The Changing Trends in Prenatal Diagnosis of Hemoglobinopathies in India: The Quest of a Single Center to Reduce the Burden of Disease over Three Decades.

The ß-thalassemias and sickle cell disorders pose a considerable health burden in India. Of the more than 10,000 annual births of children with a severe hemoglobinopathy, only around 10.0% are managed optimally. Thus, genetic counseling and prenatal diagnosis (PND) is a valid option for a large and diverse country. Our center was one of the first to initiate PND and we present our experience over 30 years to evaluate the impact of awareness in changing the trends of PND of hemoglobinopathies. Both second and first-trimester diagnoses were undertaken by fetoscopy/cordocentesis and globin biosynthesis/high-performance liquid chromatography (HPLC) analysis of fetal blood and chorionic villus sampling (CVS) and DNA analysis. Over 30 years, 3478 couples (first trimester: 2475; second trimester: 1003) from all over India were offered PND. The number of couples coming in the first trimester increased significantly over each decade and couples coming prospectively increased from 2.5 to 18.4%. A cost-effective stepwise approach was used for molecular analysis. Eight hundred and one fetuses (23.0%) were affected and all except three couples opted for termination of these pregnancies. Genetic counseling and PND is the only way to reduce the burden of disease. With awareness, there was a shift from second trimester to first trimester PND over each decade, with an increasing number of couples coming during the first pregnancy. There are only 15 to 20 centers in India offering PND. We have compared our study with other reports on PND from different regions in India.

Clinical manifestations of sickle cell disease in India: misconceptions and reality.

PURPOSE OF REVIEW: In the past, milder clinical manifestations of sickle cell disease (SCD) have been described from India. However, recent data from some parts of India suggest that the severity of the disease can be compared to that of African phenotypes. This review therefore describes the varied clinical manifestation of SCD, the success of newborn screening programme, prenatal diagnosis and low dose hydroxyurea therapy in India. RECENT FINDINGS: The varied clinical manifestations such as anemia, vaso-occlusive crisis, acute chest syndrome, renal involvement, stroke and so on vary from one part of the country to the other and also among different communities of India. Strategies for improving quality of life and controlling of SCD have been suggested. Certain factors other than genetics also play an important role in clinical manifestation of the disorder. SUMMARY: The clinical diversity of SCD is described. The natural history of SCD in India is unfolding from newborn screening programme. The use of low-dose hydroxy urea therapy both in adults and children has brought down the incidences of crisis and provides great relief to the patients. The tailor-made programme for India as regards the control and management has been discussed.

Spectrum of hemoglobinopathies among the primitive tribes: a multicentric study in India.

We evaluated the spectrum of hemoglobinopathies among the primitive tribal groups from 4 states in India. A total of 15,200 individuals from 14 primitive tribal groups were studied by automated high-performance liquid chromatography. The hemoglobin S (HbS) allele frequency varied from 0.011 to 0.120 and the ß-thalassemia allele frequency from 0.005 to 0.024. It is interesting to note that a very high HbS allele frequency was observed among the Dravidian (0.060-0.120) and Indo-European (0.060-0.076) as compared with Austro-Asiatic (0.011-0.022) speaking tribal groups. Although statistical analysis of the data did not show any ethnic differences within the states, regional differences were observed between the states for both HbS and ß-thalassemia traits. HbS was found to be the most common hemoglobinopathy followed by ß-thalassemia. A health plan for identifying sickle-cell homozygotes in the neonatal period with proper medical intervention is desirable.

A study of the PfNT3 in Plasmodium falciparum

Previous genetic studies demonstrated that survival and proliferation of Plasmodium falciparum parasites is dependent on salvage of essential purines from the host. Plasmodium falciparum, the causative agent of the most lethal form of human malaria lacks the enzymes required for de novo synthesis of purines. Analysis of the hypothetical nucleoside/nucleobase transporter protein, the gene product of PfNT3 (PF14_0662) gene in P. falciparum parasites was carried out by localisation, in view of a novel chemotherapeutic target. Immunoblotting, immunofluorescent and immunoelectron microscopic localization of PfNT3 was demonstrated using polyclonal antiserum in in vitro cultured Plasmodium falciparum parasites, propagated in human red blood cells. PfNT3 protein, the translated product of PfNT3 gene was detected in intraerythrocytic ring, trophozoite, and schizont stages. PfNT3 was localized primarily to the PPM (Parasite Plasma Membrane). The endogenous PfNT3 putative nucleoside transporter with the predominant location to the parasite plasma membrane may serve not only as routes for targeting of purine analogs/cytotoxic agents into the intracellular parasite but may also serve as drug targets. Being genome encoded the vital transporter protein can be prevented from expression by silencing of the gene, validating it to be a novel drug target.

