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

Global distribution of β-thalassemia mutations: An update

One excellent illustration of how a single gene abnormality may result in a spectrum of disease incidence is the incredible phenotypic variety of β-thalassemia, which spans from severe anemia and transfusion needs to an utterly asymptomatic sickness. However, genetic causes of β-thalassemia and how the anemia's severity might be altered at various stages in its pathophysiology have been well investigated. There are currently known to be more than 350 mutations that cause genetic disease. However only 20 β thalassemia mutations account for more than 80% of the β thalassemia mutation across the globe due to phenomenon of geographical clustering where each population has a few common mutations together with a varying number of rare ones. Due to migration of the population, the spectrum of thalassemia mutation in changing from time to time. In this review, efforts are made to collate β globin gene mutations in different countries and populations.

Spectrum of Beta-Thalassemia Mutations in Potential Carriers with Microcytic Hypochromic Anemia from Mazandaran and Golestan, Northern Provinces of Iran

Introduction

β-Thalassaemia is the most common genetic disorder and is considered as a major public health concern in Iran. Different countrywide studies have shown a heterogeneous mutational basis of β-thalassaemia with different frequencies in each area. This study is aimed at investigating the common and rare mutations in Mazandaran and Golestan, northern provinces of Iran.

Methods

5425 microcytic and hypochromic individuals were investigated from Mazandaran and Golestan provinces. From these, 1323 beta carrier or affected individuals were selected where 938 persons were from Mazandaran and 385 people were from Golestan province, respectively.

Result

53 different mutations were identified, IVSII-1 (G>A) was the most common (59.14%) followed by Cd 22/23/24 (-7 bp) (5.34%), Cd 8 (-AA) (4.93%), Cd30 (G>A) (4.00%), and IVSI-5 (G>C) (3.70%) with a total of 77.11% in Mazandaran Province, respectively. In Golestan Province, IVSI-5 (G>C) was the most frequent (44.62%) followed by IVSII-1 (G>A) (27.18%), Cd 15 (TGG>TAG) (4.36%), Fr 8/9(+G) (3.85%), and Cd 8(-AA) (2.05%) with a total of 82.06%, respectively. From the 53 different mutations, 22 numbers have been observed in both provinces. Two deletions of the beta gene named Sicilian and Asian-Indian have been detected in Mazandaran with a frequency of 0.72% each.

Conclusion

The 53 different mutations identified in this study were the most ever reported mutations in the country. Due to diversity of different ethnic groups, there are many varieties of mutation in beta globin gene in Iran. It could be assumed that both founder effect and natural selection caused by migration from neighboring areas have complemented each other to produce the high frequency of unique alleles within each region.

Diagnostic Performance of 10 Mathematical Formulae for Identifying Blood Donors with Thalassemia Trait

OBJECTIVE

To compare the diagnostic performance of 10 mathematical formulae for identifying thalassemia trait in blood donors.

METHODS

Compete blood counts were conducted on peripheral blood specimens using the UniCel DxH 800 hematology analyzer. Receiver operating characteristic curves were used to evaluate the diagnostic performance of each mathematical formula.

RESULTS

In the 66 donors with thalassemia and 288 subjects with no thalassemia analyzed, donors with thalassemia trait had lower values for mean corpuscular volume and mean corpuscular hemoglobin than subjects without thalassemia donors (77 fL vs 86 fL [P < .001]; 25 pg vs 28 pg [P < .001]). The formula developed by Shine and Lal in 1977 showed the highest area under the curve value, namely, 0.9. At the cutoff value of <1812, this formula had maximum specificity of 82.35% and sensitivity of 89.58%.

CONCLUSIONS

Our data indicate that the Shine and Lal formula has remarkable diagnostic performance in identifying donors with underlying thalassemia trait.

Genetic attributes of Iranian cystic fibrosis patients: the diagnostic efficiency of CFTR mutations in over a decade

Objectives: Cystic fibrosis (CF) is the most prevalent autosomal recessive disorder among Caucasians. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause this pathology. We, therefore, aimed to describe the CFTR mutations and their geographical distribution in Iran. Method: The mutation spectrum for 87 families from all Iranian ethnicities was collected using ARMS PCR, Sanger sequencing, and MLPA. Results: Mutations were identified in 95.8% of cases. This dataset revealed that the most frequent mutations in the Iranian population were F508del, c.1000C>T, c.1397C>G, c.1911delG, and c.1393-1G>A. In addition, we found weak evidence for Turkey being the possible geographical pathway for introducing CFTR mutations into Iran by mapping the frequency of CFTR mutations. Conclusion: Our descriptive results will facilitate the genetic detection and prenatal diagnosis of cystic fibrosis within the Iranian population.

