Haplotype analysis of beta thalassemia patients in Western Iran

Updated Molecular Spectrum of β-Thalassemia Mutations in Duhok Province, Northern Iraq: Ethnic Variation and the Impact of Immigration

Immigration impact on genetic epidemiology of thalassemia worldwide is well-recognized. Over the past decade, the Duhok Province of Northern Iraq attracted a large number of immigrants. To assess whether immigration had contributed to changes in the mutation spectrum of β-thalassemia (β-thal) in the region, we recruited 218 registered patients with symptomatic β-thal. The recruited patients included 50 (22.9%) from resettled migrant families. A total of 431 β-thal alleles were fully characterized, with 20 different thalassemia mutations, the most frequent being IVS-II-1 (G>A) (HBB: c.315 + 1G>A), IVS-I-6 (T>C) (HBB: c.92 + 6T>C), codon 5 (-CT) (HBB: c.17_18delCT), IVS-I-110 (G>A) (HBB: c.93-21G>A), codon 44 (-C) (HBB: c.135delC), codon 8 (-AA) (HBB: c.25_26delAA) and IVS-I-1 (G>A) (HBB: c.92 + 1G>A) constituting 72.8% of the total. Some differences in mutation spectrum were observed compared to earlier studies from this same province, the most notable of which were the higher frequencies of IVS-I-110 and codon 8. Interestingly, the highest proportions of alleles related to immigrants were encountered in these two allele groups. Ethnic variation was also documented, so that while Muslim Kurds had IVS-II-1, IVS-I-6, IVS-I-110, codon 5 and codon 44 as their most frequent mutations, the most frequent among Kurdish Yazidis, were codon 5, codon 44, codon 8 and IVS-I-6. These ethnic variations and changes in mutation spectrums are important and should be taken in consideration to ensure effective implementation of the thalassemia preventive program.

The worldwide molecular spectrum and distribution of thalassaemia: a systematic review

CONTEXT

Thalassaemia is one of the most common inherited autosomal recessive disorders around the world. A considerable amount of literature has been published about the type of mutations and the prevalence of thalassaemia, but findings are often contradictory.

OBJECTIVE

This systematic review aimed to provide a comprehensive view of the prevalence of thalassaemia-associated mutations in different countries, their effect on haemoglobin (Hb) levels, as well as reporting thalassaemia-associated rare mutations.

METHODS

A systematic search of the literature was carried out through major indexing databases (MEDLINE/PubMed, Scopus, EMBASE, Cochrane central, and ISI web of science) using keywords: "Co-inheritance, αα, β, thalassaemia" and "α-β thalassaemia, Mediterranean anemia, mutations" from 1998-September 2019. Hand-searching was also performed. There was no language restriction.

RESULTS

The initial searches yielded 1059 studies, of which 92 articles were included following inclusion and exclusion criteria. Of these, 3.3% (3) of articles were cohort studies, and 96.7% (89) of the remaining articles were cross-sectional studies. Our findings showed that 45.6% (42) of researchers investigated β-thalassaemia, 22.9% (21) αα-β thalassaemia, and 31.5% (29) α thalassaemia.

CONCLUSION

The present study provides valuable information about the spectrum of thalassaemia-associated mutations, which can be useful for preventing thalassaemia, reducing costs of care, reducing the treatment-related side effects, and showing the most defective mutations.HighlightEvaluating the increase or decrease in the birth prevalence of thalassaemiaIdentifying the most common and rare mutations in various parts of the worldComparing researchers' findings from various parts of the world.

A Cross-Sectional Study of Detection of Beta Globin (HBB) Haplotypes Among Beta Thalassemia Patients

Introduction

Beta-thalassemia is among the most common monogenic disorders in the Arabian Peninsula. This study aimed to investigate the β-globin (HBB) haplotypes among β-thalassemia patients in Saudi cohort which have potential implications in understanding the clinical care of patients and population genetic factors associated with β-thalassemia.

