بررسی مولکولی جهش های غیر حذفی ژن های آلفاگلوبین بیماران آلفا تالاسمی دراستان کرمانشاه

  Background: Alpha thalassemia is a single gene disorder, inherited in an autosomal recessive manner. The thalassemia occurs mostly in peoples from the Mediterranean to Southeast Asia. The present study was aimed to identify the prevalence of nondeletional Alpha thalassemia mutations in our samples in the Kermanshah province.   Methods : This study included Alpha thalassemia individuals who had referred to Medical Genetics Laboratory, Kermanshah University of Medical Sciences, Kermanshah, Iran, between March 2009 and February 2011. Subjects were from different geographic areas of Kermanshah province in the west of Iran.   Forty patients were selected upon having red cell indices suggestive of non deletional alpha thalassemia carrier status (MCV<80 fl and MCH<27pg, normal or slightly reduced HbA2 and HbF) after ß- thalassemia, iron deficiency and deletional Alpha thalassemia were excluded. Blood samples were collected, and genomic DNA was extracted from peripheral blood leucocytes by salting out procedure. DNA analyses were performed using Amplification Refractory Mutation System (ARMS). Sequence analysis was applied for DNA samples when no mutation was detected with ARMS.   Results: Six different types of mutations were determined in 39 subjects of 40 individuals.   The most common Alpha-thalassemia mutation is αpolyA4 which comprises 37.5% of the total mutations, followed by α-5nt (35%) and αpolyA6 (17.5%).   DNA sequencing of the amplified a-globin genes revealed Hb Adana, Alpha1+1mRNA and alpha2+ 8 32 (G>A) point mutations.     Conclusions: This is the first comprehensive study in this region. The results of the study can be also applied for the genetic counseling, population screening and prenatal diagnosis.