Rare and New Mutations of B-Globin in Azari Population of Iran, a Considerable Diversity

Background

Thalassemia, as the most common single-gene genetic disorder, is related to a defect in the synthesis of one or more hemoglobin chains. More than 200 mutations have been identified in the β-globin gene. Globally, every susceptible racial group has its own specific spectrum of the common mutations that are well-known to a particular geographic region. On the other hand, varying numbers of diverse rare mutations may occur.

Materials and Methods

The subjects of the study included 2113 heterozygote or homozygote β-thalassemia cases selected among couples who participated in the Iranian national thalassemia screening program from January 2011 to November 2019. Molecular characterization of the β-thalassemia mutation was initially carried out by the amplification-refractory mutation system-polymerase chain reaction (ARMS-PCR) technique for common mutations, followed by sequencing, Gap PCR, and Multiple ligation-dependent probe amplification (MLPA) methods - in cases not detected by the ARMS-PCR.

Results

The existence of 39 rare and new point mutations and 4 large deletions were described in our cohort. Sicilian (-13,337bp) deletion, CD36/37 (-T), and CD15 TGG>TGA were encountered more often than the others in a decreasing order, in terms of frequency. The least frequent mutations/deletions were deletion from HBD exon 1 to HBB promoter, 619 bp deletion, Deletion from up HBBP1-Exon3 HBBP1 and up HBB-0.5Kb down HBB, CAP+8 C>A, CD37 (G>A), CD6 (-A), IVSI-2 (T>C), IVSII-705 T>G, and IVSII-772 (G>A). Each occurred once. Five mutations/variants were also determined which have not been reported previously in Iran.

Conclusion

According to the findings of the study, the Northwestern Iranian population displayed a wide variety of thalassemia allelic distributions. Identification of rare and new mutations in the β-thalassemia in the national population is beneficial for screening programs, genetic counseling, and prenatal diagnosis.

Hb Narges Lab, a Novel Hemoglobin Variant of the β-Globin Gene

In this study, we describe a new missense variant on the β-globin gene in a heterozygous form in a female individual. Standard methods were used to determine red blood cell indices and perform hemoglobin analyses. Molecular studies were performed on the genomic DNA isolated from peripheral blood cells. Beta-globin genes were amplified and sequenced. We report a novel mutation on the β-globin gene (HBB), c.134 C>T; p.S44F variant, in the heterozygote state which was detected in a female of Persian ethnic origin in the Khuzestan province, southern Iran, that we named Hb Narges Lab (HbNL) variant. This mutation was predicted to be disease-causing in all except one in silico prediction tools. This variant was reported for the first time worldwide, had no shown hematological abnormalities but should be considered when inherited in the compound heterozygous form with β- thalassemia (β0-thal) carrier, which might result in the phenotype of thalassemia intermedia.

Prevalence of Depression among Iranian Patients with Beta-Thalassemia Major: A Systematic Review and Meta-analysis

BACKGROUND

Patients with beta-thalassemia (BT) are susceptible to psychological disorders such as depression. The present study was conducted to estimate the pooled prevalence of depression among patients with BT in Iran.

METHODS

Domestic and international databases were searched for relevant articles published from 1991 until June 2019. We searched international databases such as Scopus, ISI, and Embase; Iranian databases such as SID, Magiran, and IranDoc; and Google Scholar and PubMed search engines. The MeSH keywords used were "depression", "mental health", "depressive disorder", "thalassemia", "beta-thalassemia major", "prevalence", "epidemiology", and "Iran". Relevant cross-sectional or cohort studies were included in the analysis. Cochran's Q test and the I² index were used to assess heterogeneity. The pooled prevalence and its 95% confidence interval (CI) were calculated using "metaprop" commands in Stata 14. In cases, where the I² statistic was greater than 50%, the random-effects model was used.

