Hemoglobin variants recently detected in Austria

Measurement of glycated hemoglobin (HbA_1c) is used for routine management of diabetic patients. Glucose linkage to HbA_1c reflects mean blood glucose levels during the last 3 months before examination. Various methods for HbA_1c determination show abnormal values with hemoglobin variants. In some diabetic patients excessively high HbA_1c values with high-performance liquid chromatography (HPLC) led to the detection of Hb Graz. In addition to Hb Graz, other silent hemoglobin variants have been found in Austria. Here we review Hb Graz, Hb Sherwood Forest, and Hb Okayama detected while using HPLC for the measurement of HbA_1c in diabetic patients.     

The Assessment and Sustainable Management of Sickle Cell Disease in the Indigenous Tharu Population of Nepal

Sickle cell disease is an inherited hemoglobinopathy associated with significant morbidity and mortality. Reports suggest a high sickle cell disease burden among the indigenous Tharu population of Nepal, who for centuries have inhabited regions where malaria is endemic. Unfortunately, health care resources are limited and often inaccessible for Tharu individuals suffering from sickle cell disease. We conducted a large-scale screening effort to estimate the prevalence of Hb S (HBB: c.20A>T) among the Tharu population and delivered community-based education sessions to increase sickle cell disease awareness. A total of 2899 Tharu individuals aged 6 months to 40 years in the rural district of Dang in Western Nepal were screened using a sickling test, of whom, 271 [9.3%; 95% confidence interval (95% CI): 8.3–10.4%] screened positive for Hb S. Those who screened positive were offered diagnostic gel electrophoresis testing. Of the 133 individuals who underwent diagnostic testing, 75.9% (n?=?101) were confirmed to be Hb AS heterozygotes, 4.5% (n?=?6) were confirmed to be Hb SS homozygotes and 19.5% (n?=?26) were false positives. These findings support a large burden of sickle cell disease among the Tharu population and highlight the importance of appropriate resource allocation and management. With a positive predictive value of 80.0% (95% CI: 73.0-87.0%), the sickling test in conjunction with raising local sickle cell disease awareness may be a simple and sustainable way to promote access to health resources.     

Benign sickle cell disease in Saudi Arabia: survival estimate and population dynamics

A survey of 8,084 adult Saudi male employment applicants yielded 872 with the sickle cell trait (AS) and 51 with sickle cell disease. Based on the known distribution of hemoglobin S genes between oasis and non-oasis populations in Saudi Arabia, and on calculation of the expected number of abnormal homozygotes within the non-oasis and oasis subgroups as well as the entire employment applicant group, it appears that virtually 100% of Saudis with SS disease survive to adult life. Saudi Arabs and other Caucasian populations in the Middle East exhibit a benign type of SS disease as compared with Blacks in Africa and the Americas. In the Middle East, gene contributions from SS individuals will shift equilibrium frequencies to higher levels than encountered in Black populations under sustained selective pressures, and the polymorphism will tend to be stable with decline in selective pressure. There are some indications that the hemoglobin S gene may have been a recent import into the Middle East.     

海口地区1201例血红蛋白病筛查及基因检测的结果

目的 了解海口地区人群血红蛋白病的主要类型,为地中海贫血防控和医学研究提供有益的数据资料.方法 采用毛细管电泳法筛查血红蛋白病,Gap-PCR、PCR-RDB技术检测地贫表型阳性人群3种缺失型、3种非缺失型α-地贫;17种β-地贫.结果 1201例血红蛋白电泳病例,检出309例异常,阳性率25.73％,α-地贫表型阳性病例数最多,占总异常病例数70.87％,地贫外的异常血红蛋白病例占2.27％.经确诊,α-地贫检出12种基因型,--SEA/αα、-α 3.7/αα、-α4.2/αα三种基因型病例为主,β-地贫检出7种异常基因型,CD41-42/N、IVS-Ⅱ-654/N为主.结论 海口地区血红蛋白病以地贫,特别是α-地贫为主,应重视地贫防控,推广血红蛋白电泳技术.     

