Hemoglobinopathies in the United Arab Emirates

Healthcare resource utilization and direct costs of transfusion-dependent thalassemia patients in Dubai, United Arab Emirates: a retrospective cost-of-illness study

Background

Patients with transfusion-dependent thalassemia (TDT) require lifelong blood transfusions and iron chelation therapy. Thus, patients afflicted with TDT often have to undergo blood transfusion and iron chelation therapy, which causes a major economic burden on them. However, this topic has not been reported in Dubai, United Arab Emirates (UAE). Hence, this study aimed to evaluate healthcare resource utilization and associated direct costs related to patients with TDT in Dubai, UAE.

Methods

For this study, a retrospective prevalence-based cost-of-illness analysis based on the UAE healthcare system and patient perspectives was conducted among patients with TDT treated at the Dubai Thalassemia Center in 2019. Information regarding healthcare resource utilization and direct medical costs was collected from the billing system connected to the electronic medical record system. Patients and their families were interviewed for direct non-medical cost estimations.

Results

A total of 255 patients with TDT were included in the study. The mean annual direct medical cost was estimated at AED 131,156 (USD 35,713) (95% CI: 124,735 – 137,578). The main driver of the medical cost for the participants as iron chelation therapy AED 78,372 (95% CI: 72,671 – 84,074) (59.8%), followed by blood transfusions, which accounted for AED 34,223 (95% CI: 32,854 – 35,593) 26.1% of the total direct medical costs. The mean annual direct non-medical costs was AED 2,223 (USD 605) (95% CI: 1,946 – 2,500). Age (p < 0.001), severe serum ferritin levels (p = 0.016), the presence of complications (p < 0.001), and the type of iron chelation therapy (p < 0.001) were significant predictors of higher direct medical costs incurred by the participants.

Conclusion

Transfusion-dependent thalassemia poses a substantial economic burden on the healthcare system, patients, and their families. Our results show that the highest medical cost proportion was due to iron chelation therapy. In this regard, efforts must be made to improve the patients’ acceptance and satisfaction with their iron chelation therapy to increase their compliance and improve the effectiveness of treatment, which could play an essential role in controlling the economic burden of this disease. Moreover, greater support is essential for families that suffer catastrophic out-of-pocket expenses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-07663-6.

α-Globin Genotypes Associated with Hb H Disease: A Report from Oman and a Review of the Literature from the Eastern Mediterranean Region

α-Thalassemia (α-thal) is the most common autosomal recessive hemoglobinopathy. There is a vast diversity and geographical variability in underlying genotypes in Hb H (β4) patients. Herein, we describe the genotypes found in the largest report of Omani Hb H patients. Moreover, we reviewed and summarized the literature published from the Eastern Mediterranean region. A retrospective review of all genetically confirmed Hb H disease patients diagnosed between 2007 and 2017 at Sultan Qaboos University Hospital, Muscat, Oman, was performed. Hematological parameters and clinical presentations were assessed. Both α-globin genes were screened for deletional and nondeletional mutations using a stepwise diagnostic strategy as described before. A total of 52 patients (27 females and 25 males) with a mean age of 20.6 years (range 0.23-80.0) were molecularly confirmed to carry Hb H disease. The patients had a hemoglobin (Hb) level of 9.3 g/dL (range 5.7-13.0) and mean corpuscular volume (MCV) of 58.4 fL (range 48.2-82.1). A total of eight genotype combinations were identified, with α2 polyadenylation signal mutation (polyA1) (AATAAA>AATAAG (α^PA1α/α^PA1α), often cited as α^T-Saudiα/α^T-Saudiα, being the most common (53.8%) followed by -α^3.7/- -^{MED I} (28.8%). Our cohort also included patients with combinations of α^PA1 with other Hb variants: α^PA1α/α^PA1α with Hb S (HBB: c.20A>T) trait (n = 2), -α^3.7/α^PA1α (n = 2) and α^{codon 19}α (HBA2: c.56delG)/α^PA1α (n = 1). Nondeletional Hb H disease due to the α^PA1 mutation is the most common in Omanis. Molecular diagnosis is necessary for accurate confirmation of the diagnosis of α-thal, determination of underlying genotypes, follow-up and counseling.