Methods

We analyzed 60 β-thalassemia patients. Male/female distribution for β-thalassemia was 58.33%/41.66%. Results of hematological parameters and indices were obtained from the database. HBB haplotyping assay was performed for four specific loci of the HBB gene cluster using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique.

Results

HBB haplotyping assay identified three novel patterns namely haplotype 1, haplotype 2, and haplotype 3 and three common African haplotypes including Benin, Senegal, and Cameron. The frequency of haplotype 1 was the highest among the studied samples (62%, n = 37) with 56.76% (n = 21) observed in males compared to 43.24% (n = 16) in females. This was followed by Senegal, haplotype 2, Benin and haplotype 3 with similar percentage, and Cameron haplotype with 18%, 12%, 3% and 2%, respectively. The relationship between these haplotypes and various hematological parameters was calculated and our study found no significant relationship (p-value >0.05).

Conclusion

Our study indicated the importance of finding out types of β-globin haplotypes as novel types being discovered. Though no statistically significant association was identified among all the haplotypes in terms of hematological parameters, Cameroon or Benin haplotypes had the mildest form because they have the highest means among all parameters. Further studies need to be carried out on a larger population to detect the frequency of each specific mutation in each haplotype among β-thalassemia patients. This would help to re-address the question of the origin(s) of the β-thalassemia.

Cost-utility of new film-coated tablet formulation of deferasirox vs deferoxamine among major beta-thalassemia patients in Iran

OBJECTIVES

Thalassemia is a hereditary disease, which caused economic burden in developing countries. This study evaluated the cost utility of new formulation of deferasirox (Jadenu) vs deferoxamine (Desferal) among B-Thalassemia-major patients from payer perspective in Iran.

METHODS

An economic-evaluation through Markov model was performed. A systematic review was conducted in order to evaluate the clinical effectiveness of comparators. Because of chelating therapy is weight-dependent, patients were assumed to be 2 years-old at initiation in first and 18 years-old in second scenario, and model was estimated lifetime costs and utilities. Costs were calculated to the Iran healthcare system through payer perspective and measured effectiveness using quality-adjusted life years (QALYs). One-way sensitivity analysis and budget impact analysis was also employed.

RESULTS

The 381 studies were retrieved from systematic searching through databases. After eliminating duplicate and irrelevant studies, 2 studies selected for evaluating the effectiveness. Jadenu was associated with an incremental cost-effectiveness ratio (ICER) of 1470.6 and 2544.7 US$ vs Desferal in first and second scenario respectively. The estimated ICER for Jadenu compared to generic deferoxamine was 2837.0 and 6924.1 US$ for first and second scenario respectively. For all scenarios Jadenu is presumed as cost-effective option based on calculated ICER which was lower than 1 gross domestic product per capita in Iran. Sensitivity analysis showed that different parameters except discount rate and indirect cost did not have impact on results. Based on budget impact analysis the estimated cost for patients using Desferal (based on the market share of brand) was 44,021,478 US$ in 3 years vs 42,452,606 US$ in replacing 33% of brand market share with Jadenu. This replacement corresponded to the cost saving of almost 1,568,872 US$ for the payers in 3 years. The calculated cost of using generic deferoxamine in all patients was 68,948,392 US$. The increase in the cost of using Jadenu for 10% of all patients in this scenario would be 934,427 US$ (1.36%) US$ at the first year.

CONCLUSIONS

Based on this analysis, film-coated deferasirox appeared to be cost-effective treatment in comparison with Desferal for managing child and adult chronic iron overload in B-thalassemia major patients of Iran.