Guidelines for screening, diagnosis and management of hemoglobinopathies.

The ß-thalassemias and sickle cell disorders are a major health burden in India. Diagnosis and management of these disorders both in adults and in newborns using appropriate approaches and uniform technology are important in different regions of a vast and diverse country as India. In view of a National Thalassemia Control Program to be launched soon, a need was felt for guidelines on whom to screen, cost-effective technologies that are to be used as well as for establishing prenatal diagnosis programs in regional centers. Newborn screening for sickle cell disorders is in its infancy in India and uniform approaches need to be followed. Also, included are guidelines for monitoring and managing patients who are now growing older and need comprehensive care as well as management of complications of the disease.

Interaction of iron deficiency anemia and hemoglobinopathies among college students and pregnant women: a multi center evaluation in India.

Although iron deficiency anemia is very common in India, systematic large studies on the prevalence and hematological consequences of iron deficiency among carriers of ß-thalassemia (ß-thal) and other hemoglobinopathies are lacking. A multi center project was undertaken to screen college/university students and pregnant women for iron deficiency anemia and various hemoglobinopathies. Fifty-six thousand, seven hundred and seventy-two subjects from six states, Maharashtra, Gujarat, Karnataka, West Bengal, Assam and Punjab, were studied. Iron deficiency anemia was evaluated by measuring zinc protoporphyrin (ZPP) and hemoglobin (Hb) levels, while ß-thal and other hemoglobinopathies were detected by measuring the red cell indices and by Hb analysis using high performance liquid chromatography (HPLC). College boys (2.2%), college girls (14.3%) and antenatal women (27.0%) without any hemoglobinopathies had iron deficiency anemia. Among the ß-thal carriers, the prevalence of iron deficiency anemia was 17.3% in college boys, 38.1% in college girls and 55.9% in pregnant women, while in the Hb E [ß26(B8)Glu→Lys; HBB: c.79G>A] carriers, it was 7.3% in college boys, 25.4% in college girls and 78.0% in antenatal women. In individuals with Hb E disease, the prevalence of iron deficiency anemia varied from 31.2-77.3% in the three groups. A significant reduction in Hb levels was seen when iron deficiency anemia was associated with hemoglobinopathies. However, the Hb A2 levels in ß-thal carriers were not greatly reduced in the presence of iron deficiency anemia.

A novel autologous stem cell procedure for the treatment of aplastic anaemia using reprogrammed mature adult cells: a pilot study.

BACKGROUND & OBJECTIVES: Aplastic anaemia is a life threatening rare bone marrow failure disorder. The underlying haematopoietic cellular deficit leads to haemorrhage, infection and severe anaemia. The treatment of choice for this haematological condition is allogeneic bone marrow transplantation from fully matched HLA sibling. Though this procedure is curative in the majority of young patients with aplastic anaemia, extending this benefit to older patients or those lacking a family donor remains a major challenge. Herein, the safety and efficacy of infusing autologous retrodifferentiated haematopoietic stem cells (RHSC) into four patients with aplastic anaemia without the use of any pre- or post-conditioning regimen including immunosuppression is described. METHODS: Un-mobilized, mononuclear cells were harvested from four patients with acquired aplastic anaemia by aphaeresis. Mononuclear cells of patients were cultured with purified monoclonal antibody against the monomorphic regions of the beta chain of MHC class II antigens (Clone CR3/43) for 3 h, to obtain autologous RHSC. Autologous RHSC were washed and infused into the four patients without the use of any pre- or post-conditioning regimen. Thereafter, the efficacy (engraftment) of autologous RHSC was assessed in these patients. RESULTS: Following single infusion of the autologous RHSC, two of the four patients with aplastic anaemia become transfusion independent for more than seven years. Karyotyping and G-banding analysis prior and post-procedure in all patients remained the same. INTERPRETATION & CONCLUSIONS: The findings of this pilot study demonstrated the functional utility of reprogrammed fully differentiated adult cells into pluripotent stem cells with extensive repopulation potentials in a human setting and without any pre- or post-conditioning regimen, including immunosuppression. This autologous approach of stem cell creation may broaden the curative potentials of stem cell therapy to a wider population of patients with aplastic anaemia, including many patients suffering from other haematological and non-haematological disorders.

