Prenatal diagnosis of beta-thalassemia in Egypt: implementing accurate high-tech methods did not reflect much on the outcome

Genomics in Egypt: Current Status and Future Aspects

Egypt is the third most densely inhabited African country. Due to the economic burden and healthcare costs of overpopulation, genomic and genetic testing is a huge challenge. However, in the era of precision medicine, Egypt is taking a shift in approach from “one-size-fits all” to more personalized healthcare via advancing the practice of medical genetics and genomics across the country. This shift necessitates concrete knowledge of the Egyptian genome and related diseases to direct effective preventive, diagnostic and counseling services of prevalent genetic diseases in Egypt. Understanding disease molecular mechanisms will enhance the capacity for personalized interventions. From this perspective, we highlight research efforts and available services for rare genetic diseases, communicable diseases including the coronavirus 2019 disease (COVID19), and cancer. The current state of genetic services in Egypt including availability and access to genetic services is described. Drivers for applying genomics in Egypt are illustrated with a SWOT analysis of the current genetic/genomic services. Barriers to genetic service development in Egypt, whether economic, geographic, cultural or educational are discussed as well. The sensitive topic of communicating genomic results and its ethical considerations is also tackled. To understand disease pathogenesis, much can be gained through the advancement and integration of genomic technologies via clinical applications and research efforts in Egypt. Three main pillars of multidisciplinary collaboration for advancing genomics in Egypt are envisaged: resources, infrastructure and training. Finally, we highlight the recent national plan to establish a genome center that will aim to prepare a map of the Egyptian human genome to discover and accurately determine the genetic characteristics of various diseases. The Reference Genome Project for Egyptians and Ancient Egyptians will initialize a new genomics era in Egypt. We propose a multidisciplinary governance system in Egypt to support genomic medicine research efforts and integrate into the healthcare system whilst ensuring ethical conduct of data.

Prevalence of iron deficiency anemia and beta thalassemia carriers among relatives of beta thalassemia patients in Nile Delta region, Egypt: a multicenter study

Background

Screening of β thalassemia among close relatives is more feasible in highly prevalent countries with limited resources. The purpose of this study is to determine the prevalence of β thalassemia carriers and iron deficiency anemia among relatives of β thalassemia patients in Mid Delta, Egypt.

Methods

This is a cross-sectional multi-center study conducted on 2118 relatives of patients with β thalassemia from different Egyptian governorates in the Mid Delta region. They were subjected to history taking with precise determination of geographic location, general examination, and the following investigations: complete blood counts, serum ferritin for those who showed microcytic hypochromic anemia, and high-performance liquid chromatography for those who were not diagnosed as iron deficiency anemia.

Results

The total prevalence of iron deficiency anemia among close relatives of confirmed β thalassemia patients in the Nile Delta region was 17.19%. The highest prevalence of iron deficiency anemia (45.05%) was reported in Al-Gharbia Governorate, followed by Al-Menoufia Governorate (21.67%), and the lowest prevalence was that of Al-Sharkia Governorate (4.91%). The differences were highly statistically significant (p < 0.001). β thalassemia carrier prevalence rate in the studied relatives was 35.84%, with the highest prevalence detected in Al-Sharkia Governorate (51.32%), followed by Kafr-Alsheikh and Al-Dakahilia Governorates (41.78%, 37.13%) respectively, while Al-Menoufia Governorate had the lowest prevalence rate (25.00%). These differences were also highly statistically significant (p < 0.001).

Conclusion

More than one-third of relatives of patients with β thalassemia are carriers of the disease, while 17.19% suffer from iron deficiency anemia. This study demonstrates the importance of tracing the high number of beta thalassemia carriers among relatives of patients with β thalassemia in Egypt.

The first five years of a preventive programme for haemoglobinopathies in Northeastern Iraq

OBJECTIVE

To evaluate the feasibility and effectiveness of a preventive programme for haemoglobinopathies in a single centre in Northeastern Iraq.

METHODS

Premarital screening, genetic counselling and prenatal diagnosis (PND) were implemented over a 5 year period.

RESULTS

Among a total of 108,264 screened individuals (54,132 couples), β-thalassaemia trait, δβ-thalassaemia trait, and sickle cell trait were diagnosed in 3.98%, 0.11% and 0.07%, respectively. Of 130 at risk couples (2.4/1000), 107 (82%) were available for follow up, with 105 couples (98.1%) proceeding with their marriage after counselling. In the 125 registered pregnancies in the latter couples, PND was performed in 85 (in 80 couples, uptake 76%). Selective termination was chosen in 10 of the 11 pregnancies with an affected fetus. Six affected babies were born among couples who declined PND. At the same time 30 already married couples with at least one thalassaemic child underwent PND, revealing three affected fetuses; all three pregnancies were terminated.

CONCLUSION

The programme revealed that most at risk couples diagnosed by premarital screening chose to proceed with their marriage, with 76% seeking PND followed by selective termination of an affected fetus. A 65% reduction in number of affected births was reported over the 5 year period. This regional programme could serve as a prototype for a national haemoglobinopathy prevention programme.

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.

