[Detection of beta-thalassemia mutations in Kurd patients of Kurdistan and West Azerbaijan provinces]

Beta-thalassemia is the most common autosomal recessive disorder. More than 200 different mutations in the beta-globin gene have been detected which can lead to decreased or absent beta-globin chain synthesis. Since the Iranian Population is a mixture of different ethnic groups, it is necessary to determine the frequency and distribution of these mutations in the different ethnic groups of our county. Therefore, in this study we determined the Spectrum and the frequency of beta-thalassemia mutations in the patients with beta-thalassemia major in the Kurd population of Kurdistan and West Azerbaijan provinces of Iran. To detect mutations, extracted DNA of 110 chromosomes from 55 unrelated patients, were studied by PCR-ARMS [Polymerase Chain Reaction-Amplification Refractory Mutation System] SSCP [Single Strand Conformation Polymorphism] and direct sequencing methods. The results of this study showed that IVS-II-1 [G-A] was the most common mutation with a frequency of 31%; FSC 8/9[+G] with a frequency of 19% was the second most prevalent mutation among all chromosomes. Other mutations were IVS-I-1[G-A] FSC8 [-AA] IVS-I-110[G-A] FSC36/37[-T] IVS-I-5[G-C], IVS-I-128[T-G] FSC44 [-C], FSC 5[-CT] and +22UTR [G-A] These mutations comprised 79% of beta-thalassemia mutations in this region and 21% of the mutations still remains to be explored. The results of this study showed that, there are similarities and differences between this region and other parts of Iran and also neighboring countries. Therefore, determination of beta-thalassemia mutations in this region seems to be necessary and beneficial for designing prenatal diagnosis programs

[Genetic assessment of chromosome 21 microsatellites and their application in the diagnosis of down syndrome patients within an Eastern Azarbayjan population]

Down syndrome is one of the most common chromosome aneuploidies causing mental retardation which occurs in approximately 1/230 pregnancies. It is usually caused by the presence of an extra chromosome 21. The aim of this study was to evaluate the simple PCR based DNA diagnostic method and also to determine the parental origin of the extra chromosome 21 in trisomal Down syndrome. To determine the polymorphism rates of chromosome 21 microsatellite markers, 50 people from Eastern Azarbayjan were randomly selected and studied for the microsatellites. The results were statistically analyzed. Thirty affected Down syndrome patients, diagnosed by specialists were referred to the lab for further molecular analysis. After genetic counseling and getting consent, blood samples were obtained. Seven pairs of chromosome 21 microsatellite markers were amplified using PCR in all the samples. Five highly polymorphic microsatellite markers were selected from a total seven markers, studied in 50 normal people. Out of 30 Down syndrome's patients, trisomal 21 was diagnosed in 21 families [70%]. In which non-disjunction errors were determined to be of maternal origin in 86% and of paternal origin in 9% of the cases. The mean maternal and parental age was 33/3 and 36/2, respectively. The three microsatellite markers, D21S1910, D21S1411 and D21S11 could diagnose a high percentage of trisomal 21 in Down syndrome' patients. The parental origin of an extra copy of chromosome 21 could be exactly determined