Alpha-globin Gene Research Articles

Regulatory systems of chicken alpha-globin gene domain suppress bidirectional transcription

• The RFP inserted into chicken a-globin gene cluster is transcribed only when it is inserted in the same direction as globin genes. • Insertion of RFP into chicken a-globin gene cluster opposite to the dirtection of globin genes suppresses their transcription. • Expression of NPRL3 gene located upstream to a-globin gene cluster is not affected by insertion of RFP into the cluster

The Use of Next-generation Sequencing in the Diagnosis of Rare Inherited Anaemias: A Joint BSH/EHA Good Practice Paper.

The Use of Next-generation Sequencing in the Diagnosis of Rare Inherited Anaemias: A Joint BSH/EHA Good Practice Paper.

Genetic Analysis of Alpha-Thalassemia Mutations in Thi-Gar Province, Iraq.

The prevalence of alpha-thalassemia as a major health problem in the south of Iraq has highlighted the necessity of investigations and screening of patients with thalassemia. The present study aimed to characterize the spectrum of alpha-globin gene mutations in patients who were followed up in a genetic diseases center in Thi-Qar province. A total of 30 subjects were collected from thalassemia patients and 15 cases as the control group. Polymerase chain reaction (PCR) and direct sequencing were performed for functionally regions of the gene (exon 1 and exon 2). The fragment size amplified was 442 bp in the Exon 1 region and 324 bp in the Exon 2 region of α-globin. The molecular analysis of the sequence of PCR products revealed that 13 point mutation within the α-thalassemia gene included deletion and substitution mutation, while the rest of the mutations were in the intron site of the gene. These results indicated that mutations may constitute a risk of developing hemophilia B disease. Molecular mechanisms in the expression of globin genes are used to help manage patients with thalassemia.

A Common Alpha Globin Gene Deletion is Associated with Decreased Arterial Alpha Globin Gene Expression and Altered Vasoreactivity among Black Americans

Alpha globin binds to endothelial nitric oxide (NO) synthase (eNOS) and limits the diffusion of NO from endothelial cells into vascular smooth muscle. Previously, we demonstrated that pharmacologic disruption of alpha globin‐eNOS binding enhanced NOS‐dependent vasodilation in human arteries. Here, we explore the hypothesis that individuals with alpha globin gene deletions will have reduced alpha globin gene expression in resistance arteries and altered arterial vasoreactivity.To test this hypothesis, we screened healthy Black Americans (clinical trial # 02692872) for a common 3.7 kb gene deletion in the alpha globin gene locus (HBA) that reduces the number of functional gene copies. We excluded people with risk factors for cardiovascular disease and created a nested case control study that included 15 people with four copies, 8 people with three copies, and 2 people with two copies of HBA. Each individual underwent an incisional subcutaneous adipose biopsy (clinical trial # 03937817), from which we isolated resistance arteries less than 200 μm in diameter. Resistance arteries were cannulated and perfused free of blood before undergoing multiphoton imaging, gene expression analysis, or pressure myography.Multiphoton imaging of adipose resistance arteries revealed alpha globin to co‐localize with eNOS near the myoendothelial junction between endothelial and smooth muscle cells. Arteries from individuals with three functional copies of HBA had lower expression of HBA compared to arteries from individuals with four functional copies of HBA(1715 copies/ng cDNA vs 1176 copies/ng cDNA, p = 0.03). The concentration of phenylephrine required to constrict the human adipose arteries to 50% of baseline was 8 times greater for arteries from subjects with three copies of HBA compared to arteries from subjects with four copies of HBA (log10[EC50]: ‐4.78 (95% CI: ‐4.29 to ‐5.22) vs ‐5.68 ± (95%CI: ‐5.33 to ‐5.98) p = 0.003). Arteries from individuals with three copies of HBA also had reduced maximal constriction to phenylephrine compared to subjects with four copies of HBA(p < 0.01).These results offer compelling new genetic evidence from humans supporting the role of alpha globin as a regulator of NO signaling in resistance arteries. We demonstrate that HBA deletions reduce arterial expression of HBA and change arterial vasoreactivity. This clinical investigation defines a novel vascular phenotype for individuals with alpha thalassemia and provides insight into a vascular mechanism by which alpha globin gene deletions protect against severe malaria, chronic kidney disease, and vascular complications of sickle cell disease.

