Molecular Analysis of Xmn1-Polymorphic Site ´5 to G γ of the β -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 β 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 γ 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 γ -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 γ and 67 (95.7%) were (-/-) in Xmn1 '5 to G γ . In the controls, the (±) Xmn1 '5 to G γ was observed in only one individual (3.3%), aged 30. These findings possibly represent a new Saudi haplotype, [±] Xmn1 '5 to G γ . Our results demonstrate that most patients with SCD in Jazan have [-/-] Xmn1 with higher levels of Hb F and positive Xmn1 '5 to G γ normally associated with a low level of Hb F.