rs281864895
This variant is located in the HBA1 gene.
▶ClinVar annotation
▶Research that mentions this SNP (1)
▶Hb adana or α259(E8)Gly→Aspβ2, A severely unstable α1‐globin variant, observed in combination with the ‐(α)20.5 KB α‐thal‐1 deletion in two Turkish patientsCase reportN=36Cürük MA et al.(1993)· American Journal of Hematology
This study analyzed α-globin gene mutations in 36 Malaysian patients (26 with α-thalassemia intermedia and 10 with Hb Adana trait) carrying the Hb Adana variant (HBA2: c.179G>A, p.Gly60Asp). All 36 samples (100%) had the mutation located on the α2-globin gene rather than α1, with 66.7% showing the α3.7/αCd59α genotype. The finding differs from Turkish cases where Hb Adana is located on α1, suggesting distinct geographic origins for this α-thalassemia variant in Southeast Asia versus Turkey.
About HBA1
The human alpha globin gene cluster located on chromosome 16 spans about 30 kb and includes seven loci: 5'- zeta - pseudozeta - mu - pseudoalpha-1 - alpha-2 - alpha-1 - theta - 3'. The alpha-2 (HBA2) and alpha-1 (HBA1) coding sequences are identical. These genes differ slightly over the 5' untranslated regions and the introns, but they differ significantly over the 3' untranslated regions. Two alpha chains plus two beta chains constitute HbA, which in normal adult life comprises about 97% of the total hemoglobin; alpha chains combine with delta chains to constitute HbA-2, which with HbF (fetal hemoglobin) makes up the remaining 3% of adult hemoglobin. Alpha thalassemias result from deletions of each of the alpha genes as well as deletions of both HBA2 and HBA1; some nondeletion alpha thalassemias have also been reported. [provided by RefSeq, Jul 2008]
View all HBA1 variants →Gene information from NCBI Gene. Variant classifications from ClinVar.
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