Unstable hemoglobin Montreal II uncovered in an adult with unexplained hemolysis exacerbated by a presumed viral infection: a case report

BackgroundUnstable hemoglobinopathies are rare inherited disorders of hemoglobin causing a reduction of hemoglobin molecule solubility. This results in an unstable hemoglobin tetramer/globin polypeptide, which precipitates within the red blood cell. Affected red blood cells have a reduced lifespan due to oxidative stress and cellular rigidity, and tend to be phagocytized by spleen macrophages more rapidly. Unstable hemoglobin is frequently under- or misdiagnosed, because its clinical presentation varies broadly. Therefore, testing for unstable hemoglobinopathies is indicated in cases of unexplained hemolytic anemia. However, this approach is not systematically followed in clinical practice.Case reportA 25-year-old Caucasian man with a recent history of a presumed viral upper respiratory infection was referred to the hematology outpatient clinic because of hemolytic anemia. The patient had scleral icterus, moderate splenomegaly, and mild macrocytic anemia with high reticulocyte count. Unconjugated bilirubin and lactate dehydrogenase were elevated. Haptoglobin was undetectable. Direct antiglobulin test was negative. Blood smear examination revealed anisopoikilocytosis, polychromasia, bite cells, and basophilic stippling, but no Heinz bodies. High-performance liquid chromatography and capillary electrophoresis showed slightly increased hemoglobin A2, normal fetal hemoglobin, and a variant hemoglobin. Deoxyribonucleic Acid sequencing revealed the heterozygous mutation c430delC in the beta-globin gene hallmark of hemoglobin Montreal II and the heterozygous mutation c287C>T in the alpha-globin gene corresponding to hemoglobin G-Georgia, indicative of the not yet described combination of double-heterozygous hemoglobin Montreal II and hemoglobin G-Georgia variants. Hemoglobinopathy Montreal II was here not associated with β-thalassemia syndrome, and carriers did not show ineffective erythropoiesis. In addition to the case report, we provide information about the largest pedigree with hemoglobinopathy Montreal II identified to date.ConclusionWe emphasize that a transitory acute condition may uncover an underlying inherited red blood cell disorder. In this regard, awareness should be raised among hematologists caring for adult patients that unstable hemoglobinopathies should be considered in the differential diagnosis of unexplained hemolytic anemias.

Genotype\u2013phenotype correlation in patients with deletional and nondeletional mutations of Hb H disease in Southwest of Iran

We studied the alpha-globin gene genotypes, hematologic values, and transfusion-dependence of patients with Hb H disease. Molecular characterization of alpha-thalassemia was performed. We identified 120 patients with Hb H disease. Of these patients, 35 (29.16%) had deletional form of Hb H disease, and 85 (70.83%) had different form of non-deletional Hb H disease. The most frequently observed Hb H genotypes were --Med/–α3.7 in 33 patients (27.5%), αCD19(-G) α/αCD19(-G) α in 25 cases (20.83%), αpolyA2α/αpolyA2α in 15 (12.5%), and αpolyA1α/αpolyA1α in 13 (10.83%) respectively. The probability of receiving at least one transfusion blood in deletional form was observed in 3 of 35 (8.57%) patients which just seen in 3 of 33 (9%) patients with --Med/–α3.7 genotype. This form was also observed in 8 of 85 (9.4%) patients in non-deletional Hb H diseases which five of them had Med deletion in compound with alpha globin point mutations. Nondeletional Hb H disease was more severe than deletional Hb H disease requiring more blood transfusions. We can recommend that Med deletion in compound with alpha-globin point mutations, polyA1 and constant spring in homozygous form needs to be taken into consideration when offering counseling to high-risk couples.

