Why is the novel Hb Miguel Servet visualised by CE-HPLC newborn and not by the CE-HPLC β-thalassaemia programme?

2020 ◽  
pp. jclinpath-2020-206812
Author(s):  
Valle Recasens ◽  
Ángeles Montañés ◽  
Carmen Rodríguez-Vigil ◽  
Yolanda González ◽  
Guillermo Hernández de Abajo ◽  
...  
Keyword(s):  
High Performance ◽  
Globin Genes ◽  
The Novel ◽  
Adequate Treatment ◽  
Zone Electrophoresis ◽  
Capillary Zone ◽  
Hb Variant ◽  
Unexpected Findings ◽  
Β Chain ◽  
Genetic Analyzer

Screening of haemoglobinopathies is indicated for the detection of sickle cell anaemia; thus, neonates can benefit from early and adequate treatment that prevents neurological damage, reduces morbidity and mortality associated with the disease. These types of programmes sometimes lead to unexpected findings. We present a new haemoglobin (Hb) variant (Hb Miguel Servet) detected by newborn screening. During neonatal screening of haemoglobinopathies by cation-exchange high-performance liquid chromatography (CE-HPLC) newborn, an Hb variant was detected. An analysis at 8 months of age using capillary zone electrophoresis (CZE) confirmed the presence of this new Hb. The molecular characterisation was performed by automatic sequencing of the α and β globin genes in an ABI PRISM 3100 Genetic Analyzer. Hb analysis by CE-HPLC β-thalassaemia short programmedid not indicate the presence of abnormal Hbs. By CZE showed a peak in the zone 12 zone comprising 3.3% of the total Hb. A new analysis by CE-HPLC on a Tosoh G8-2 (Horiba) shown a peak, in the region of HbA1b, did not interfere with the quantification of HbA1c. Sequencing of the β gene revealed the substitution of a guanine for a thymine (GGT >TGT) in codon 69 of the second exon, resulting in substitution of cysteine for the amino acid glutamine (HBB:c.208G>T). Hb Miguel Servet is a β-chain globin variant detected by CE-HPLC newborn (BioRad), by CZE and by CE-HPLC-CE Tosoh G8-2 (Horiba), but no by CE-HPLC-CE β-thalassaemia short programme (BioRad). In fact, for all the techniques that are visualised, what would be detected would be the glutathione variant of Hb (Miguel Servet).

Haemoglobinopathies that occur with decreased HbA2 levels: a gene mutation set involving the δ gene at a Spanish centre

2016 ◽  
Vol 70 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Ana Villegas ◽  
Fernando Ataúlfo González ◽  
Jorge M Nieto ◽  
Félix de la Fuente-Gonzalo ◽  
Rafael Martínez ◽  
...  
Keyword(s):  
High Performance ◽  
Globin Gene ◽  
Reversed Phase ◽  
Globin Genes ◽  
Reversed Phase Hplc ◽  
Structural Variants ◽  
Globin Chains ◽  
Zone Electrophoresis ◽  
Essential Parameter ◽  
Capillary Zone

AimsHaemoglobin A2 (HbA2) consists of two globin chains, α and β. Alterations in any of these genes influences the level of HbA2. Here, we present cases of structural Hb variants and thalassaemias which present either alone or together and reduce the level of HbA2 at varying degrees. Furthermore, we present a novel structural mutation in the δ globin gene, called Hb A2-Madrid.MethodsThe levels of HbA2 and HbF and the different haemoglobin variants were measured and analysed by ion exchange high performance liquid chromatography (HPLC, VARIANT II), the types of haemoglobins were determined by capillary zone electrophoresis (CZE) (Sebia) and the globin chains were determined by reversed-phase HPLC. Genetic analysis was performed by automatic sequencing of the α and δ genes as well as by multiple PCRs for the α globin genes.ResultsIn α thalassaemia (n=94), the HbA2 levels ranged from 1.39% to 2.43%. Among individuals with δ thalassaemia (n=5), the HbA2 level of those with δ+ thalassaemia was 1.77%, and that of those with δ0 thalassaemia was 1.70%. Among the individuals with δβ thalassaemia (n=13), those who were homozygous lacked HbA2. All structural haemoglobinopathies (n=97) were heterozygous; the α chain variants (n=84) presented with an HbA2 level of 1.76%, while the δ chain variants (n=13) presented with a level of 1.75%.ConclusionHbA2 is an essential parameter in the diagnostics of haemoglobinopathies. HPLC-EC and CZE allow the quantification of HbA2. Here, we show that quantification of HbA2 is critical for the identification of α, δ and βδ thalassaemias. Structural variants are discovered by HPLC. Molecular genetics is required for the proper identification of the mutations. Only with this knowledge is genetic counselling possible.