Misdiagnosis of Hb D-Punjab/β-thalassemia is a potential pitfall in hemoglobinopathy screening programs: a case report

Compound heterozygosity for Hb D-Punjab [β121(GH4)Glu→Gln, GAA>CAA] /β-thalassemia (β-thal) must be carefully differentiated from homozygous Hb D-Punjab in premarital screening. This is essential when the partner is a carrier of β-thal trait. The case of a baby born affected with β-thal major (β-TM), from a marriage between a mother with β-thal trait and a father with Hb D-Punjab/β-thal, is presented. The father had been misdiagnozed as homozygous Hb D-Punjab during premarital screening, even though the screening program utilized complete blood counts and high performance liquid chromatography (HPLC). The factors that may have contributed to this midsiagnosis are presented and discussed. It is recommended that cases of Hb D-Punjab, or any other hemoglobin (Hb) variant appearing as homozygous, are carefully evaluated if microcytic hypochromic parameters not associated with α-thal are present. In all cases of suspected hemizygosis, molecular analysis should always be performed, and in particular if one partner is a β-thal carrier.

Beta-Thalassemia in Iran: new insight into the role of genetic admixture and migration

Iran with an area of 1.648 million km² is located between the Caspian Sea and the Persian Gulf. The Iranian population consists of multiethnic groups that have been influenced by various invasions and migration throughout history. Studies have revealed the presence of more than 47 different β-globin gene mutations responsible for β-Thalassemia in Iran. This paper is an attempt to study the origin of β-Thalassemia mutations in different parts of Iran. Distribution of β-Thalassemia mutations in Iran shows different patterns in different areas. β-Thalassemia mutations have been a reflection of people and area in correlation with migration and origin of ancestors. We compared the frequencies of β-globin mutations in different regions of Iran with those derived from neighboring countries. The analysis provided evidence of complementary information about the genetic admixture and migration of some mutations, as well as the remarkable genetic classification of the Iranian people and ethnic groups.

Epidemiological profile of common haemoglobinopathies in Arab countries

Haemoglobinopathies including the thalassemias and sickle cell disease are known to be prevalent inherited disorders in most Arab countries with varying prevalence rates and molecular characterisation. β-thalassemia is encountered in polymorphic frequencies in almost all Arab countries with carrier rates of 1-11 % and a varying number of mutations. The most widespread mutation in Lebanon, Egypt, Syria, Jordan, Tunisia and Algeria is the IVS-I-110 (G>A). In the Eastern Arabian Peninsula, the Asian Indian mutations (IVS-I-5 (G>C), codons 8/9 (+G) and IVS-I (-25 bp del)) are more common. The α-thalassemias are encountered in the majority of Arab countries in frequencies ranging from 1 to 58 % with the highest frequencies reported from Gulf countries. The (-α(3.7)) mutation is the most frequent followed by the non-deletional α2 polyadenylation signal mutation (AATAAA>AATAAG) and the α2 IVS1 5-bp deletion. The rates of sickle cell trait in Arab countries range from 0.3 to 30 %, with the Benin, the Arab-Indian and the Bantu haplotypes constituting the bulk of the haplotypes, leading to two major phenotypes; a mild one associated with the Arab-Indian and a severe one with the Benin and Bantu haplotypes. Public health approaches targeting prevention of haemoglobinopathies in Arab countries include newborn screening for sickle cell disease, and premarital screening for carriers of β-thalassemia and sickle cell disease. These services are still patchy and inadequate in many Arab countries recommending the upgrade of these services with strengthening of the education and training of health care providers and raising public awareness on the feasibility of prevention and care for haemoglobinopathies.