RESULTS

Eighteen eligible studies were included. The pooled prevalence of depression was 42% (95% CI: 33% to 52%), whereas the pooled prevalence of mild, moderate, severe, and extremely severe depression was 16% (95% CI: 11% to 22%), 13% (95% CI: 9% to 18%), 13% (95% CI: 9% to 17%), and 3% (95% CI: 0% to 8%), respectively. The pooled prevalence of depression in moderate- and high-quality studies was 45% (95% CI: 29% to 61%), and 39% (95% CI: 27% to 51%), respectively.

CONCLUSION

The high prevalence of depression highlights the urgent need for the establishment of interventions for the prevention, early detection, and treatment of depression among Iranian patients with BT.

Following the Trace of HVS II Mitochondrial Region Within the Nine Iranian Ethnic Groups Based on Genetic Population Analysis

The Iranian gene pool is seen as an important human genetic resource for investigating the region connecting Mesopotamia and the Iranian plateau. The main objective of this study was to explore gene flow in nine Iranian ethnic/subpopulation groups (402 samples) by examining mtDNA HVS2 sequence variations. This then allowed us to detect mtDNA HVS2 sequence mutations in two independent thalassemia and cystic fibrosis patient sample groups. The patient groups did not explicitly belong to any of the aforementioned nine subpopulations. Across all subpopulations, the haplogroups B4a1c3a, H2a2a1, N10b, H2a2a2, and J1 were seen to be predominant. High haplogroup diversities along with admixture of the exotic groups were observed in this study. The Arab subpopulation was shown to be independent from the others. It was revealed that there is a far distant relationship between Arab and Azeri groups. The thalassemia patient group, represented an almost random sample of most Iranian ethnic groups, and revealed few significant differences (P < 0.05) in their HVS2 sequence. It turned out that the IVS II-I (G → A) mutation in the thalassemia β-globin gene was highly significant. Since the thalassemia patients in the present study represent many unique haplotypes, we can begin to comprehend the importance of mtDNA with this disease and the necessity for more studies in this context.

Prevalence of occult hepatitis C virus infection in beta-thalassemia major patients in Ahvaz, Iran

Occult hepatitis C virus infection (OCI) is defined by the presence of HCV RNA in peripheral blood mononuclear cells (PBMCs) and liver tissue cells despite the absence of HCV RNA in plasma. Currently, OCI is classified into two types: seropositive OCI (anti-HCV positive and serum HCV RNA negative) and seronegative OCI (anti-HCV and serum HCV RNA negative). Beta-thalassemia is described as a blood disorder that decreases the synthesis of hemoglobin. Repeated blood transfusion is the standard treatment for patients with beta-thalassemia major (BTM), and this increases the risk of exposure to infectious agents. The aim of this study was to investigate the prevalence of OCI among BTM patients. Plasma and PBMCs were collected from 90 BTM patients who were referred to Shafa Hospital in the city of Ahvaz and were screened for HCV antibody using a commercial ELISA kit as the first step. Next, nested RT-PCR was performed on extracts of plasma and PBMCs. HCV RNA from positive PBMCs was sequenced, the sequences were aligned, and a phylogenetic tree was constructed to determine their relationship to reference sequences retrieved from the GenBank database. Seventy-nine out of 90 patients (87.8%) were negative for HCV Ab (seronegative), while 11 patients (12.2%) were seropositive. HCV RNA was found in PBMCs of four patients (66.7%) who were negative for HCV Ab (seronegative) and two patients (33.3%) who were positive for HCV Ab (seropositive). HCV RNA was not detected in plasma samples from these six patients. Six out of 90 BTM patients (6.7%) had OCI. HCV genotyping revealed that all six patients were infected with HCV subtype 3a. We found a high frequency of OCI in BTM patients, which warrants more attention, considering the importance of this infection. Further studies are needed to determine the actual prevalence of OCI in BTM patients in Iran.

The Frequency of Beta-Thalassemia Mutations among Carriers in Dezful City, Southwest Iran

The article's abstract is not available.  

Bayesian spatial modeling of transfusion-dependent β-thalassemia incidence rate in Fars Province, Southern Iran

BACKGROUND

Using maps and spatial analysis are technologies to evaluate the magnitude and spatial distribution of disease in epidemiology investigations. We aimed to conduct a Bayesian spatial analysis on epidemiologic data of transfusion-dependent β-thalassemia (TDT) patients.