scholarly journals Incidental detection of a rare hemoglobin variant (Hemoglobin N Seattle) leading to undetectable levels of HbA1c in a diabetic female: a case report

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Sarita Pradhan ◽  
Sima Chauhan ◽  
Priyanka Samal
Keyword(s):  
High Performance ◽  
Glycosylated Hemoglobin ◽  
Chronic Complications ◽  
Zone Electrophoresis ◽  
Clinical Endocrinologist ◽  
Abnormal Hemoglobin ◽  
Capillary Zone ◽  
Assay Methods ◽  
Hb Variant ◽  
Rule Out

<p>Glycosylated hemoglobin (GHb) is routinely used to monitor glycemic control over past 2-3 months in diabetics. As per the recommendations of the American Association of Clinical Endocrinologist, 2007 values should be maintained below 7% to prevent the risk of chronic complications. We report a case of a 55-year old female patient with spuriously low HbA1c values by high-performance liquid chromatography. Suspecting the presence of any abnormal hemoglobin, capillary zone electrophoresis was done which identified the presence of Hb variant corresponding to -Hb N Seattle. Our case highlights that clinical laboratories should be aware of limitations of their HbA1c assay methods as well as rule out any possible interfering Hb variants.</p><p> </p><p>糖化血红蛋白(GHB)在糖尿病方面被常规用于监测过去2-3个月血糖控制。 根据美国临床内分泌医师学会2007年的建议，这个值应该被维持在7%以下，以防止慢性并发症的风险。 我们报告了一例55岁女性患者使用高效液体相色谱法测定假性低HbA1c值的病例。 因怀疑存在有某种异常血红蛋白，我们进行了毛细血管区带电泳，识别出存在对应于-Hb N Seattle的Hb变异体。 我们的病例强调了临床实验室应该意识到其HbA1c测定方法的局限性，并排除任何可能引起干扰的Hb变异体。</p>

scholarly journals High-performance capillary electrophoresis of core histones and their acetylated modified derivatives

1992 ◽  
Vol 283 (2) ◽  
pp. 467-471 ◽  
Author(s):  
H Lindner ◽  
W Helliger ◽  
A Dirschlmayer ◽  
M Jaquemar ◽  
B Puschendorf
Keyword(s):  
Capillary Electrophoresis ◽  
Capillary Zone Electrophoresis ◽  
Rat Liver ◽  
Phosphate Buffer ◽  
High Performance ◽  
Buffer System ◽  
Zone Electrophoresis ◽  
Core Histones ◽  
Capillary Zone ◽  
High Performance Capillary Electrophoresis

By using high-performance capillary electrophoresis, we have successfully separated rat liver core histones into several subfractions. Inconvenient interactions of the highly basic proteins with the capillary wall were eliminated by a phosphate buffer system containing 0.03% hydroxyprophylmethylcellulose. Sample amounts of a few nanolitres were analysed within about 20 min. Multiacetylated histones H4 and H3 from induced Friend erythroleukaemic cells prepurified by h.p.l.c. were clearly separated into their non-acetylated and distinct acetylated forms. Our results illustrate that the application of capillary zone electrophoresis on its own or in combination with h.p.l.c. to the analysis of histones provides an important new alternative to traditional gel electrophoreses.

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