Dr. B. Zarbakhsh, E. Farshadi, A. Ariani Kashani, Dr. M. Karimipoor, Dr. A. Azarkeivan, R. Habibi Pourfatideh, Dr. M.s. Fallah, Dr. F. Maryami, A.r. Kordafshari, Z. Kaeini Moghadam, Dr. H. Bagherian, Dr. S. Zeinali,
Volume 7, Issue 2 (Summer 2010)
Abstract
Background and Objectives
There is a large number of couples who are considered potential carriers of alpha or beta-thalassemia. The exact determination of gene defect for thalassemia carriers is essential for premarital screening genetic counseling. In this study, we conducted a molecular study of those suspected of carrying alpha-thalassemia mutated genes in order to detect potential deletional and non-deletional mutations in the alpha globin gene cluster.
Materials and Methods
In this study, those suspected of having mutation in alpha-globin gene cluster with MCV < 80 fl, MCH < 27 pg, normal serum iron, and HbA2 were selected from those referred to Pasteur Institute of Iran. Four common deletional mutations and non-deletional mutations were studied using multiplex gap-PCR, ARMS-PCR, and direct sequencing.
Results
One hundred and forty samples with above criteria entered the study with 126 (90%) cases showing at least one mutation. Study of 4 common deletional mutations using multiplex gap-PCR revealed at least one deletion in 99 (70.71%) cases. Non-deletional mutations were found using ARMS-PCR or direct sequencing in 27 (19.28%) cases. Nine different mutations were found in the samples with –α3.7 being the most common deletion in 100 (35.71%) alleles out of 280 studied chromosomes followed by -α5nt in 25 (8.93%) alleles as the next most common.
Conclusions
We used direct sequencing to characterize more suspected carriers of alpha thalassemia. However, using other methods like real-time PCR and multiplex ligation-dependent probe amplification (MLPA) for gene dosage study of alpha-globin gene cluster could help find other non-common deletions.
Key words :
Abstract
Background and Objectives
There is a large number of couples who are considered potential carriers of alpha or beta-thalassemia. The exact determination of gene defect for thalassemia carriers is essential for premarital screening genetic counseling. In this study, we conducted a molecular study of those suspected of carrying alpha-thalassemia mutated genes in order to detect potential deletional and non-deletional mutations in the alpha globin gene cluster.
Materials and Methods
In this study, those suspected of having mutation in alpha-globin gene cluster with MCV < 80 fl, MCH < 27 pg, normal serum iron, and HbA2 were selected from those referred to Pasteur Institute of Iran. Four common deletional mutations and non-deletional mutations were studied using multiplex gap-PCR, ARMS-PCR, and direct sequencing.
Results
One hundred and forty samples with above criteria entered the study with 126 (90%) cases showing at least one mutation. Study of 4 common deletional mutations using multiplex gap-PCR revealed at least one deletion in 99 (70.71%) cases. Non-deletional mutations were found using ARMS-PCR or direct sequencing in 27 (19.28%) cases. Nine different mutations were found in the samples with –α3.7 being the most common deletion in 100 (35.71%) alleles out of 280 studied chromosomes followed by -α5nt in 25 (8.93%) alleles as the next most common.
Conclusions
We used direct sequencing to characterize more suspected carriers of alpha thalassemia. However, using other methods like real-time PCR and multiplex ligation-dependent probe amplification (MLPA) for gene dosage study of alpha-globin gene cluster could help find other non-common deletions.
Key words : alpha-Thalassemia, mutation, PCR, Iran