METHODS

In this cross-sectional study, data of all TDT patients diagnosed during 1955-2018 in all counties of Fars Province were obtained from data registry of the Organization of Special Diseases of Shiraz University of Medical Sciences in Shiraz, Fars Province, Iran. Besag, York, and Mollie's (BYM) model was used for mapping.

RESULTS

The estimated relative risk ranged from 0.23 to 1.66 for TDT patients. The highest and lowest relative risks of TDT were observed in Larestan located in Southern and Abadeh in Northern Fars Province respectively.

CONCLUSIONS

Determining the accurate geographical distribution of a chronic disease such as β-thalassemia can be an essential prerequisite in allocation of regional health system resources.

Prevalence and Genetic Analysis of α- and β-Thalassemia and Sickle Cell Anemia in Southwest Iran

This prospective study assessed the prevalence and genetic analysis of α- and β-thalassemia and sickle cell anemia (SCA) in Southwest Iran. Hematological indices were measured in 17,581 couples living in Khuzestan Province, Southwest Iran. Individuals with mean corpuscular volume <80, mean corpuscular hemoglobin <27, hemoglobin A2 ≥3/5 were considered as β-thalassemia traits. Prevalence of minor β-thalassemia, α-thalassemia, SCA, iron deficiency anemia, and silent thalassemia were respectively identified in 995 (5.6%), 1169 (6.65%), 1240 (7.05%), 911 (5.18%), and 1134 (6.45%) individuals using a multiplex amplification refractory mutation system, and direct DNA sequencing of globin genes. Three codons IVS-II-1 (G → A; 26%; n = 13), IVS-I-1 (G → T; 16%; n = 8), and IVS-I-110 (G → A; 14%; n = 7) were the most frequent mutants and IVS-II-1 was the most common β-thalassemia mutation. Also, based on a gap-polymerase chain reaction assay, genotype frequencies of α-globin mutations were -α^{3.7 kb} (50%; n = 25), Med/αα^thal (12%; n = 6), and -α4.2/αα (10%; n = 5), which were the most frequent deletion mutants (72% in total). The most common deletion (50%) was -α^{3.7 kb}. Our data suggest that the population of Southwest Iran is at high risk of α- and β-thalassemia caused by these deletion mutants and SCA. Our findings will be useful for developing an efficient control program and genetic counseling.

Narrating ethnicity and diversity in Middle Eastern national genome projects

Most Middle Eastern populations outside Israel have not been represented in Western-based international human genome sequencing efforts. In response, national-level projects have emerged throughout the Middle East to decode the Arab, Turkish and Iranian genomes. The discourses surrounding the 'national genome' that shape scientists' representation of their work to local and international audiences evoke three intersecting analytics of nationalism: methodological, postcolonial and diasporic. Methodologically, ongoing human genome projects in Turkey and Iran follow the population logics of other national and international genome projects, for example justifying research with reference to projected health benefits to their fellow citizens. Meanwhile, assumptions about and representations of ethnicity and diversity are deeply inflected by local histories of scientific development and nationalist politics. While Iranian geneticists have transformed this paradigm to catalog national genetic diversity through a discourse of 'Iranian ethnicities', Turkish geneticists remain politically constrained from acknowledging ethnic diversity and struggle to distance their work from racialized narratives of Turkish national identity. Such nationally-framed narratives of genomic diversity are not confined to their original contexts, but travel abroad, as demonstrated by a US-based genome project that articulates a form of Iranian-American diasporic nationalism.

Prevalence of β-Thalassemia Mutations among Northeastern Iranian Population and their Impacts on Hematological Indices and Application of Prenatal Diagnosis, a Seven-Years Study

BACKGROUND AND OBJECTIVE

β-thalassemia results from a diverse range of mutations inside the hemoglobin subunit β (HBB) gene. In a study of β-thalassemia carriers and some of their at-risk fetuses in the Khorasan province of Iran, we aimed to recognize the most common mutations in the region. We also investigated a possible link between these mutations and some of the relevant hematological indices.

METHODS

Amplification-refractory mutation system-PCR (ARMS-PCR) was used to detect the typical HBB mutations among 1593 individuals, suspected of having a mutated HBB allele from March/2011 to January/2018. Sanger sequencing of HBB had been performed, where ARMS-PCR was uninformative. In some cases, reverse dot blot was utilized. Analysis of variance was used to compare parametric variables.