Sickle cell disease in Middle East Arab countries

The sickle cell (HbS) gene occurs at a variable frequency in the Middle Eastern Arab countries, with characteristic distribution patterns and representing an overall picture of blood genetic disorders in the region. The origin of the gene has been debated, but studies using β-globin gene haplotypes have ascertained that there were multiple origins for HbS. In some regions the HbS gene is common and exhibits polymorphism, while the reverse is true in others. A common causative factor for the high prevalence and maintenance of HbS and thalassaemia genes is malaria endemicity. The HbS gene also co-exists with other haemoglobin variants and thalassaemia genes and the resulting clinical state is referred to as sickle cell disease (SCD). In the Middle Eastern Arab countries, the clinical picture of SCD expresses two distinct forms, the benign and the severe forms, which are related to two distinct β-globin gene haplotypes. These are referred to as the Saudi-Indian and the Benin haplotypes, respectively. In a majority of the Middle Eastern Arab countries the HbS is linked to the Saudi-Indian haplotype, while in others it is linked to the Benin haplotype. This review outlines the frequency, distribution, clinical feature, management and prevention as well as gene interactions of the HbS genes with other haemoglobin disorders in the Middle Eastern Arab countries.

Molecular basis of β-thalassemia in the United Arab Emirates

In an attempt to define the prevalence of β-thalassemia (β-thal) in the United Arab Emirates (UAE), we have conducted molecular studies on nearly 2000 randomly-selected adult UAE nationals. The results demonstrated that the prevalence of β-globin gene defects in the UAE was 8.5%. Among these anomalies were β-thal mutations, abnormal hemoglobin (Hb) variants, e.g., Hb S, Hb D-Punjab, Hb O-Arab, Hb C and Hb E. The sickle gene (β(S) or Hb S) contributed significantly to the molecular epidemiology of the hemoglobinopathies in the UAE. In this article, Hb S and other abnormal Hbs are excluded as they are comprehensively described by other contributors in this current issue. The molecular characterization and mutational analyses of all β-thal patients were carried out using current molecular techniques including amplification refractory mutation system (ARMS), restriction enzyme analysis (REA), dot-blot hybridization, β-strip hybridization, allele-specific oligonucleotide (ASO), polymerase chain reaction (PCR), gap-PCR and DNA Sequencing. Most of these techniques are now virtually obsolete. Almost all molecular characterizations are currently performed through PCR followed by DNA sequencing using a fully automated ABI PRISM™ 3130 Genetic Analyzer. Our molecular studies showed that the majority of the β-thal mutations in the UAE are very severe; the most common allele was the IVS-I-5 (G>C). Although this allele is a β(+)-thal, its phenotype is very severe. All other mutations are also severe β(0)-thal. High frequency of moderate or severe β-thal mutations have implications in the wide spectrum of clinical manifestations seen in patients whose phenotypes vary from β-thal intermedia (β-TI) to severe transfusion-dependent β-thal major (β-TM). The molecular pathology of the β-thal patients demonstrated that a vast majority were homozygous. The most frequent homozygous mutation was the IVS-I-5(G>C)/IVS-I-5(G>C) (53.0%) followed by -25 bp del/-25 bp del (6.8%), codons 8/9(+G)/codons 8/9(+G) (2.8%) and codon 39(C>T)/codon 39(C>T) (2.4%). Four mutations accounted for 65.0% of the homozygous patient population. Remarkably, the two most prevalent mutations, IVS-I-5 and Hb S, accounted for 77% of all the homozygous β-thal patients from the UAE. We showed 13 discrete homozygosities in the UAE national patients in contrast to 23 homozygosities in the expatriate population. Since the number of homozygous mutations has a direct correlation with the degree of consanguinity, the data shown here corroborate the social tendency towards family planning. In fact, in the UAE, more than 50% of all marriages are between relatives and more than half of these are between first cousins.