Biochemical Investigation Limits in Recognizing Some Abnormal Hemoglobin Types: Hemoglobins O Arab And S

Hemoglobinopathies are a major health problem worldwide. These disorders are characterized by a variable clinical and hematological situation related to a phenotypic heterogeneity. Moreover, in order to have an exact correlation between the biochemical picture and the genetic defect associated with it, it is useful and often indispensable the molecular study of alpha and beta globin genes. The present case report concerns a pregnant woman of Moroccan ethnicity who came to our observation to undergo combined first-trimester testing useful for screening of major chromosomal aneuploidies. Study of hemoglobins A, A2, and F by High performance liquid chromatography (HPLC) revealed the presence of a proportion of abnormal hemoglobin associated with hemoglobin S. Molecular investigation of globin genes excluded that the biochemical variant in question was related to hemoglobin S. In fact, molecular investigation of beta globin genes, found that the observed variant was due to the presence of a genetic defect leading to hemoglobin O Arab synthesis. Evidence suggests that molecular analysis of globin genes provides the most effective and correct way to correlate the detected biochemical picture with its associated genetic defect. The only biochemical study in the presented case determines an incorrect clinical evaluation with consequent inaccurate prognosis. The mutation detected in this work can be identified using a simple and inexpensive kit. This would generate, in economic terms, significant savings associated with a correct diagnosis

The Effect of Alpha Thalassemia, HbF and HbC on Haematological Parameters of Sickle Cell Disease Patients in Ibadan, Nigeria.

BackgroundSickle cell disease is a protean disease with limited data on Nigeria’s phenotypic and genetic variants. This study was conducted to provide baseline data on these variants by characterising the existing forms of sickle cell disease and correlating these with basic haematological parameters.MethodsAdult and paediatric patients with SCD were recruited from a tertiary health centre in Nigeria. Patients were age and sex-matched with healthy controls. Blood samples were obtained for Full Blood Count, phenotyping by High-Performance Liquid Chromatography, and genotyping for alpha thalassemia by multiplex Gap-polymerase chain reaction. Data analysis was done using IBM SPSS statistics version 23.ResultsA total of 130 patients with sickle cell disease and 117 controls were studied. Alpha thalassemia in the study population was due to a 3.7kb deletion in the alpha-globin gene cluster at a prevalence of 45.4% in the patients and 47% in the controls. The prevalence of the various existing forms of SCD genotype was: Homozygous S without alpha gene deletion (HbSS)- 39.2%; HbSC - 10.8%; HbSSα+1- 35.4%; HbSSα+2 - 6.9% and HbSF- 7.7%. In the control population, HbAA without alpha gene deletion had a prevalence of 42.7%, HbAAα+1 was 25.6%, HbAA α+2 was 6%, HbAS- 7.7%, HbAS α+1 – 11.1%, HbAS α+2 - 2.6%, HbAC – 2.6% and HbAC α+1 – 1.7%. HbA2 was significantly elevated in HbSS individuals with two alpha gene deletions but reduced in normal controls (HbAA) with alpha gene deletions. HbF and HbA2 were negatively correlated with each other (r= −0.587, p < 0.001). Individuals with the HbSC genotype followed by HbSSα+2 had the best haematological parameters.ConclusionsHaematological parameters vary with haemoglobin genotype. The C haemoglobin and homozygous alpha-thalassemia deletion had a better ameliorating effect on SCD haematological parameters than the F haemoglobin in this population. The effect of alpha thalassemia on some haematological parameters in SCD patients are reversed in normal controls.

Alpha Globin Gene Copy Number Is Associated with Prevalent Chronic Kidney Disease and Incident End-Stage Kidney Disease among Black Americans.