RESULTS

Among 1273 β-thalassemia carriers, the prevalence of the mutations were reported as follows: IVS-I-5 (42.03%), IVS-II-1 (11.23%), codons 8/9 (4.79%), codon 44 (4.56%), codon 15 (3.53%), Los Angeles (2.91%), codon 5 (2.75%), IVS-I-110 (2.51%), -88 (2.20%) and other mutations were less than 2% of all of the reported mutations. 644 conceptions were subjected to prenatal diagnosis, using chorionic villus sampling. 118 cases were reported as normal. 352 cases were detected as carriers. 174 cases were diagnosed as affected. There was a significant difference in mean corpuscular volume and hemoglobin A2 levels between the nine most commonly reported mutation types (p<0.001).

CONCLUSION

This study makes a reliable guide for β-thalassemia diagnosis in the region. The possibility of a correlation between HBB mutations and hematological indices opens a gate of future investigations.

β-Thalassemia Distribution in the Old World: an Ancient Disease Seen from a Historical Standpoint

Background

Haemoglobinopathies constitute the commonest recessive monogenic disorders worldwide, and the treatment of affected individuals presents a substantial global disease burden. β-thalassaemia is characterised by the reduced synthesis (β⁺) or absence (β^o) of the β-globin chains in the HbA molecule, resulting in accumulation of excess unbound α-globin chains that precipitate in erythroid precursors in the bone marrow and in the mature erythrocytes, leading to ineffective erythropoiesis and peripheral haemolysis. Approximately 1.5% of the global population are heterozygotes (carriers) of the β-thalassemias; there is a high incidence in populations from the Mediterranean basin, throughout the Middle East, the Indian subcontinent, Southeast Asia, and Melanesia to the Pacific Islands.

Aim

The principal aim of this paper is to review, from a historical standpoint, our knowledge about an ancient disease, the β-thalassemias, and in particular, when, how and in what way β-thalassemia spread worldwide to reach such high incidences in certain populations.

Results

Mutations involving the β-globin gene are the most common cause of genetic disorders in humans. To date, more than 350 β-thalassaemia mutations have been reported. Considering the current distribution of β- thalassemia, the wide diversity of mutations and the small number of specific mutations in individual populations, it seems unlikely that β-thalassemia originated in a single place and time.

Conclusions

Various processes are known to determine the frequency of genetic disease in human populations. However, it is almost impossible to decide to what extent each process is responsible for the presence of a particular genetic disease. The wide spectrum of β-thalassemia mutations could well be explained by looking at their geographical distribution, the history of malaria, wars, invasions, mass migrations, consanguinity, and settlements. An analysis of the distribution of the molecular spectrum of haemoglobinopathies allows for the development and improvement of diagnostic tests and management of these disorders.

Revisiting a Complex Rearrangement Involving a 619 Base Pairs Deletion, 6 Nucleotide Insertion Followed by a A > G Substitution Causing β°-Thalassemia

One of the prevalent inherited blood disorders is thalassemia syndrome that characterized by reduction (β+) or absence (β0) of β globin chain synthesis. The β globin (HBB) gene map in the short arm of chromosome 11 and most of the mutations in this gene are single nucleotide substitutions, insertions or deletions of nucleotides. Nucleotide sequence analysis of a partially deleted β-globin gene from an Iranian carrier of β-thalassemia displayed a complex rearrangement involving a 619 base pairs (bp) deletion. This rearrangement had originally been named as the 619 bp deletion and later on as the 619 bp deletion with a 7 bp insertion. In our study, using by single chain sequencing, we have shown that the actual rearrangement involves a 619 bp deletion, a 6 bp insertion followed by a G > A substitution deleting the exon 3 of the β-globin gene. This clarification has to be inserted into the relevant databases as some of them still site the original 619 bp deletion with wrong breakpoints.

Psychological Aspects in Children and Adolescents With Major Thalassemia: A Case-Control Study

BACKGROUND

Thalassemia is an inherited blood disease. It is a serious public health problem throughout the Mediterranean region, the Middle East and the Indian subcontinent, as well as in Southeast Asia.

