Molecular Study of Deletional and Nondeletional Mutations on the α-Globin Locus in the Azeri Population of Northwestern Iran.

The aim of this study was to determine the molecular spectrum and frequency of deletional and nondeletional α-thalassemia (α-thal) mutations and the genotype-phenotype correlation in common mutations in the Azeri population of Northwestern Iran. A total of 1256 potential carriers with microcytic and hypochromic anemia and normal Hb A2 levels (<3.5%) and without iron deficiency anemia plus three fetuses were identified. Multiplex gap-polymerase chain reaction (gap-PCR) and sequencing for α-thal mutations were carried out. In 606 individuals, the α-globin gene was normal, but in 650 persons (51.6%) and three fetuses, 10 different mutations were detected. The most frequent deletional genotypes were as follows: αα/-α3.7 (61.7%), -α3.7/-α3.7 (11.9%), αα/-α4.2 (4.6%), αα/- -MED (4.3%) and αα/-(α)20.5 (3.8%). The most frequent nondeletional genotypes were αα/αIVS-I (-5 nt)α (HBA2: c.95+2_95+6delTGAGG) and αα/αPoly A2α [polyadenylation signal (polyA2) (AATAAA>AATGAA); HBA2: c.*96G>A] with frequencies of 1.08% and 0.92%, respectively. Meanwhile, 7.71% of individuals with a proven ß-thalassemia (ß-thal) mutation were found to also carry an α-thal mutation. Persons having two functional α-globin genes showed lower mean corpuscular volume (MCV) and mean corpuscular hemoglobin (Hb) (MCH) values compared to those with one mutated α-globin gene, provided that they had normal ß-globin genes. Overall, the incidence of α-thal was 2.7% in the Azeri population in Northwestern Iran. Our results showed that the variability of α-thal mutations are high in the Azeri population and that α-thal mutations are highly heterogeneous in both deletional and nondeletional genotype aspects.

Childhood cancer in Iran.

This study tries to define the incidence, survival, and risk factors of childhood cancer in Iran. A literature review on published articles was conducted by using different search engine from November 1974 to October 2008. The incidence rate of childhood cancer in Iran was 48 to 112 and 51 to 144 per million among girls and boys in multi geographical settings, respectively. The most common cancer in children from 0 to 14 years old were leukemia (incidence rate=8 to 62/million), lymphoma (3 to 23), and central nervous system tumors (3 to 22). The mortality rate of childhood cancers was 42 and 49 per million among girls and boys, respectively in 2004. A positive association between ABO blood groups, family history of cancer, drug usage during pregnancy, fathers' job, history of radiation, and parental smoking habit were found with childhood leukemia. It is essential that the effect of geographical differences on childhood cancer incidence rates and high mortality rate to be investigated in future studies.