α-Globin is expressed in endothelial cells of resistance arteries, where it limits endothelial nitric oxide signaling and enhances α-adrenergic-mediated vasoconstriction. α-Globin gene (HBA) copy number is variable in people of African descent and other populations worldwide. Given the protective effect of nitric oxide in the kidney, we hypothesized that HBA copy number would be associated with kidney disease risk. Community-dwelling Black Americans aged ≥45 years old were enrolled in a national longitudinal cohort from 2003 through 2007. HBA copy number was measured using droplet digital PCR. The prevalence ratio (PR) of CKD and the relative risk (RR) of incident reduced eGFR were calculated using modified Poisson multivariable regression. The hazard ratio (HR) of incident ESKD was calculated using Cox proportional hazards multivariable regression. Among 9908 participants, HBA copy number varied from 2 to 6. In analyses adjusted for demographic, clinical, and genetic risk factors, a one-copy increase in HBA was associated with 14% greater prevalence of CKD (PR, 1.14; 95% CI, 1.07 to 1.21; P<0.0001). While HBA copy number was not associated with incident reduced eGFR (RR, 1.06; 95% CI, 0.94 to 1.19; P=0.38), the hazard of incident ESKD was 32% higher for each additional copy of HBA (HR, 1.32; 95% CI, 1.09 to 1.61; P=0.005). Increasing HBA copy number was associated with a greater prevalence of CKD and incidence of ESKD in a national longitudinal cohort of Black Americans.

Clinical and genetic characteristics of hemoglobin H disease in Iran

Hemoglobin H (Hb H) disease is a subtype of α-thalassemia caused by deletional and/or non-deletional mutations in three alpha-globin genes in which the various genotypes determine the disease severity. This study was aimed to investigate the frequency of alpha gene mutations and genotypes and their correlation with hematological and clinical characteristics in Iran. Among 202 patients diagnosed with Hb H disease through a national study in Iran according to standard methods, we had access to the hematologic and clinical findings and genetic data of 101 patients in whom genetic study was performed. Genomic DNA from peripheral blood was extracted and analyzed for identification of α-globin gene mutations using Multiplex Gap Polymerase Chain Reaction, Reverse Hybridization Assay, and finally Direct DNA Sequencing method. Twenty-one different mutations and thirty genotypes were detected in 101 patients with Hb H disease. In total, 39 patients (38.6%) were deletional and 62 patients (61.4%) were non-deletional type of the disease. The -- MED mutation was highly prevalent in almost half of the patients (56.4%). Among various genotypes, –MED/-a3.7 (29.7%) and -α20 .5/-α5NT (6.9%) were the most prevalent genotypes found in the studied group. Patients with non-deletional type presented with more severe hematological and clinical findings. Hb H percentage and serum ferritin levels were significantly higher in non-deletional patients in comparison to the deletional group (p < 0.05). 12 (11.9%) and 40 (39.6%) out of 101 patients were on regular and occasional transfusions, respectively. 83% of those with regular transfusion belonged to the non-deletional group. Among transfusion-dependent patients, –MED/αCSα and α20 .5/-α5NT were the most common genotypes. In this study, two patients with -α20 .5/αCSα and –MED/α−5NT genotypes experienced thrombotic events. This study indicated that although non-deletional genotypes of Hb H disease were responsible for more clinical severity of the disease, due to the presence of severe phenotypes even in deletional types, no definite correlation was found between genotype and phenotype.

Molecular and Haematological Characteristics of alpha-Thalassemia Deletions in Yogyakarta Special Region, Indonesia.

alpha-Thalassemia is caused primarily by deletions of one to two alpha-globin genes and is characterized by absent or deficient production of alpha-globin protein. The South-East Asia (SEA) deletion, 3.7-kb and 4.2-kb deletions are the most common causes. The present study aimed to observe the molecular characteristics of this common alpha-Thalassemia deletions and analyse its haematological parameter. Blood samples from 173 healthy volunteers from thalassemia carrier screening in Yogyakarta Special Region were used. Haematological parameters were analysed and used to predict the carrier subjects. Genotype of suspected carriers was determined using multiplex gap-polymerase chain reaction and its haematological parameters were compared. The boundary site of each deletion was determined by analysing the DNA sequences. Seventeen (9.8%) of the volunteers were confirmed to have alpha-Thalassemia trait. Of these, four genotypes were identified namely -α3.7/αα (58.8%), -α4.2/αα (5.9%), -α3.7/-α4.2 (5.9%) and - -SEA/αα (29.4%). The 5' and 3' breakpoints of SEA deletion were located at nt165396 and nt184700 of chromosome 16, respectively. The breakpoint regions of 3.7-kb deletion were 176-bp long, whereas for 4.2-kb deletion were 321-bp long. The haematological comparison between normal and those with alpha-Thalassemia trait genotype indicated a significant difference in mean corpuscular volume (MCV) (p< 0.001) and mean corpuscular haemoglobin (MCH) (p< 0.001). As for identifying the number of defective genes, MCH parameter was more reliable (p= 0.003). The resultant molecular and haematological features provide insight and direction for future thalassemia screening program in the region.