OBJECTIVES

Thalassemia is an inherited blood disease. It is a serious public health problem. In this study we assessed psychological aspects in Iranian children and adolescents with thalassemia major.

PATIENTS AND METHODS

In this case-control study sixty healthy subjects aged 7-18 years and Sixty Patients with confirmed diagnosis of major thalassemia were enrolled. After obtaining informed consent from parents of all participating thalassemia patients and healthycontrols, we assessed psychological aspects and quality of life by Pediatric Quality of LifeTM (PedsQL™), Strengths and Difficulties Questionnaires (SDQ), State and Trait Anxiety, Children's Depression Inventory (CDI).

RESULTS

The results of this study indicate that there are significant changes in depression, anxiety, QOL and behavioral screening between children with thalassemia major compared with healthy subjects by means of both parents and children reports. According to the results, children with thalassemia major have more psychological problems than healthy ones. Patients with thalassemia have a lower QOL than their peers (P = 0.001), the rate of depression is higher in this group (P = 0.015), Also behavioral problems in these children are more than healthy subjects (P = 0.009).

CONCLUSIONS

We recommend appropriate treatment and counseling procedures in addition to specific treatment of thalassemia. According to the results we suggest to establish pediatric psychiatric clinics beside thalassemic clinics to cure psychological aspects of the disease.

Seroepidemiology of human T-cell lymphotropic virus among Iranian adult thalassemic patients

BACKGROUND

A large number of transfusion-dependent thalassemic patients is at a substantial risk for transfusion-transmitted infections. Human T-cell lymphotropic virus (HTLV) is a blood-borne pathogen and can be transmitted via cellular products. We aimed to evaluate the seroprevalence of HTLV in transfusion-dependent thalassemic patients referred to Tehran Adult Thalassemia Clinic.

METHODS

From 2008 to 2010, 257 transfusion-dependent thalassemic patients who referred to Tehran Adult Thalassemia Clinic were enrolled. The seroprevalence of HTLV, hepatitis B virus (HBV), hepatitis C virus (HCV), and HIV were assessed using enzyme-linked immunosorbant assay (ELISA). Also, the samples with positive result for anti-HTLVAb (by ELISA) were reassessed using Western blot for HTLV.

RESULTS

Among the 257 transfusion-dependent thalassemic patients who were tested for anti-HTLVAb, 29 (11.3%, 95% CI = 7.8-15.6%) were found to be anti-HTLVAb positive by ELISA and Western blot. No case was detected to be HBsAg positive, whereas 16% had HBV seroconversion criteria, and more than 95% had anti-HBsAb in their sera. Also, 103 (40.1%) patients were HCV seropositive, 13 (5.1%) patients of which were co-infected with HCV/HTLV. Among the HTLV-infected patients, 44.8% were co-infected with HCV, whereas 39.5% of HTLV-seronegative individuals were HCV mono-infected (P > 0.05).

CONCLUSION

This study showed that transfusion-dependent thalassemic patients were in higher risk for transmission of different blood-borne pathogens such as HTLV. The screening of HTLV in Iranian blood donors is recommended.

The selenium status in thalassemia patients in South East of iran

INTRODUCTION

There are limited reports about selenium status in major thalassemia patients. The aim of this study is evaluation of selenium status in patients with major thalassemia south east of Iran with large sample size and wide range of age. This study compared selenium status with other sites of the world.

METHODS

In this study 369 cases that had major thalassemia for more than 5 years were enrolled in the study. Selenium level was measured in all eligible patients after 12 hours fasting by graphite enstrum furnace atomic absorption spectrometry in south east of Iran in 2012.

RESULTS

Of 369 cases, 333 eligible patients were evaluated. Mean age was 15.63±7.4 years. One hundred ninety two cases were male and others were female (141 Cases). About 27% (90) of the cases were 5-10 years-old, 24 % (80) were 10-15 years-old and 49% were more than 15 years-old. Iron chelator in 62.2% was Dessferrioxamine, in 15.5% was Deferiprone and in 22.3% was combination of Dessferioxamine and Deferiprone. Totally 85 cases (25.52%) had Selenium deficiency, 35.43% (118 cases) had normal levels and 39 %(130 cases) had selenium excess.

CONCLUSION

Our study on 333 major thalassemia cases documented variable status of selenium from deficiency to higher than normal levels. It was different with other reports in the world.