Genetic counselling in tribals in India.

Genetic counselling in tribals unlike general population residing in cities and near villages is a difficult task due of their lower literacy and poor socio-economic status. However, sustained effort is essential with a close interaction in the local language, certain misbeliefs need to be removed gradually taking into account their socio-cultural background. The present communication deals with our experience in counselling for haemoglobinopathies during Neonatal Screening Programme undertaken for sickle cell disease in Kalahandi district of Orissa and Community Screening Programmes in primitive tribes of India in four States viz. Orissa, Gujarat, Tamil Nadu and Maharashtra. Counselling during neonatal screening programme was very well accepted demonstrating the benefit to the small babies as regards the morbidity. Premarital marriage counselling was also accepted by them. The success rate as followed up for 5 years is almost 50 per cent, the limitation being long follow up. Genetic counselling in these areas has to be continuous to achieve success and therefore the need for setting up of permanent centres in the tribal areas in India.

Restriction fragment length polymorphism (RFLP) of the X chromosome linked glucose-6-phosphate dehydrogenase (G6PD) locus in India.

STUDY: Haplotypes linked to glucose-6-phosphate dehydrogenase (G6PD) genotypes were defined by studying six intragenic restriction fragment length polymorphisms (RFLPs) in 141 G6PD deficient and 252 normal chromosomes. RESULTS: Only four of the 64 possible haplotypes were observed, indicating marked linkage disequilibrium. All the G6PD deficient mutations were associated with either haplotype I or VII, which are similar to the common G6PD B variant observed in the present study except the G6PD Namoru mutation which corresponded to mainly haplotype VIIa where a Nla III restriction site was created due to this mutation. CONCLUSION: The limited number and low haplotype diversity probably indicates a strong selective pressure on the G6PD gene.

Epidemiology of beta-thalassaemia in Western India: mapping the frequencies and mutations in sub-regions of Maharashtra and Gujarat.

Although the average frequency of beta-thalassaemia carriers in India is 3-4% and the prevalent mutations have been studied, no micromapping has been done. This is the first attempt to provide an accurate estimate of the frequencies of beta-thalassaemia and the expected annual births of homozygous children in different districts of Maharashtra and Gujarat in Western India as well as to determine the molecular heterogeneity in different sub-regions in these states. A total of 18 651 individuals were screened for haemo-globinopathies and mutations were characterized in 1334 beta-thalassaemia heterozygotes. There was an uneven distribution of the frequencies of beta-thalassaemia, varying from 1.0% to 6.0% and 0% to 9.5% in different districts of Maharasthra and Gujarat. The rate of homozygosity per 1000 births annually was 0.28 in Maharashtra and 0.39 in Gujarat. The three most prevalent beta-thalassaemia mutations in Maharashtra were IVS 1-5(G-->C), Codon 15(G-->A) and Codon 30(G-->C) (87.9%) while in Gujarat they were IVS 1-5(G-->C), 619 bp deletion and Codon 5(-CT) (68.5%). These data will help to develop adequate programmes for control and care where they are most needed. They also emphasize the importance of subgroup micromapping for determining the health burden of a common genetic disease.

Clinical, hematologic and molecular variability of sickle cell-ß thalassemia in western India.

BACKGROUND: Sickle cell-ß thalassemia (HbS-ß thalassemia) is a sickling disorder of varying severity, which results from compound heterozygosity for sickle cell trait and ß thalassemia trait. The present study was undertaken to determine the genetic factors responsible for the clinical variability of HbS-ß thalassemia patients from western India. MATERIALS AND METHODS: Twenty-one HbS-ß thalassemia cases with variable clinical manifestations were investigated. The α and ß globin gene clusters were studied by molecular analysis. RESULTS: Thirteen patients showed milder clinical presentation as against eight patients who had severe clinical manifestations. Four ß thalassemia mutations were identified: IVS 1-5 (G→C), codon 15 (G→A), codon 30 (G→C) and codon 8/9 (+G). α thalassemia and XmnI polymorphism in homozygous condition (+/+) were found to be common among the milder cases. The ß(S) chromosomes were linked to the typical Arab-Indian haplotype (#31). Framework (FW) linkage studies showed that four ß thalassemia mutations were associated with different ß globin gene frameworks. Linkage of codon 15 (G→A) mutation to FW2 is being observed for the first time. CONCLUSION: The phenotypic expression of HbS-ß thalassemia is not uniformly mild and α thalassemia and XmnI polymorphism in homozygous condition (+/+) are additional genetic factors modulating the severity of the disease in the Indian subcontinent.