Low IL-2 Expressing T Cells in Thalassemia Major Patients: Is It Immune Aging

Several studies have demonstrated T cell alteration and some features of immunosenescence in thalassemia major. Repeated alloimmunization converts naïve T-cells to memory cells and iron overload causes oxidative stress accelerating immune aging. To determine whether the alteration of T-cell cytokine is matched with early immune aging, the quantity of cytokine expressing T cells and their correlation to some immune aging markers were investigated. The proportion of IL2- and IFNγ expressing CD4+ and CD8+ T-cells was measured in 27 hepatitis B, C and HIV negative B-thalassemia patients and a control group aged 10-30 years, following stimulation for 6 h with streptococcus enterotoxin B and intracellular cytokine staining. This proportion then were analyzed versus the percentage of the T-cells expressing each phenotyping marker, CD27, CD28, CD57 and CCR7. CD4+ and CD8+ positive T cells expressing IL-2 were significantly lower in β-thalassemia major compared to matched controls, but not T cells expressing IFNγ. No significant difference was observed between splenectomized and non-splenectomized patients in cytokine expressing T cells. A negative correlation was noted between the percentage of T cells expressing IFNγ and T-cells expressing CD-27, but not other markers. Lower T cells expressing IL-2 may reveal the decline of naïve and central memory T cells and is likely to be a feature of early immune aging. Decreased antigenic stimulation and iron overload may help to prevent this phenomenon.

Haplotypes inside the beta-globin gene: use as new biomarkers for beta-thalassemia prenatal diagnosis in north of Iran

Background

Beta-thalassemia is common in the Mediterranean area as well as the Middle East and India. Official report in Iran revealed the average prevalence rate of carriers about 4%. More than 20 restriction fragment length polymorphisms (RFLPs) are known in the beta-globin gene cluster and used in the prenatal diagnosis (PND) services. Some of these locations may have low allele frequency and are not informative in the prenatal diagnosis. The current study aims to find new haplotypes and polymorphisms with high allele frequency in the local population.

Methods

Two thousand three hundred fifty samples (1,321 male and 1,029 female) from the northern Iran, whom suspected to be the carriers either for alpha or beta thalassemia and referred to the local diagnostic laboratory as a routine services were investigated during five years, (2010–2015). The beta-globin gene was sequenced for all samples.

Results

Heterozygosity for five SNPs in the beta-globin gene was calculated separately. 383 individuals (16.29%) showed no sign of nucleotide change in the beta-globin gene sequence. In total, codon2 (C/T) 31.72%, IVSII-16 (C/G) 31.72%, IVSII-74 (G/T) 54.71%, IVSII-81 (C/T) 19.47%, and IVSII-666 (T/C) 31.72% were seen respectively. Although all five polymorphisms showed reasonably high heterozygosity, IVSII-74 (G/T) [GG wild type (36.5%), G/T (54.71%) and TT (8.8%)] revealed the highest heterozygosity rate. Four combinations of these five SNPs were defined as new haplotypes named M1 to M4. ARMS-PCR also were designed and applied to detect IVSII-74 (G/T) nucleotide position.

Conclusions

This study represents an intragenic polymorphism, IVSII-74, a reliable position with high heterozygosity rates in Iranian population for PND analysis.

Trial registration

Retrospectively registered.

Homozygous Mutation on the β-Globin Polyadenylation Signal in a Tunisian Patient with β-Thalassemia Intermedia and Coinheritance of Gilbert's Syndrome

We report here the clinical, hematological and molecular data in a 50-year-old patient with β-thalassemia intermedia (β-TI) caused by a homozygous β⁺ mutation on the β-globin gene polyadenylation (polyA) signal (AATAAA>AAAAAA). β Haplotype analysis was accomplished by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Haplotype and framework analysis showed that this mutation is associated with the [- - - - + + +] β haplotype and framework 1 (CCGCT) (FW1). This mutation was previously reported in the heterozygous state in association with the codon 9 (+TA) mutation in a β-TI patient originating from Tunisia. To the best of our knowledge, this is the first report describing this mutation in the homozygous state. The case reported here, coinherited Gilbert's syndrome, which is characterized by hyperbilirubinemia. This conclusion was reached by the investigation of the promoter region [A(TA)_nTAA] motif of the UGT1A1 gene, showing the (TA)₆/(TA)₇ genotype.