Impact of β-globin mutations on outcome of matched related donor hematopoietic stem cell transplantation for patients with β-thalassemia major

The clinical outcome of hematopoietic stem cell transplantation (HSCT) for patients with β-thalassemia major (β-TM) can be affected by several factors. We investigated the influence of β-globin gene mutation in patients with β-TM on the clinical outcome of HSCT and conducted a prospective study of consecutive β-TM patients who underwent allogeneic HSCT at our center. Among 87 included patients, 62 (71%) had homozygous and 25 (29%) had compound heterozygous β-globin gene mutations. Intervening sequence II-1 appeared to be the most common mutation, with an occurrence rate of 33% in β-globin alleles. With a median follow-up of 12 months, the thalassemia-free survival and overall survival probabilities were 83% (standard error, 4%) and 90% (standard error, 3%), respectively. Overall survival was not found to be associated with the β-globin gene mutation status, but thalassemia-free survival was significantly improved in patients with homozygous mutations compared with patients with compound heterozygous mutations in univariate (91.2% versus 64.0%, P = .009) and multivariable (hazard ratio, 3.83; P = .014) analyses. This is the first report on the impact of β-globin mutation status on the outcome of β-TM after allogeneic HSCT and helps to better illustrate the course and prognosis of β-TM after transplantation.

Global migration and the changing distribution of sickle haemoglobin: a quantitative study of temporal trends between 1960 and 2000

BACKGROUND

Changes in the geographical distribution of genetic disorders are often thought to happen slowly, especially when compared with infectious diseases. Whereas mutations, genetic drift, and natural selection take place over many generations, epidemics can spread through large populations within a few days or weeks. Nevertheless, population movements can interfere with these processes, and few studies have been done of their eff ect on genetic disorders. We aimed to investigate the eff ect of global migration on the distribution of the sickle-cell gene-the most common and clinically significant haemoglobin structural variant.

METHODS

For each country, we extracted data from the World Bank’s Global Bilateral Migration Database about international human migrations between 1960 and 2000. We combined this information with evidence-based estimates of national HbS allele frequencies, generated within a Bayesian geostatistical framework, to analyse temporal changes in the net numbers of migrants, and classified countries with an index summarising these temporal trends.

FINDINGS

The number of international migrants increased from 92.6 million in 1960, to 165.2 million in 2000. The estimated global number of migrants with HbS increased from about 1.6 million in 1960, to 3.6 million in 2000. This increase was largely due to an increase in the number of migrants from countries with HbS allele frequencies higher than 10%, from 3.1 million in 1960, to 14.2 million in 2000. Additionally, the mean number of countries of origin for each destination country increased from 70 (SE 46) in 1960, to 98 (48) in 2000, showing an increasing diversity in the network of international migrations between countries. Our index of change map shows a patchy distribution of the magnitude of temporal changes, with the highest positive and negative values scattered across all continents.

INTERPRETATION

Global human population movements have had a substantial eff ect on the distribution of the HbS gene. Population movements can create a long-term burden on health-care systems. Our findings, which emphasise countries in which migration fluxes are changing the most, should increase awareness about the global burden of haemoglobinopathies and encourage policy makers to implement specific public health interventions, such as screening programmes and genetic counselling.

FUNDING

Wellcome Trust, European Research Council, Bill & Melinda Gates Foundation, National Institute of Allergy and Infectious Diseases-National Institutes of Health, the Research and Policy for Infectious Disease Dynamics program, Fogarty International Center.

Increased efficiency in geographic ancestry assignment and human identification by combining lineage profiles: The case of the Iranians

OBJECTIVES

This research is a first empirical attempt to quantify the increase of the among-groups variance and the probative value of a DNA evidence when combining profiles based on markers with uniparental inheritance.

METHODS

Yfiler and HVS-I panels of loci were analyzed in 130 healthy unrelated males from six Iranian native groups.

RESULTS

A separate analysis of DNA profiles at the two lineage markers failed to detect a population substructure, whereas maximum levels of genetic diversity (HD = 1) and discrimination capacity (DC = 1) were obtained by combining the two profiles.

CONCLUSIONS

When combined, the forensic efficiency of routinely used panels of lineage markers can be largely sufficient to resolve cases of geographic ancestry and human identification even in genetically homogeneous populations.