Molecular Analysis of Xmn1-Polymorphic Site ' 5 to G gamma of the beta-Globin Gene Cluster in a Saudi Population of Jazan Region in Correlation with Hb F Expression

The southern part of Saudi Arabia has an ethnically diverse population where sickle-cell anemia (sickle cell disease) is common, but little is known about its beta s haplotypes. The goal of the current study is to ascertain the prevalence of the Hb S gene with analysis of Xmn1 ' 5 to G gamma haplotype among the Saudi population in the Jazan area. Initially recorded findings of (1) Hb S gene and (2) hematological parameters with Hb F levels were collected from 5990 participants. Then, the second series of 70 different patients with established sickling disease and 30 healthy individuals as a control group was recruited, in which the genotype of Xmn1 ' 5 to G gamma-SNP was performed by PCR-RFLP. In the first series, the prevalence of Hb types was AA at 86.8% (N = 5198), AS at 12.4% (N = 745), and SS at 0.8% (N = 47). Of the second series, three patients (4.3%) were (+/-) Xmn1 ' 5 to G gamma and 67 (95.7%) were (-/-) in Xmn1 ' 5 to G gamma. In the controls, the (+/-) Xmn1 ' 5 to G gamma was observed in only one individual (3.3%), aged 30. These findings possibly represent a new Saudi haplotype, [+/-] Xmn1 ' 5 to G gamma. Our results demonstrate that most patients with SCD in Jazan have [-/-] Xmn1 with higher levels of Hb F and positive Xmn1 ' 5 to G gamma normally associated with a low level of Hb F.