Alteration of T Cell Subtypes in Beta-Thalassaemia Major: Impact of Ferritin Level

INTRODUCTION

Oxidative damage and regular antigenic stimulation are main factors in accelerating immunosenescence. The present study was conducted to investigate new concepts of early immunosenescence in thalassaemia patients.

MATERIALS AND METHODS

Twenty seven beta-thalassaemia major patients and a group of matched healthy volunteers aged 10-30 years in Shahrekord, Iran were recruited into the study. Ferritin level was determined and CD4 or CD8 T cells were analysed versus phenotyping markers, CD27, CD28, CD57 and CCR7, by flowcytometry. Data were analysed by Mann-Whitney and Spearman's correlation coefficient test in SPSS 11.5.

RESULTS

Absolute lymphocytosis and partial decrease in T cells were observed in the patients. CD4+CD57+ and CD4+CCR7- T cells were significantly higher, whereas CD8+CD27+ and CD8+CCR7+ T cells were partially higher in patients. A negative correlation was observed between ferritin level and number of CD8+CD27+ and CD8+CCR7+ T cells, whereas the correlation was positive between ferritin level and number of CD57+ T cells.

CONCLUSION

Moderate alteration of T cell repertoire and increase in CCR27-, CCR7-, and CD57+ T cells could reflect antigenic stimulation, decline in naïve T cells, and being closer to terminally differentiated cells. Effect of iron overload is potentially explained by positive correlation of blood transfusion and ferritin level with frequency of CD3+CD27- and that of ferritin with frequency of CD57+ T cells.

Genetic epidemiology, hematological and clinical features of hemoglobinopathies in Iran

There is large variation in the molecular genetics and clinical features of hemoglobinopathies in Iran. Studying structural variants of hemoglobin demonstrated that the β-chain variants of hemoglobin S and D-Punjab are more prevalent in the Fars (southwestern Iran) and Kermanshah (western Iran) provinces, respectively. Also, α-chain variants of Hb Q-Iran and Hb Setif are prevalent in western Iran. The molecular basis and clinical severity of thalassemias are extremely heterogenous among Iranians due to the presence of multiethnic groups in the country. β-Thalassemia is more prevalent in northern and southern Iran. Among 52 different β-thalassemia mutations that have been identified among Iranian populations, IVSII-1 G:A is the most frequent mutation in most parts of the country. The presence of IVS I-5 G:C mutation with high frequency in southeastern Iran might reflect gene flow from neighboring countries. A wide spectrum of α-thalassemia alleles has been detected among Iranians with -α(3.7 kb) as the most prevalent α-thalassemia mutation. The prevention program of thalassemia birth in Iran has reduced the birth rate of homozygous β-thalassemia since the implementation of the program in 1997. In this review genetic epidemiology, clinical and hematological aspects of hemoglobinopathies, and the prevention programs of β-thalassemia in Iran will be discussed.

Cost-utility analysis of oral deferasirox versus infusional deferoxamine in transfusion-dependent β-thalassemia patients

BACKGROUND

Deferasirox (DFX) is a novel iron chelator that has been shown to have similar efficacy and safety compared with deferoxamine (DFO) in patients with β-thalassemia. The aim of this study was to determine the cost utility of DFX versus DFO in β-thalassemia major patients from Iran's society perspective.

STUDY DESIGN AND METHODS

A Markov model has been developed to determine lifetime cost and quality-adjusted life-years (QALYs) of patients. To estimate the annual cost of each method, a cross-sectional study was conducted among two groups of patients who received DFO and DFX (n = 100 and n = 45, respectively). Also a time trade-off method was used to estimate the utility of two strategies. Finally a one-way and probabilistic sensitivity analysis was conducted to examine the strength of the results.

RESULTS

Our base-case analysis showed that estimated total lifetime costs per patient for DFX and DFO were 47,029 international dollar ($Int) and $Int143,522, respectively, while the estimated total discounted QALYs per person were 12.28 and 7.76, respectively. Calculated incremental cost-effectiveness ratio showed that DSX is a dominant therapy and its estimated lifetime net monetary benefit was $Int273,528.