The Diagnosis of α-Thalassaemia: A Case of Hemoglobin H -α Deletion

We report a case of hemolytic anemia that was subsequently identified to be a case of α-thalassaemia harboring the common rightward 3.7 kb deletion/HbH. The diagnosis was based on sequential analyses using BioRad D10 HPLC, Alkaline gel electrophoresis, GPO α THAL-IC strips and the identification of the specific genetic lesion using an α Globin reverse dot blot hybridization assay. Supravital stain of RBCs helped in identifying classical HbH inclusions. In a background of a variable clinical presentation, lack of definitive hematological markers, and general under-diagnosis of α-thalassaemias we have used this case to highlight the features and sequence of techniques involved in identifying and characterizing an α-globin chain mutation, starting from a diffuse clinical history and presentation up to the identification of a specific genetic lesion involved.

Mutations of a country: a mutation review of single gene disorders in the United Arab Emirates (UAE)

The United Arab Emirates inhabitants are ethnically diverse, with ancestries from Arabia, Persia, Baluchistan, and Africa. However, the majority of the current five million inhabitants are expatriates from the Asian subcontinent, Middle Eastern, African, and European countries. Consanguineous marriages within most UAE subpopulations are still the norm, leading to the formation of isolates and higher frequencies of recessive conditions. The UAE is ranked sixth in terms of prevalence of birth defects, with more than 270 genetic disorders reported in the national population. The UAE has high frequencies of blood disorders including thalassemias, sickle cell disease, and G6PD. In addition, certain genetic conditions are relatively common including cystic fibrosis, Joubert, and Meckel syndromes. Furthermore, numerous rare congenital malformations and metabolic disorders have been reported. We review the single gene disorders that have been studied at the molecular level in the UAE (which currently stand at 76) and compile the mutations found. Several novel (p.S2439fs) mutations have been reported including c.7317delA in NF1, c.5C>T (p.A2V) in DKC1, c.1766T>A (p.I589N) in TP63, and c.2117G>T (p.R706L) in VLDLR. We hope that this review will form the basis to establish a UAE mutations database and serve as a model for the collection of mutations of a country.

Molecular Basis of β‐Thalassemia in the Population of Tunisia

The present study attempts to delineate the spectrum of beta-thalassemia (thal) mutations in Tunisia by studying a large population from different parts of the country. A total of 285 unrelated subjects, 190 of whom had beta-thal major, 72 with Hb S/beta-thal, one with Hb C/beta-thal, one with Hb O-Arab/beta-thal and 21 beta-thal carriers, were studied. The molecular defects were detected in 97.7% of the beta-thalassemic chromosomes (n=475). Nineteen different beta-thalassemic alleles were identified. Two mutations, namely codon 39 (C-->T) and IVS-I-110 (G-->A) accounted for 70.0% of the studied chromosomes, followed by IVS-I-1 (G-->A) (4.5%). Five other mutations, frameshift codon (FSC) 44 (-C), codon 30 (G-->C), IVS-I-2 (T-->G), IVS-II-745 (C-->G), and FSC 6 (-A), are not uncommon in this population, while the remaining 11 mutations, IVS-I-5 (G-->A), -30 (T-->A), codons 25/26 (+T), IVS-I-6 (T-->C), FSC 5 (-CT), IVS-II-848 (C-->A), FSC 8 (-AA), -87 (C-->G), IVS-I-5 (G-->C), IVS-II-1 (G-->A) and IVS-II-849 (A-->C) are quite rare; four of these have not been previously reported in the Tunisian population. Potential origin and spread of these mutations to Tunisia are also discussed.

Consanguineous marriages and endemic malaria: can inbreeding increase population fitness?

Background

The practice of consanguineous marriages is widespread in countries with endemic malaria. In these regions, consanguinity increases the prevalence of α⁺-thalassemia, which is protective against malaria. However, it also causes an excessive mortality amongst the offspring due to an increase in homozygosis of recessive lethal alleles. The aim of this study was to explore the overall effects of inbreeding on the fitness of a population infested with malaria.

