Association of hemoglobin E-Saskatoon with hemoglobin S: report of the first case found in Brazil

Hemoglobin Willamette (β51Pro → Arg): Case Report and Literature Review

We report a case of hemoglobin (Hb) Willamette (β51 Pro → Arg) in the Hematology Department of a tertiary hospital in Fortaleza, Northeast of Brazil. A literature review of the cases described in health sciences databases using as a descriptor Hb Willamette was performed, revealing 12 reported cases, of which only one presented with anemia. Herein, we describe a case of a female 29 years old, with hemoglobinopathy Willamette presenting clinically with anemia, having the lowest hemoglobin rate of the published cases. The relatives of the patient were evaluated andthe patient's mother corresponded to the first description of the association between Hb Willamette and HbC. Among the hemoglobinopathies, hemoglobin Willamette is an extremely rare disease; therefore it is important to analyze its clinical and laboratory manifestations for accurate diagnosis and assessment of potential interactions with other genetic variants.

High Frequency of Hb E-Saskatoon (HBB: c.67G > A) in Brazilians: A New Genetic Origin?

Hb E-Saskatoon [β22(B4)Glu→Lys, HBB: c.67G > A] is a rare, nonpathological β-globin variant that was first described in a Canadian woman of Scottish and Dutch ancestry and has since then been detected in several populations. The aim of the present study was to identify the origin of Hb E-Saskatoon in Brazil using β-globin haplotypes and genetic ancestry in carriers of this hemoglobin (Hb) variant. Blood samples were investigated by isoelectric focusing (IEF) and high performance liquid chromatography (HPLC) using commercial kits. Hb E-Saskatoon was confirmed by amplification of the HBB gene, followed by sequence analysis. Haplotypes of the β-globin gene were determined by polymerase chain reaction (PCR), followed by digestion with specific restriction enzymes. Individual ancestry was estimated with 48 biallelic insertion/deletions using three 16-plex PCR amplifications. The IEF pattern was similar to Hbs C (HBB: c.19G > A) and Hb E (HBB: c.79G > A) [isoelectric point (pI): 7.59-7.65], and HPLC results showed an elution in the Hb S (HBB: c.20A > T) window [retention time (RT): 4.26-4.38]. DNA sequencing of the amplified β-globin gene showed a mutation at codon 22 (GAA>AAA) corresponding to Hb E-Saskatoon. A total of 11 cases of this variant were identified. In nine unrelated individuals, Hb E-Saskatoon was in linkage disequilibrium with haplotype 2 [+ - - - -]. All subjects showed a high degree of European contribution (mean = 0.85). Hb E-Saskatoon occurred on the β-globin gene of haplotype 2 in all Brazilian carriers. These findings suggest a different genetic origin for this Hb variant from that previously described.