CONCLUSION

We conclude that the use of DFX instead of DFO represents a cost-effective use of resources for treatment of iron overload in patients with β-thalassemia from Iran's society perspective.

Concomitant presence of endothelial nitric oxide 894T and angiotensin II-converting enzyme D alleles are associated with diabetic nephropathy in a Kurdish population from Western Iran

AIM

The present study investigated the influence of insertion (I)/deletion (D) polymorphism of the angiotensin II-converting enzyme (ACE) gene in combination with endothelial nitric oxide (eNOS) G894T polymorphism on the predisposition to diabetic nephropathy (DN).

METHODS

Using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP) method, the ACE and eNOS polymorphisms were genotyped in 72 microalbuminuric, 68 macroalbuminuric and 72 normoalbuinuric type 2 diabetes mellitus (T2DM) patients from Western Iran.

RESULTS

The presence of eNOS T or ACE D allele was not associated with increased risk of macroalbuminuria (odds ratio (OR) = 1.36, P = 0.27 and OR = 1.6, P = 0.062, respectively). However, in the presence of both alleles there was a trend towards increased risk of macroalbuminuria (fivefold, P = 0.05).

CONCLUSION

Our study indicates that the concomitant presence of both ACE D and eNOS T alleles tends to be associated with an elevation risk of macroalbuminuria compared with the presence of each polymorphism alone. This risk could be attributed to the increasing activity of ACE and angiotensin II level in the presence of D allele and decreasing NO production in the presence of T allele accelerating diabetic nephropathy.

Interaction of MTHFR 1298C with ACE D allele augments the risk of diabetic nephropathy in Western Iran

The aim of the current study was to examine the influence of interaction between polymorphisms of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C with angiotensin converting enzyme insertion/deletion (ACE I/D) polymorphism on the risk of diabetic nephropathy (DN). In a case control study using polymerase chain reaction (PCR)- and PCR-restriction fragment length polymorphism (RFLP), the presence of three polymorphisms in 140 patients with type 2 diabetes mellitus (T2DM) with nephropathy including patients with micro- and macro-albuminuria and 72 patients with normoalbuminuria from Western Iran were investigated. In the presence of both MTHFR 677 T and ACE D alleles, there was a trend toward increased risk of DN 2.68-fold (p=0.054). The possession of both MTHFR 677 T and ACE D alleles increased the risk of macro-albuminuria four times (p=0.035). The concomitant presence of both MTHFR 1298 C and ACE D alleles increased the risk of macro-albuminuria 7.8-fold (p=0.012). In addition, the risk of progression from micro- to macro-albuminuria in the presence of both alleles tended to be increased (4.1-fold, p=0.09). Our study for the first time demonstrated a synergistic effect between ACE I/D with either MTHFR C677T or A1298C polymorphism on the increased risk of DN among patients with T2DM. We found that MTHFR 1298 C strongly interacts with the ACE D allele and augments the risk of DN in our population.

Identification of three novel mutations [-41 (A>C), codon 24 (-G), and IVS-I-109 (-T)], in a study of beta-thalassemia alleles in the Isfahan region of Iran

Beta-thalassemia (beta-thal) is one of the most common autosomal recessive disorders in Iran, with more than 15,000 registered cases of thalassemia major in the country. Iran has a multiethnic society and knowledge of the mutation spectrum and regional distribution is an essential requirement for health planning and a prenatal diagnosis program. We have determined the spectrum of mutations in patients from the Isfahan region of Iran. A study of 190 chromosomes revealed 24 different mutations, including three novel ones: -41 (A>C), IVS-I-109 (-T) and codon 24 (-G). The most common mutation was IVS-II-1 (G>A) (20.5%), followed by IVS-I-5 (G>C) (11%). The findings for the Isfahan region confirm the extremely heterogeneous nature of the molecular basis of beta-thal in Iran. The results show that a strategy of using the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) for 14 of the most common mutations and DNA sequencing for the rare mutations can be used for prenatal diagnosis of beta-thal in this region.