A Rare Hb H Disease Due to the – –^SEAand 16.6 kb α-Thalassemia-2 Deletions

Scanning for α‐Hemoglobin Variants by High‐Resolution Melting Analysis

“…Common hemoglobin variants, such as Hb CS, and Hb E, based on the position of their respective peaks in the above Hb‐typing technique(s), were confirmed using amplification refractory mutation system (ARMS) PCR method . Samples containing uncommon α‐Hb variants were identified by DNA sequencing using α1‐ and α2‐globin specific sequencing primers as described previously .…”

Isothermal Strand-Displacement Polymerase Reaction for Visual Detection of the Southeast Asian–Type Deletion of α-Thalassemia

“…SEA-type a-thalassemia was detected by conventional gap-PCR followed by gel electrophoresis as described previously. 7,9,10 Genomic DNA was denatured by heating at 95 C in a water bath for 5 minutes and immediately chilled on ice for 10 minutes.…”

“…4 The most common type of a-thalassemia in Asian populations, termed the Southeast Asian (SEA) type, is caused by a deletion of approximately 20.5 kb 5,6 ; this genotype comprises approximately 95% of a-thalassemia genotypes together with the a 3.7 and a 4.2 types and can result in a fatal condition in the fetus known as Hb Bart hydrops fetalis when the deletion is homozygous. 7 The mother of the fetus has an increased risk of serious complications, including polyhydramnios, preeclampsia, ante-or postpartum hemorrhage, and difficult vaginal delivery. 8 Therefore, a diagnostic assay to determine the SEA type of a-thalassemia deletions is important for genetic consultation and prenatal diagnosis.…”