Hb Alcorn County: A β-Globin Variant [β40(C6)Arg→Thr; HBB: c.122G>C (p.Arg41Thr)] with Increased Oxygen Affinity

Abstract

We describe Hb Alcorn County, a heterozygous hemoglobin (Hb) variant, in a 6-month-old Hispanic male and his mother. DNA sequencing demonstrated a mutation on the HBB gene [β40(C6)Arg→Thr; HBB: c.122G>C (p.Arg41Thr)], predictive of a substitution of arginine to threonine at position 40 of the β-globin protein. This amino acid substitution involves the α1β2 contact and occurs at the same position as Hb Austin [β40(C6)Arg→Ser; HBB: c.[123G>C or 123G>T] (p.Arg41Ser)] and Hb Athens-GA [β40(C6)Arg→Lys; HBB: c.122G>A (p.Arg41Lys)], both of which show increased oxygen affinity.     

Genotypic and phenotypic heterogeneity of African Americans with primary iron overload

Primary iron overload may be relatively common in African Americans, but its cause is incompletely understood. Thus, we evaluated genotype and phenotype characteristics of unselected African American index patients with primary iron overload who reside in central Alabama. All had hepatic iron concentration > or =30 micromol/g dry wt or > or =2.0 g of iron mobilized by phlebotomy to achieve iron depletion. Genotype analyses were performed in African American control subjects from the same region. There were 23 patients (19 men, 4 women); mean age at diagnosis was 52 +/- 12 years (1 SD) (range 32-69 years). Nine (39.1%) reported that they consumed > or =45 g of ethanol daily; five had chronic hepatitis C. Eight had some form of hemoglobinopathy or thalassemia. Mean serum transferrin saturation was 56 +/- 28% (range 15-100%). The geometric mean serum ferritin at diagnosis was 1076 ng/mL [95% confidence interval 297-3473 ng/mL]. Increased stainable liver iron was observed in hepatocytes only in 4 patients, in macrophages only in 8 patients, and in hepatocytes and macrophages in 8 patients. The mean quantity of iron mobilized by phlebotomy (corrected for iron absorbed during treatment) was 5.3 +/- 2.0 g (range 4.0-8.4 g). Iron removed by phlebotomy was greater in patients with hemoglobinopathy or thalassemia than in those without these forms of anemia (6.6 +/- 1.3 g vs 3.9 +/- 1.6 g, respectively; P = 0.0144). Daily consumption of > or =45 g of ethanol or chronic hepatitis C was not associated with an increased or decreased amount of phlebotomy-mobilized iron, on the average. The percentage of index patients positive for HFE C282Y was greater than that of controls (P = 0.0058). The respective percentages of phenotype positivity for HFE H63D, D6S105(8), and HLA-A*03 were similar in patients and controls. HFE S65C, I105T, and G93R were not detected in index or control subjects. Two of 13 patients were heterozygous for the ferroportin allele nt 744 G-->T (Q248H), although the phenotype frequency of this allele was similar in patients and 39 controls. Synonymous ferroportin alleles were also detected in some patients. The ceruloplasmin mutation nt 1099C-->T (exon 6; Arg367Cys) was detected in 1 of 2 patients tested. Abnormal alleles of beta-2 microglobulin, Nramp2, TFR2, hepcidin, or IRP2 alleles were not detected in either of the 2 patients so tested. We conclude that primary iron overload in African Americans is not the result of the mutation of a single gene. HFE C282Y, ferroportin 744 G-->T, and common forms of heritable anemia appear to account for increased iron absorption or retention in some patients.     

血红蛋白四川〔α87(F8)His→Pro〕——一种新的慢速不稳定血红蛋白

本文报告了在四川省重庆地区发现的一种新的血红蛋白变型,其电泳迁移位置在HbG前,含量为16.5％,家系中有3名成员具有这种异常的Hb,但无明显的临床症状。结构分析证明其α链N端第87位的组氨酸被脯氨酸替代,表示为[α87(F8)His→Pro],并按其发现省份命名为血红蛋白四川(Hb Sichuan)。     

Hb SE disease: a clinico-hematological profile

Hb S and Hb E are globally common hemoglobinopathies. However, Hb SE double heterozygous state is uncommon, with only 25 cases reported so far in literature. We present two more cases. One presented with gallstones, and the other was asymptomatic. This type of disorder was previously described as a relatively asymptomatic condition compared to HbSS. A review of the 25 reported cases in literature shows that 40.7% (11/27) of these cases are symptomatic. Gender, hematological parameters and levels of Hb S, E or F do not predict clinical severity.