Alpha-globin gene triplication and its effect in beta-thalassemia carrier, sickle cell trait, and healthy individual.

The genotype and phenotype correlation between coinheritance of heterozygous beta‐thalassemia with the alpha‐globin triplication is unclear. In this study we have investigated and reviewed alpha triplication frequency in beta‐thalassemia carriers, sickle cell trait, and healthy individuals and its effect on hematological and phenotypical changes. In this study, 4005 beta‐thalassemia carriers, 455 sickle cell trait, and 2000 healthy individuals were included. Molecular characterization of beta and alpha‐thalassemia was performed. The frequencies of alpha‐globin triplication in beta‐thalassemia carriers, sickle cell trait, and healthy individuals were 67 (1.67%), 4 (0.88%), and 18 (0.9%), respectively. In total, the frequency of alpha‐triplications is approximately 89 (1.39%) in Khuzestan province, South of Iran population. We have compared the average hematological parameters of beta‐thalassemia carriers, sickle cell trait, and healthy individuals with and without alpha gene triplication.This mutation did not show any significant effect on the change of blood indices, neither in healthy individuals nor in sickle cell trait and beta‐thalassemia carriers. Therefore, there is no need to take more notice of anti 3.7 mutation in beta‐thalassemia carriers is opposed with some studies reported that the presence of excess alpha‐globin genes in beta‐thalassemia carriers can lead to the phenotype of beta‐thalassemia intermedia. Therefore, not every individual with triplicated alpha globin coinherited with beta‐thalassemia trait will have a significantly lower Hb than normal, and it is highly likely that none of them will need transfusion.

RETROSPECTIVE ANALYSIS OF ALPHA GLOBIN COPY NUMBER VARIATIONS DETERMINED BY MLPA IN THE TRAKYA REGION

Objective: Alpha thalassemia is a common type of hemoglobinopathy that occurs as a result of deletions or point mutations in the alpha globin gene cluster. The molecular analysis of alpha thalassemia is challenging due to the presence of genes with high sequence similarities in alpha globin gene clusters and pseudogenes. As well as in all genetic diseases, determining the causative mutation types of alpha thalassemia and their frequencies have critical importance for accurate genetic screening and prevention strategies. Material and Method: In our study, alpha globin copy number variations determined by the Multiplex Ligation-dependent Probe Amplifcation (MLPA) method were examined retrospectively with suspicion of alpha thalassemia in 35 female and 43 male patients tested in the Genetic Diseases Diagnosis Center of the Medical Genetics Department at Trakya University Faculty of Medicine. Results: The most common deletion among our patients was the −α3.7 (35.3%), followed by the -α20.5 (10.3%) deletion. The -αSEA deletion was detected in three patients while 4 out of 78 cases were found to have the -αMED deletion. In three patients, a heterozygous large deletion and in one case HS40 regulatory region deletion were detected. In 14 (18%) of the patients, α globin triplications were detected. The -α4.2 deletion was detected in only one of our patients. Conclusion: Our study is the first to report the presence of eight different alpha globin copy number changes and 13 different alpha globin genotypes in the Trakya region.

