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.     

The burden of genetic disorders in India and a framework for community control

With a very large population and high birth rate, and consanguineous marriage favoured in many communities, there is a high prevalence of genetic disorders in India. An estimated 495,000 infants with congenital malformations, 390,000 with G6PD deficiency, 21,400 with Down syndrome, 9,000 with beta-thalassaemia, 5,200 with sickle cell disease, and 9,760 with amino acid disorders are born each year. The prevalence of late-onset multi-factorial disorders (including coronary artery disease, hypertension and psychiatric disorders) is also large. Due to inadequate diagnostic, management and rehabilitation facilities, the burden of these disorders is greater than in Western countries. Although genetic diseases receive little attention from the health services, research funding by the government has been liberal. Community control of common disorders like thalassaemia, Down syndrome, neural tube defects, and muscular dystrophies deserves high priority, and genetic services should be integrated into the existing primary health care and medical services. Most genetic counselling would have to be provided through training physicians who staff the district and medical school hospitals. To ensure future progress, there is a need to establish additional departments of medical genetics in medical schools.     

Community-based program for the diagnosis and prevention of genetic disorders in Cuba. Twenty years of experience

The author's experience of 20 years as director of the medical genetic services program in Cuba is presented. The setting of the infrastructure for equipment and the training of personnel for the medical genetic program began in 1981 in the city of Havana, and was progressively extended to cover the whole country in 1988. Between 1982 and 2002, 2.8 million pregnant women were tested for sickle cell carrier status, 96,000 carriers and 4,786 couples at risk were detected and offered genetic counseling and prenatal diagnosis. In the same period, the combination of maternal serum alpha-fetoprotein screening and fetal ultrasound led to the prenatal diagnosis of anomalies in several thousand fetuses. The accessibility to legal abortion, and the autonomous decisions by the majority of couples to terminate abnormal pregnancies reduced the prevalence of neural tube defects and sickle cell disease at birth by 90 and 65%, respectively, by 2002. In the span of approximately 20 years, 22,690 pregnant women at risk received prenatal chromosomal diagnosis. Newborn screening for phenylketonuria and congenital hypothyroidism was established. Genetic counseling was offered to every detected person or family at risk for genetic conditions. The network of medical genetic services established in the country received a very positive acceptance by the population. A very successful connection with the primary health care level was established.     

Attitudes toward genetic counseling in the United Arab Emirates

AIMS: To assess the level of understanding of genetic advice given in the Genetic Clinic and attitudes toward consanguineous marriages, and prenatal, abortion and preconception diagnoses. METHODS: One hundred couples underwent structured interviews, and various social and educational data, reason for referral and diagnosis and advice given were recorded. Three months later, the couples were asked open-ended questions about the perceived causation of the disease, recurrence risk, plans for births, and prenatal, abortion and preconception diagnoses. RESULTS: Half of the couples acknowledged a genetic basis for their child's condition but only 10 remembered the risk given to them. There was a high correlation between educational level and remembering the risk, and the number of healthy children and future plans for further children. Almost half preferred consanguineous marriages and only 10% agreed with prenatal diagnosis and abortion, while 75% agreed with carrier screening and preconception diagnosis in affected families. CONCLUSION: Effective genetic counseling in this community requires an informed educated population and introduction of carrier screening and preconception diagnosis in affected families.     

Preventing congenital anomalies in developing countries

The birth prevalence of congenital anomalies in developing countries is similar to that observed in developed countries. However, the health impact of birth defects is higher because of a lack of adequate services for the care of affected infants and a higher rate of exposures to infections and malnutrition. A number of successful measures for the prevention of congenital anomalies are being taken in a number of developing nations. Primary prevention programs are based on public education about preconceptional and prenatal risks. Prevention based on reproduction options includes teratogen information services and prenatal screening for fetal anomalies. In addition, programs for the detection of congenital malformations at birth, followed by early treatment, are contributing to secondary prevention. Prevention of congenital anomalies in the developing world requires: (a) good epidemiological data on the prevalence and types of birth defects and genetic disorders; (b) educating health professionals in the goals and methods of preventing birth defects at low cost but with high impact, and (c) expansion of family planning and improvement of antenatal care combined with educational campaigns to avoid the risks for birth defects. The basis for public health preventive measures should be the primary health care level. In a sizable proportion of developing countries, the stage is already set for these measures to be implemented. Required are education, political will, and proper organization and allocation of resources.     