Strategies for basic laboratory diagnostics of the hemoglobinopathies in multi-ethnic societies: interpretation of results and pitfalls

The consistent multi-ethnic migrations of the last decades have considerably changed the epidemiology of the hemoglobinopathies. Healthy carriers of these conditions are present today in many nonendemic parts of the world, and severely affected children are now born where these diseases were previously rare or unknown. Improving the competence in carrier diagnostics at the laboratory level is one of the first concerns when introducing management and primary prevention of the severe conditions in nonendemic areas. This review describes how and when carriers should be correctly diagnosed and informed. The essential technologies needed for basic carrier diagnostics in different situations are summarized in some detail, and interpretation of the results and a number of related problems are discussed. The role of the hematology laboratory is essential, particularly in nonendemic areas where the first line of health care is often insufficiently aware of hemoglobinopathy management. Carriers living in nonendemic areas can be appropriately diagnosed and informed regarding genetic risk and prevention by well-organized laboratories. Both basic and specialized diagnostics are needed for the correct treatment for the anemic carriers, for primary prevention in couples at risk and for state-of-the art care of severely affected patients.

Prenatal diagnosis for thalassaemia in Egypt: what changed parents' attitude?

OBJECTIVES

To present the current status of the prenatal diagnosis services and results from the largest thalassaemia center in Egypt treating 3000 patients. Traditionally, prenatal diagnosis has not been successful in reducing the births of affected children in Egypt, because the majority of women undergoing prenatal diagnosis continued to have affected pregnancies.

METHODS

Seventy-one pregnant mothers at risk for β-thalassaemia underwent prenatal diagnosis by chorionic villus sampling (n=57) or amniocentesis (n=14) between 11 to 14 weeks of gestation. Molecular characterization of fetal DNA by reverse dot blot hybridization and polymerase chain reaction-amplification refractory mutation system techniques was conducted in all cases.

RESULTS

Twenty-four women (33.8%) were found to have affected fetuses; 100% of these women opted to terminate the pregnancy. The change in attitude towards termination of pregnancy was related to in-depth counseling of the religious aspects towards prenatal diagnosis and termination of pregnancy. Forty-eight women (66.2%) with normal or carrier fetuses for β-thal requested human leukocyte antigen typing of the fetal material to determine if the fetus was a human leukocyte antigen match for their existing thalassaemic siblings.

CONCLUSION

This study demonstrates that prenatal diagnosis is feasible and acceptable in Egypt, a Muslim country, provided an in-depth discussion, which also addresses the religious considerations of prevention, is held with the couples.

Prenatal screening for β-thalassemia major reveals new and rare mutations in the Pakistani population

β-Thalassemia is the most common genetic disorder in Pakistan, where more than 6000 affected children are born annually, and the carrier population is around 10 million. The objective was to study β-globin gene mutations in chorionic villous biopsy samples. Prenatal screening of 383 pregnant women between 2003 and 2010 was carried out using a panel of 13 mutation primers and amplification refractory mutations system (ARMS)-PCR. In addition, DNA sequencing was used to confirm uncharacterized mutations and in some cases fetal disease status was confirmed by linkage analysis. Families enrolled in this study represented major ethnic groups in Pakistan. Of the 13 mutations tested, three mutations accounted 71% of the total, including IVS1-5(G-C)[HBB:c.92+5G>C], codon 8/9(+G) [HBB:c.27_28insG] and del 619[NG_000007.3:g71609-72227del619]. Mutations in four uncharacterized samples were later confirmed by DNA sequencing as -88(C-T)[HBB:c.-138C>G], -90(C-T)[HBB:c.-140C>T] and codon 59(+T)[HBB:c.178_179insT]. To our knowledge, this is the first report of these mutations in Pakistan. Moreover, 19.2% fetal samples were normal and 52.3% heterozygous, whereas 26.4% were affected with thalassemia major. IVS1-5:IVS1-5 was the most common genotype in fetal samples. Prenatal diagnosis of β-thalassemia using ARMS PCR is an efficient approach for reducing the burden of this disease in Pakistan. In addition, rare mutations reported in this study should be incorporated in the diagnostic strategy.

Prevention of hemoglobinopathies in Egypt

The hemoglobin disorders are the most common clinically serious single gene disorders in the world. In Egypt, beta-thalassemia is the most common type with a carrier rate varying from 5.3 to > or =9% and a gene frequency of 0.03. So, it was estimated that 1,000/1.5 million per year live births will suffer from thalassemia disease in Egypt (total live births 1,936,205 in 2006). beta-Thalassemia creates a social and financial burden for the patients' family and the Egyptian government. The high frequency of beta-thalassemia carriers with increasing rate of newly born cases is a pressing reason for the importance to develop prevention program for beta-thalassemia in Egypt. Sickle-cell disease (SCD) is not frequent in Egypt except in the Oases where the carrier rate varies from 9 to 22%. Our objectives were to provide an in-depth analysis of the current status of hemoglobinopathies in Egypt and what we need for prevention of these diseases.

Prospective and retrospective primary prevention of hemoglobinopathies in multiethnic societies

OBJECTIVES

This review emphasizes the need for adapted prevention strategies in areas where severe hemoglobin disorders are endemic and in non-endemic countries where large immigrant groups are living.

DESIGN AND METHODS

Screening versus carrier diagnostics upon medical versus ethnic indication, ethical issues associated with carrier screening, information to multiethnic carriers and practical aspects of laboratory diagnostics are discussed.

RESULTS AND DISCUSSION

School screening is a valid option but needs follow up until partner choice. Premarital carrier diagnostics upon ethnic indication needs motivated GP's and might implicate (female) stigmatization in particular cultures. Early pregnancy is the best moment regarding the motivation, but needs rapid molecular analysis when a couple at risk seeks prevention. Neonatal screening is feasible when the organization is already present for other diseases and may offer retrospective as well as prospective primary prevention when all carriers are reported. Problems to be expected while implementing neonatal screening are summarized.