Methods

In a stochastic computer model of population growth, the sizes of inbred and outbred populations were compared. The model has been previously validated producing results for inbred populations that have agreed with analytical predictions. Survival likelihoods for different α⁺-thalassemia genotypes were obtained from the odds of severe forms of disease from a field study. Survivals were further estimated for different values of mortality from malaria.

Results

Inbreeding increases the frequency of α⁺-thalassemia allele and the loss of life due to homozygosis of recessive lethal alleles; both are proportional to the coefficient of inbreeding and the frequency of alleles in population. Inbreeding-mediated decrease in mortality from malaria (produced via enhanced α⁺-thalassemia frequency) mitigates inbreeding-related increases in fatality (produced via increased homozygosity of recessive lethals). When the death rate due to malaria is high, the net effect of inbreeding is a reduction in the overall mortality of the population.

Conclusion

Consanguineous marriages may increase the overall fitness of populations with endemic malaria.

Physical fitness indices and anthropometrics profiles in schoolchildren with sickle cell trait/disease

The current studies aimed at determining physical fitness indices and anthropometrics profiles of school children with sickle cell trait (SCT) and sickle cell disease (SCD). Male school children (150) comprising 3 Groups participated in the studies. Group 1 has 50 normal healthy controls, while Groups 2 and 3 each has 50 children who were suffering from SCT and SCD, respectively. Anthropometrics measurement and parameters of physical fitness were assessed in all subjects. All children were also subjected to a 5-min running exercise test on a flat motorized treadmill at speed corresponding to 5 km/hr. Throughout the test, heart rate was monitored and recorded during exercise and for 10-min during recovery. Blood lactate was measured before and 5 min following the completion of test. The mean values of lean body mass and height were lower in the SCD children (P < 0.05) compared with the healthy subjects and SCT individuals. Children with SCD exhibited a higher mean value (P < 0.05) for percent body fat and fat mass than the normal healthy subjects and SCT individuals. Although all groups tolerated well the treadmill exercise protocol, the SCD group exhibited higher (P < 0.05) mean values of heart rate during exercise than those observed in the SCT and normal control children. In addition, SCD children showed higher serum lactate values before and after treadmill exercise compared to the other groups. Children with SCD exhibit high level of adiposity; low level of fitness and their exercise performance appears to be physiologically more stressful as indicated by heart rate and blood lactate concentration responses.

United Arab Emirates: communities and community genetics

The UAE society is cosmopolitan, but the indigenous inhabitants are traditional with puritanical values despite their exposure to other vastly different cultures and habits. Marriages between consanguineous couples are still the norm rather than the exception. As a result, there is a high frequency of genetic disorders, particularly autosomal recessive types. Despite the high frequency of genetic disorders like haemoglobinopathies and others characteristically found in this population, genetic services are inadequate. Screening for certain disorders like thalassaemia are not applied on a wide scale. Abortion is illegal, and therefore, prenatal diagnosis or preconception tests are not done. With the absence of a good national database, deficiency of genetic services and absence of preventative alternatives for carrier couples, genetic counsellors find it difficult to advice pragmatic solutions to issues relating to genetic diseases. This paper reviews common genetic problems in the UAE with special emphasis on available genetic services and support to families with children with inherited disorders. Existing barriers to the improvement of clinical services by prenatal counselling are also discussed.

Enfermedad de células falciformes: registro de la Sociedad Española de Hematología Pediátrica

INTRODUCTION

Sickle cell disease (SCD), a genetic anemia, is currently an emerging health problem in Spain. Since 2000, The Spanish Society of Pediatric Hematology has maintained a registry of these patients. The data corresponding to 2004 are presented herein.

PATIENTS AND METHODS

Information was sent by different national hospitals. Pediatric patients with SCD followed-up during 2003 were registered in the first quarter of 2004. Data on epidemiology, diagnosis, treatment and outcome in each patient were gathered.

