-thal major who live in Iran. Prevalent mutations were identified by examining genomic DNAs isolated from 392 blood samples of beta-thal carriers from three northern provinces of Iran. Furthermore, 172 pregnant women were analyzed from the 196 couples who requested pregnant diagnosis for beta-thal. Allele identification was carried out using routine reverse dot-blot, amplification refractory mutation system (ARMS), and genomic sequencing. The most common mutation, IVS-II-1 (GA), is followed, in order of frequency, by codon 30 (GC), frameshift codons (FSC) 8,9 (+G), FSC 22/23/24 (-AAGTTGG), IVS-I-110 (GA), IVS-I-5 (GC), IVS-II-745 (CG), IVS-I-2 (TC), FSC 8 (-AA), IVS-I,3'-end (-25 bp), IVS-I-1 (GA), FSC 36/37 (-T), IVS-I-6 (TC), FSC 5 (-CT), -28 (AC), codon 37 (GA), IVS-II-2,3 (+11/-2), -30 (TA), and -88 (CA). We have also revealed the existence of five new mutations from northern Iran, one of which (codon 37) is the first reported for Iran. Furthermore, the rate of unknown mutations is significantly reduced in our study (about 6%). These results could help with establishing a center for prenatal diagnosis, prevention, and control of thalassemia in the northern provinces of Iran.

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Mitochondria have essential role in cellular energy metabolism and defects in their function lead to many metabolic diseases. Mitochondrial DNA (mtDNA) mutations have been associated with number diseases such as nonsyndromic and aminoglycoside-induced hearing loss. Mutational screening of entire 12SrRNA and tRNA (ser (UCN)) genes in 107 unrelated Iranian patients with amino glycoside-induced and nonsyndromic bilateral hearing loss by direct sequencing analysis method were performed. Twenty different homoplasmic sequence variants were identified; including fifteen common polymorphisms, two putatively pathogenic variants: m.921T>C and m.1005T>C, one 12SrRNA sequence variant m.739C>T and two nucleotides substitution; m.1245T>C and m.1545T>C. Deafness-associated mutation, m.1555A>G, was not found. In our patients we found the mutation 1005 was associated with R haplogroup. These finding show that m.1555A>G mutation is not important in our population. Nucleotide change, m.739C>T, previously reported with very low frequency. We suggested the variation of two nucleotides 1245 and 1545 that localized at conserved site of 12SrRNA may be new candidate for amino glycoside-induced and nonsyndromic hearing impairment associated mutations. However, aminoglycoside exposure is a risk factor for clinical phenotype appearance of these mutations.

Preimplantation genetic diagnosis (PGD) has been considered as an alternative to prenatal diagnosis for prevention of genetic disorders while avoiding the subsequent termination of pregnancy. However, the limited amount of template DNA available in a single diploid cell used for PGD leads to number of problems including an increased incidence of detectable contamination; amplification failure and allele drop out. Due to their highly polymorphic and amplifiable characteristics, short tandem repeat (STR) analysis has been proposed as a mean to overcome these limitations. Heterozygosity of the applied STRs is of paramount importance in their informativity, and should therefore be studied in any certain population. Here, for the first time, we report on the heterozygosity analysis of five STR markers (D5S1408, D5S1417, D5S610, D5S629 and D5S637) flanking to SMA gene region, to examine their applicability in the PGD for SMA disease. We have also investigated other statistical features of these markers and found that all of the five studied STRs were informative and four meet the Hardy-Weinberg equilibrium for the studied population. Furthermore, our results propose that similar approaches can be used for the PGD of other single gene disorders.

Glioblastoma multiform (GBM; World Health Organization (WHO) grade IV) and anaplastic astrocytomas (AA; WHO grade III) are highly aggressive and lethal astrocytic brain tumors. To detect cancer-specific somatic mutations in two hot-spot regions of PIK3CA gene, the helical and kinase domains (encoded by exons 9 and 20, respectively) in GBM and AA, the authors examined the respective sequences 31 paraffin-embedded samples (23 GBM and 8 AA). The samples were obtained from a group of Iranian patients affected with high-grade glioblastoma (HGG). The overall prevalence of PIK3CA mutations was 23% (7/31) for both tumor types (22% in GBM, and 25% in AA). Five mutations were detected in exon 20, p.Arg992Gln (c.2976G→A), p.Met1005Val (c.3014A→G), p.Ile1019→Val (c.3056A→G), p.Ser1008Cys (c.3024C→G), and p.Asn1044Asp (c.3130A→G), and one mutation in exon 9, p.Glu545Ala (c.1634A→C). Additionally exons 4-8 of P53 gene in four unrelated young patients, who showed no mutations in PIK3CA exons 9 and 20, were analyzed. Three mutations were identified: p.Pro72Ala (c.214C→G), g.11608G→T (homozygote splice mutation), and p.Thr170Thr (c.510G→A silent mutation). In conclusion, mutation detection in PIK3CA in patients with a high degree of malignancy and early age at diagnosis should be included in molecular diagnostic protocols, also with regard to possible upcoming therapies.

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Introduction: Childhood-onset proximal spinal muscular atrophies (SMAs) are an autosomal recessive, clinically heterogeneous group of neuropathies characterised by the selective degeneration of anterior horn cells. SMA has an estimated incidence of 1 in 10,000 live births. The causative genes are survival motor neuron (SMN) gene and neuronal apoptosis inhibitory protein (NAIP) gene. Deletions of the telomeric copy of SMN gene (SMN1) have been reported in 88.5% to 95% of SMA cases, whereas the deletion rate for NAIP gene (NAIP) is between 20% and 50% depending on the disease severity. The main objective of this study was to genetically characterise the childhood onset of SMA in Iran. Materials and Methods: Molecular analysis was performed on a total of 75 patients with a clinical diagnosis of SMA. In addition to common PCR analysis for SMN1 exons 7 and 8, we analysed NAIP exons 4 and 5, along with exon 13, as a internal control, by bi-plex PCR. Results: The homozygous-deletion frequency rate for the telomeric copy of SMN exons 7 and 8 in all types of SMA was 97%. Moreover, exons 5 and 6 of NAIP gene were deleted in approximately 83% of all SMA types. Three deletion haplotypes were constructed by using SMN and NAIP genotypes. Haplotype A, in which both genes are deleted, was seen in approximately 83% of SMA types I and II but not type III. It was also found predominantly in phenotypically severe group with an early age of onset (i.e., less than 6-month-old). We also report 34 of our prenatal diagnosis. Conclusions: To our knowledge, the present study is the first one giving detailed information on SMN and NAIP deletion rates in Iranian SMA patients. Our results show that the frequency of SMN1 homozygous deletions in Iran is in agreement with previous studies in other countries. The molecular analysis of SMA-related gene deletion/s will be a useful tool for pre- and postnatal diagnostic. Key words: Deletion analysis, Iran, NAIP gene, Prenatal diagnosis, Spinal muscular atrophy, SMN gene