Genetic contribution to high neonatally lethal malformation rate in the United Arab Emirates

OBJECTIVES: We examined the contribution of genetic disorders to congenital anomalies (CA) causing neonatal deaths in the Al Ain Medical District (AMD) in the United Arab Emirates (UAE) because of the high consanguineous marriage rate in the community. METHODS: Charts of all neonatal deaths in the three perinatal units, which accounted for 99% of all births in AMD (1992-2000), were studied. Data regarding pregnancy, a family history including the level of parental consanguinity, the results of genetic evaluations and neonatal outcomes were recorded as part of an ongoing malformation surveillance system. Causes of death were based on clinical, laboratory and imaging findings. RESULTS: Of the 508 neonates who died, 212 (42%) had CA, which were the leading cause of death. Forty-four percent of the CA were due to definite genetic disorders and 75% of these were single gene defects. Multisystem malformations were the commonest congenital malformations. Parental consanguinity was associated with a 2-fold increased risk of non-chromosomal multisystem malformations. CONCLUSIONS: Lethal malformations were the leading cause of neonatal deaths, and parental consanguinity was associated with an increased risk of autosomal recessive disorders. The results underscore the importance of genetic screening and counseling in strategies for further significant reductions in the neonatal mortality rate in the UAE.     

Assessment of two 'low-tech' genetic health care procedures performed by prenatal care providers in Washington state: implications for future policy development activities

Equity in health care demands that patients be treated fairly, impartially and with justice. Health care professionals and others have long been aware of the concept of equity, and the many inequities that exist in our health care system. As part of our analysis of postpartum data collected between 1993 and 1996 by the Washington Pregnancy Risk Assessment Monitoring System (PRAMS) from self-administered patient surveys, we explored equity as it pertains to two 'low-tech' prenatal genetic health care procedures: (1) whether or not prenatal care providers asked their patients about a family history of birth defects/genetic disorders, and (2) whether or not prenatal care providers talked to their patients about prenatal testing for birth defects/genetic disorders. Overall, about 80% of pregnant women reported that they had been asked about their family history of birth defects/genetic disorders, and about 85% said that their prenatal care provider(s) had talked to them about prenatal testing. Maternal characteristics associated with a lower likelihood of receiving these two low-tech genetic health care procedures appeared to be young maternal age, and low education and income levels, regardless of where women with these attributes received their prenatal care (e.g. community, migrant, health department or military health care clinics, private physicians, or health maintenance organizations).     

Preconceptional screening of couples for carriers of cystic fibrosis: a prospective evaluation of effects, costs and savings for different mutation detection methods

OBJECTIVE: The aim of this study was to perform a prospective evaluation of the effects, costs and savings of a preconceptional screening programme of couples for carriers of cystic fibrosis (CF). METHODS: A decision model for both single-entry two-step (SETS) and double-entry two-step (DETS) couple screening was constructed. Two mutation detection methods were considered: allele-specific oligonucleotide (ASO) hybridisation screening of 32 mutations, with a sensitivity of 90%, and denaturing gradient gel electrophoresis (DGGE), with a sensitivity of 98%. In our model, the following combinations were used: (1) ASO for both steps; (2) DGGE for both steps, and (3) ASO for the first step and DGGE for the second step. The model is demonstrated using figures from the Netherlands, where there is a carrier frequency of 1:30. We estimated the value of different choices and probabilities in a decision tree and determined the costs of screening for CF and the costs of the illness itself. RESULTS: We found that with most of the combinations of mutation detection methods, SETS couple screening could offer positive net savings in the Netherlands. The ASO/DGGE combination resulted in the highest net savings. DETS couple screening for all combinations, including testing with DGGE in both steps, did not show a positive cost-savings balance at all, not even with an uptake rate of 100%. The maximum number of carrier couples identified when screening 100,000 couples with the ASO/DGGE combination was 98 (SETS). This could result in about 25 fewer children born with CF each year in the Netherlands, under the following assumptions: (1) each couple has two children and 10% of couples are unable to have children; (2) of detected carrier couples, 15% decide not to have children and 85% make use of prenatal diagnosis; (3) of those fetuses diagnosed with CF, 80% are aborted, and (4) prenatal diagnosis carries a 0.75% risk of iatrogenic abortion. CONCLUSIONS: The results of this evaluation show that there are no financial objections to the preconceptional screening of couples in the Netherlands when the above-mentioned assumptions apply; thus, further evaluation can concentrate on the balance of the non-economic consequences of screening for participants and for society.     