Status of anemia among the tribal children in West Bengal

Background: Anemia is a major public health problem worldwide. School children are more vulnerable to this disease due to their rapid growth need of high iron. Therefore, it is a critical health concern because it affects growth and physical performance. This study was undertaken to investigate the prevalence of anemia among different areas and sub-caste of tribal school children in West Bengal.Methods: Complete hemogram was performed on Sysmex (KX-21) automated cell counter. Haemoglobin analysis was done by high performance liquid chromatography (HPLC, from Bio Rad Variant II). Ferritin estimation was done by ELISA based method. A software (Thaltribe) was prepared to record and maintain the data of the screened population.Results: Total number of school students from all the districts of West Bengal included in this study was 45887. Among the total population 49.88% were found to carry low Hb and 28.45% had low ferritin. Among the population who had normal ferritin (N=32832), there were 46.59% (N=15298) carrying low Hb. Among total 15298 cases who had low Hb with normal ferritin level, 10741 (70.21%) remained undiagnosed who were not detected to be thalassaemia carrier or thalassaemia disease (HPLC normal) and also did not carry alpha globin gene mutation.Conclusions: On the contrary to the common belief that iron is the main source of anemia, it was observed in this study that around 25% of anemic children did not have iron deficiency. This group requires further evaluation to investigate the reason of anemia.

Nghiên cứu thực trạng mang gen Thalassemia ở trẻ em người dân tộc Tày, Dao tỉnh Tuyên Quang

Objectives: To determine the prevalence of thalassemia carrier, genotype and hematological parameters among children bearing the thalassemia gene in Tuyen Quang. Methodology: A descriptive study was conducted from January to March 2017. 505 ethnic minority children in 6 districts and Tuyen Quang City, Tuyen Quang province were registered voluntarily by the family in the study. MCV index &lt;80fL combined with the DCIP test were used for screening thalassemia and HbE. Hemoglobin electrophoresis and DNA analysis of mutations in the globin alpha gene was performed for all cases positive with screening tests. Results: The prevalence of thalassemia common for ethnic minority children in Tuyen Quang was 28,1%. Four types of single-gene mutations in the alpha globin gene were identified, following types --SEA, -α3.7; -αCS; -α4.2. Conclusion: The general prevalence of thalassemia gene among the Tay and Dao children in Tuyen Quang is 28.1%. Six phenotypic groups carrying thalassemia gene were detected with 10 mutant genotypes. Mutation - SEA accounts for the highest proportion of single allele mutations (72.09%). Keywords: Thalassemia carrier, children, ethnic Tay, ethnic Dao, Tuyen Quang

A Rare Case of Hemoglobin Bart’s Hydrops Fetalis due to Uniparental Disomy of Chromosome 16

Hemoglobin (Hb) Bart’s hydrops fetalis is the most severe form of alpha-thalassemia and is usually inherited in an autosomal recessive manner. We report a case of Hb Bart’s hydrops fetalis due to uniparental disomy of chromosome 16. Antenatal screening showed a low maternal mean corpuscular volume (MCV), while paternal MCV was normal. The fetus was found to have a thickened nuchal translucency during first trimester screening for Down’s syndrome. Mid-trimester fetal anomaly ultrasound scan showed fetal cardiomegaly with pericardial effusion, scalp edema, ascites and an elevated middle cerebral arterial peak systolic velocity (MCA PSV). Multiplex polymerase chain reaction (PCR) on DNA from amniocentesis showed that the fetus was homozygous for South East Asian (SEA) type 2 alpha-globin gene deletion. Chromosome microarray (CMA) showed two regions of absence of heterozygosity (AOH) on the terminal p and q arm of chromosome 16. The rare occurrence of Hb Bart’s hydrops fetalis caused by maternal uniparental disomy should be considered in cases of fetal hydrops even in cases where paternal MCV is normal. J Med Cases. 2021;12(7):275-279 doi: https://doi.org/10.14740/jmc3693

The Multiple Facets of ATRX Protein.

Simple SummaryThe gene encoding for the epigenetic regulator ATRX is gaining a prominent position among the most important oncosuppressive genes of the human genome. ATRX gene somatic mutations are found across a number of diverse cancer types, suggesting its relevance in tumor induction and progression. In the present review, the multiple activities of ATRX protein are described in the light of the most recent literature available highlighting its multifaceted role in the caretaking of the human genome.ATRX gene codifies for a protein member of the SWI-SNF family and was cloned for the first time over 25 years ago as the gene responsible for a rare developmental disorder characterized by α-thalassemia and intellectual disability called Alpha Thalassemia/mental Retardation syndrome X-linked (ATRX) syndrome. Since its discovery as a helicase involved in alpha-globin gene transcriptional regulation, our understanding of the multiple roles played by the ATRX protein increased continuously, leading to the recognition of this multifaceted protein as a central “caretaker” of the human genome involved in cancer suppression. In this review, we report recent advances in the comprehension of the ATRX manifold functions that encompass heterochromatin epigenetic regulation and maintenance, telomere function, replicative stress response, genome stability, and the suppression of endogenous transposable elements and exogenous viral genomes.