RESULTS

A total of 138 patients in 24 national hospitals were registered. Of these, 99 were still under follow-up. There was no significant difference in sex. The mean age was 8.2 years. Seventy-eight percent of the patients were homozygous. Forty-four percent were born in Africa but 76% had abnormal genes originating in Africa. Neurophysiologic disorders were detected in 36% of the patients. Symptomatic treatment was given in 65%, hydroxyurea in 27%, hypertransfusional therapy in 3%, and chelation therapy, indicated for ferric overload, was provided in 4%. None of the patients underwent stem cell transplantation. Acute complications requiring hospitalization occurred in 21%, and chronic complications were observed in 27%. The most frequent chronic complications were delayed height and weight gain and liver and biliary tract disorders. Two patients died.

CONCLUSIONS

This study confirms a highly significant increase in the prevalence of pediatric patients with SCD in the last 4 years, requiring greater resources to be devoted to the diagnosis and follow-up of this disease.

β-Thalassemia major and its effect on amino acid metabolism and growth in patients in the United Arab Emirates

BACKGROUND

There may be a marked reduction in essential amino acids in the serum of children with thalassemia major and this is related to decreased growth in affected children.

METHODS

One hundred patients with beta-thalassemia and 50 control children selected from among those who had presented with minor disorders unrelated to hematological disease were recruited. Urine and heparinized blood were collected from fasting thalassemic patients. After deproteinization and dilution, amino acid concentrations were measured using ion-exchange chromatography.

RESULTS

Isoleucine (p<0.0001), phenylalanine (p<0.05), tyrosine (p<0.0001), taurine (p<0.0001) and glutamine (p<0.01) were significantly decreased in the plasma of thalassemic patients compared to the control group. Whereas glutamate (p<0.0001), serine (p<0.05) and proline (p<0.05) were significantly higher in thalassemic patients, threonine, glycine, alanine, valine, methionine, leucine, ornithine, lysine, histidine and arginine values were not different. The essential amino acids taurine (p<0.0001), methionine (p<0.01), valine (p<0.01), phenylalanine (p<0.01) and leucine (p<0.05) were significantly decreased in urine of thalassemic patients vs. controls, but threonine and ornithine were not different. The mean urinary excretion rate of beta-aminoisobutyric acid was not different (69+/-96 in thalassemics vs. 41+/-52 in controls). However, most plasma and urinary essential amino acids were found to be lower in thalassemics. Thalassemic patients were also found to be significantly growth impaired for age, both in height and weight compared to controls.

CONCLUSION

Lower plasma values of essential amino acids and a decrease in urinary amino acids occur in thalassemic patients. Growth impairment both in height and weight also occurs in thalassemic patients compared to a control population.

Molecular Heterogeneity of Beta-Thalassemia in the United Arab Emirates

The beta-thalassemia alleles in 313 national patients of the United Arab Emirates (UAE) have been characterized using PCR-based DNA-diagnostic techniques including DNA sequencing. A total of 212 patients had homozygous beta-thalassemia and the remaining 101 were compound heterozygotes. More than half of the patients were homozygous for the IVS-I-5 (G-->C) mutation followed by the sickle cell gene. The latter accounted for 25% of the chromosomes. In terms of frequency, five beta-thalassemia mutations; IVS-I-5 (G-->C), betaS, -25 bp del, Cd 8/9 (+G) and IVS-II-1 (G-->A) accounted for 83% of the alleles. In addition, 427 expatriate patients were studied: 256 with homozygous beta-thalassemia and 171 were compound heterozygotes. In both the UAE nationals and expatriates, the beta-thalassemia mutations and their frequency followed a similar trend. Our results indicate that the frequency of beta-globin gene defects including beta-thalassemia, sickle cell gene (betaS) and abnormal hemoglobins is significantly increased and poses a major public health problem in the UAE. The number of homozygous patients strongly suggests a high degree of consanguinity among the UAE nationals. With 50 different beta-thalassemia alleles, UAE is arguably the most heterogeneous population in the world. The diversity of these mutations reflects the historical admixture of genes and their migration from different areas in the region. Our data strongly suggest the need for a comprehensive thalassemia control program and provides a basis for population screening, genetic counseling and prenatal diagnosis.