Improving access to and utilization of genetic services in Arizona's Hispanic population

This abstract presents a model project aimed to train community lay health workers about genetics, increase cultural competency of genetic services providers, and provide local access to genetic services in primarily Hispanic communities in the state of Arizona. Health Start, a community-based prenatal outreach program, served as the basis for providing genetic education and services. A genetics training curriculum was developed and training of community lay health workers was provided. Cultural and Spanish language training was provided for all genetic services providers. Pediatric genetics outreach clinics were established in eight communities. Community-based lay health workers eagerly incorporate genetic information into their public health knowledge base, but this may not lead to acceptance of these personnel by local health care providers as sources of referrals for specialized health services such as genetics. Cultural competence training of genetic service providers is enthusiastically accepted and utilized in the provision of locally accessible genetics clinics.     

Genetic services and research in the state of Minas Gerais, Brazil

The state of Minas Gerais in Brazil has a surface of 586,528 km(2), and 18 million inhabitants. Infant mortality rate is 20/1,000, and congenital anomalies are its second cause. There are 11 medical schools where basic genetics, but not clinical genetics, is taught. Genetic services in the state include: newborn screening for hypothyroidism, phenylketonuria, sickle cell disease and cystic fibrosis; clinical-genetic diagnostic evaluation and counseling; prenatal diagnosis, fetal medicine and paternity testing. Medical genetic services and research are underdeveloped because of limitations such as lack of health policies in genetics, small number of trained specialists, little knowledge about genetics among health professionals and low reimbursement rates.     

Genetic services in Ecuador

Ecuador has a population of 12 million inhabitants, composed of a variety of ethnic groups. The majority of the population lives in rural areas. There is a severe deficiency in health services, and most diseases are associated with poor life conditions: malnutrition, parasitic diseases and infections. At the same time, however, chronic diseases, e.g. cancer, have increased in prevalence. Most genetic services are provided by the private sector, which offers clinical genetic consultations and counseling, cytogenetic analyses, a limited number of molecular and biomedical tests, and prenatal diagnosis. Genetic research is centered in the universities of important cities (Quito, Guayaquil and Cuenca). The government sponsors some university research projects but does not conduct health actions in genetics in the community. There is an incipient interest in ethic and legal issues in genetics, such as how to provide modern genomic medicine in a resource-poor country.     

Strengthening genetic services in primary care for Asian Americans and Pacific Islanders

The Association of Asian Pacific Community Health Organizations (AAPCHO) is a national membership organization of community health centers (CHCs) that serve medically underserved Asian Americans and Pacific Islanders (AAPIs) with limited English-speaking proficiency and low income. OBJECTIVES: In 1995, AAPCHO was funded for a 3-year national genetics training project to improve genetics training among primary care providers at CHCs and strengthen linkages with tertiary genetic centers (TGCs). Three model linkages between CHCs and TGCs were documented on the coordination of genetic services for medically underserved AAPIs. METHODS: Guidelines were developed for three CHCs to document their genetic programs and linkages with TGCs. In addition, one clinic conducted a mail survey to assess understanding of prenatal genetic counseling sessions by patients that visited the clinic during the past 2 years. RESULTS: Model linkages between CHCs and TGCs to improve cultural and linguistic accessibility for patients include formal coordination between the CHCs and TGCs for the delivery of genetic services and the provision of varying levels of genetic services at the CHC. From the patient survey, there was a 59% response rate among 70 surveys mailed to former patients. The survey results showed that while a majority of patients understood and recalled key genetic concepts, one-fifth of patients experienced difficulty understanding their genetic counseling sessions. CONCLUSION: Based on model linkages between CHCs and TGCs and the patient satisfaction survey results, the following strategies are recommended to improve accessibility of genetic services for medically underserved AAPIs: (1) genetics education should be developed for all levels of health center staff; (2) counseling should be culturally sensitive and focus on key issues that must be conveyed for appropriate informed consent; (3) genetics education should employ the use of translated audiovisual aids and brochures to improve understanding; (4) genetic services should be coordinated between CHCs and TGCs to provide culturally and linguistically competent care for medically underserved AAPIs, and (5) financial mechanisms should be available to support genetic testing of patients and their families with little or no coverage for genetic services.     

Screening for alpha-thalassemia-1 heterozygotes in expecting couples by the combination of a simple erythrocyte osmotic fragility test and a PCR-based method

OBJECTIVE: To develop a simple method for the prospective identification of couples at risk of homozygous alpha-thalassemia-1 (Hb Bart's hydrops fetalis) in pregnancy. METHODS: Antenatal care (ANC) women and their husbands were analyzed using a simple erythrocyte osmotic fragility (EOF) test and a PCR-based method for the detection of the mutation leading to alpha-thalassemia-1 of the Southeast Asian type (SEA). RESULTS: Heterozygosity for the alpha-thalassemia-1 (SEA) deletion was found to correlate with an EOF value <60%. For a prospective screening, ANC women and their husbands are analyzed with the EOF test and only those having a value <60% were further checked by PCR. Of 2,769 cases analyzed during a 6-month period, 24 couples in which both partners are heterozygotes could be identified for genetic counseling and prenatal diagnosis. The application of the EOF test decreased the workload for PCR by approximately 80%. CONCLUSION: Prospective screening for alpha-thalassemia-1 (SEA) heterozygotes in northern Thailand is becoming easier to realize by the combination of EOF test and PCR.     