Usefulness of NGS for Diagnosis of Dominant Beta-Thalassemia and Unstable Hemoglobinopathies in Five Clinical Cases.

Unstable hemoglobinopathies (UHs) are rare anemia disorders (RADs) characterized by abnormal hemoglobin (Hb) variants with decreased stability. UHs are therefore easily precipitating, causing hemolysis and, in some cases, leading to dominant beta-thalassemia (dBTHAL). The clinical picture of UHs is highly heterogeneous, inheritance pattern is dominant, instead of recessive as in more prevalent major Hb syndromes, and may occur de novo. Most cases of UHs are not detected by conventional testing, therefore diagnosis requires a high index of suspicion of the treating physician. Here, we highlight the importance of next generation sequencing (NGS) methodologies for the diagnosis of patients with dBTHAL and other less severe UH variants. We present five unrelated clinical cases referred with chronic hemolytic anemia, three of them with severe blood transfusion dependent anemia. Targeted NGS analysis was performed in three cases while whole exome sequencing (WES) analysis was performed in two cases. Five different UH variants were identified correlating with patients’ clinical manifestations. Four variants were related to the beta-globin gene (Hb Bristol—Alesha, Hb Debrousse, Hb Zunyi, and the novel Hb Mokum) meanwhile one case was caused by a mutation in the alpha-globin gene leading to Hb Evans. Inclusion of alpha and beta-globin genes in routine NGS approaches for RADs has to be considered to improve diagnosis’ efficiency of RAD due to UHs. Reducing misdiagnoses and underdiagnoses of UH variants, especially of the severe forms leading to dBTHAL would also facilitate the early start of intensive or curative treatments for these patients.

Common Alpha Globin Genes (HBA1 and HBA2) Mutations in Filipino Patients with Alpha Thalassemia

Alpha (α) thalassemia results from the absence/reduced synthesis of the α-globin subunit of hemoglobin (Hb). Mutational variants in the HBA1 and HBA2, which code for α-globin, have been reported to cause varying degrees of disease severity. These variants are unique for every population. However, local data on α-globin gene mutations in Filipino α-thalassemics is currently lacking. This study aimed to identify common α-globin gene mutations in Filipino patients suspected with α-thalassemia. Two hundred sixty (260) patients suspected with α-thalassemia underwent deoxyribonucleic acid (DNA) extraction and Alpha Globin StripAssay® mutational analysis. The (--SEA/αα), (-α3.7/--SEA), (-α3.7/--FIL), (--FIL/αα), (αα/αα), (-α3.7/αα), (-α3.7/-α3.7), (-α4.2/--SEA), (--SEA/--SEA), (α2 cd 59/αα), (-α4.2/-α4.2), (-α4.2/--FIL), (--SEA/ ααCS), and (-α3.7/-α4.2) mutations were found in 30.38%, 24.62%, 20.77%, 12.31%, 6.15%, 1.54%, 1.15%, 0.77%, 0.38%, 0.38%, 0.38%, 0.38%, 0.38%, and 0.38% of the patients, respectively. These results indicate that the (--SEA/αα), (-α3.7/--SEA) and (-α3.7/--FIL) mutations are prevalent in the Filipino patients tested. The high frequencies of (--SEA, 28.46%), (-α3.7, 24.81%) and (-- FIL, 16.73%) alleles in this study are important to note as these alleles may increase the risk of HbH and Hb Bart’s hydrops fetalis cases in the population.

Investigation of Alpha Globin Gene Mutations by Complementary Methods in Antalya

Investigation of Alpha Globin Gene Mutations by Complementary Methods in Antalya