Consumer perspectives on genetic testing, research and services for ethnoculturally diverse populations

A panel of individuals from diverse ethnocultural backgrounds and representing a variety of genetic disorders presented their consumer perspectives on genetic programs, testing and services. Their remarks emphasized how misunderstanding and miscommunication between health care professionals and many of the populations for whom they provide services can lead to unfilled genetic service needs. Panelists recommended that health care professionals become more aware and knowledgeable about the diversity of customs, beliefs and cultures of those receiving their services. Only by building a foundation of trust and mutual respect will genetic testing, research and services become more accessible to individuals from diverse populations, their families and their communities.     

Common language for measures of occurrence of congenital anomalies and genetic diseases: incidence or birth prevalence

Scientists involved in the epidemiology of congenital anomalies (including genetic diseases) use many terms to describe the occurrence of these disorders amongst births, such as 'incidence', 'prevalence' and 'rate'. Yet it is clear that often 'prevalence' is the only meaningful measure for the proportion of births affected with a certain congenital or genetic disorder. 'Incidence' and 'rate' are usually inappropriate, as the assessment of the frequency of a disorder is not a matter of following up a cohort of healthy individuals until they fall ill.     

Common autosomal recessive diseases in Oman derived from a hospital-based registry

OBJECTIVES: The local frequencies of genetic disorders in Oman apart from hemoglobinopathies are largely unknown. The aim of the present study was to evaluate birth prevalence of commonly diagnosed autosomal recessive diseases and to estimate needs and priorities of genetic services. METHODS: Analysis of the years 1993-2002 using a hospital-based registry of genetic diseases was attempted. More than 3,000 records were reviewed. Only patients with definite diagnosis were included in the analysis. Genetically determined diseases occurring less frequently than 1 in 50,000 births are not included. RESULTS: A number of rare autosomal recessive diseases are found to have a prevalence at least 1 in 50,000 livebirths. CONCLUSIONS: The data suggest that genetic diseases are important as major contributors to perinatal and childhood mortality and morbidity. The need for preventive genetic service is essential for the health of the community in Oman. Autosomal recessive diseases were frequently concentrated in specific geographical areas, which can be explained by founder effect and genetic drift. However, the hospital-based registry may present incomplete information. Further prospective studies are needed to provide more detailed data.     

Genetic services in Latin America

This special issue of Community Genetics reviews some of the most important developments in medical genetics in key countries of Latin America. Contributions to this issue were prepared for a special consultation of the World Health Organization held in Porto Alegre, Brazil, on June 19, 2003. Latin America is a region of medium- to low-income countries characterized by socioeconomic problems, with large segments of the population living in poverty and extreme disparities in the distribution of wealth. A rise in chronic diseases typical of the processes of industrialization and urbanization coexists with the persistence of nutritional and infectious diseases characteristic of poverty and underdevelopment. Over the last 2 decades of the 20th century, birth defects and genetic disorders have increased their share of morbidity and mortality, and tertiary-care-based genetic services have developed in urban areas. Although privatization of health care is eroding the public sector, the public institutions continue to be the main providers of genetic services for the bulk of the population and the leaders in research. The development of clinical genetics in the region is concentrated in tertiary-care centers in large cities, although a recent trend began extending genetic services to the community.     

Current Challenges to Appropriate Clinical Use of New Genetic Knowledge in Different Countries

Objective: To describe the challenges facing countries all over the world regarding the appropriate clinical use of genetics in their health care systems. Methods and Results: Aspects of the economic and social contexts in different countries which are of particular relevance to shaping the existing challenges are outlined. Issues which are relevant (but of different prominence) in all countries in providing genetic services are discussed. Conclusions: The challenges facing the provision of appropriate genetic services differ markedly in four major groups of countries. These challenges range from controlling inappropriate commercialization and the overuse of genetic approaches to putting in place even minimal basic community genetics services in countries where the infant mortality rate has fallen to a range where genetic and congenital disorders contribute substantially to ongoing handicap and early mortality. Copyright 2001 S. Karger AG, Basel