Current concepts in platelet transfusion.

This is the era of component therapy. Therefore there is a need for rational use of platelet concentrate. Lot of knowledge has been added recently in the field of platelet specially about the platelet rich plasma and its application in clinical practice. The current review focuses on improvement in preparation of platelet rich plasma, the procedure to make the same more safe and its rational use. Furthermore newer aspects of platelet concentrate use in surgical practice and for regenerative medicine has also been discussed. It also covers some progress and hurdles in preparation of platelet substitutes.

Regional heterogeneity of beta-thalassemia mutations in the multi ethnic Indian population.

To determine the frequencies of beta-thalassemia mutations in different states of India and to compare this with the available data in Asian Indians for a comprehensive catalogue of molecular defects in the Indian population. beta-thalassemia mutations were characterized in 2456 heterozygotes using reverse dot blot hybridization, ARMS and DNA sequencing. 36 beta-thalassemia mutations were characterized from 18 different states in India. Seven mutations were common, accounting for 95.8% of mutated alleles. Marked regional diversity was seen in different parts of the country. Among the tribal populations, only 2 mutations (IVS I-5 (G-->C) and CD15 (G-->A) accounted for over 90% of mutant alleles. A compilation of all the studies in Asian Indians reported so far showed the presence of 63 mutations in the Indian population. This large study adds to the existing data to give a detailed account of the molecular basis of beta-thalassemia in India. This information is important for establishing prenatal diagnosis programmes in different states in India as well as other countries in which there is a major influx of Indian immigrants.

Hydroxyurea in sickle cell disease--a study of clinico-pharmacological efficacy in the Indian haplotype.

There is clinical variability in the presentation of sickle cell disease among Indians. Vaso-occlusive crisis is common among non-tribal patients. Hydroxyurea, induces fetal hemoglobin (HbF) synthesis and reduces the clinical severity of sickle cell disease but individual patients have a variable response. This study was undertaken to investigate the efficacy and safety of hydroxyurea in Indians with severe manifestations where the beta(s) gene is linked to the Arab-Indian haplotype and is associated with higher HbF levels. Seventy-seven patients (29 adult sickle homozygous, 25 pediatric sickle homozygous, 23 adult sickle beta-thalassemia) selected for hydroxyurea therapy were evaluated for clinical, hematological, biochemical and genetic parameters and were followed for 24 months. Ninety-eight point seven percent of the sickle chromosomes were linked to the Arab-Indian haplotype, 27% of patients had associated alpha thalassemia and 65% were Xmn I +/+. Seventy-eight percent of the patients had no further crises after starting hydroxyurea. This effect was accompanied by a significant increase in HbF (p<0.001), but this increase was variable in individual cases. There was also an increase in gamma gene mRNA expression in the few cases so studied. Hemoglobin levels increased significantly (p<0.001) resulting in the cessation of blood transfusions. Leucopoenia was observed in one patient. Hydroxyurea was effective in reducing the clinical severity in Indian patients who initially had higher HbF levels and the presence of ameliorating factors, such as alpha-thalassemia and the Xmn I polymorphism. Hydroxyurea therapy with careful monitoring can thus change the quality of life of Indians with sickle cell disease.

Molecular characterization of delta beta-thalassemia and hereditary persistence of fetal hemoglobin in the Indian population.

delta beta-Thalassemia (delta beta-thal) and hereditary persistence of fetal hemoglobin (HPFH) are heterogeneous disorders characterized by elevated levels of Hb F in adult life. The two disorders should not be considered as unambiguously separate entities but rather as a group of disorders with a variety of partially overlapping phenotypes. This study was undertaken to determine the hematological and molecular characteristics of high Hb F determinants among Indians. A gap-polymerase chain reaction (gap-PCR)-based approach was used for molecular characterization of high Hb F phenotypes. Fifty-five unrelated individuals were studied. The molecular findings were correlated with the hematological data. DNA analysis identified the deletion-inversion (G)gamma((A)gamma delta beta)(0)-thal in 15 cases (27%) and the HPFH-3 (Indian deletion) determinant in 26 cases (47.2%) and the Vietnamese/Chinese determinant (27 kb deletion) in five cases (9%), which is being reported for the first time from India; 16% (nine cases) of the samples remained uncharacterized. This study emphasizes that delta beta-thal and HPFH determinants are common in India. Molecular analysis will aid in understanding genotype-phenotype correlations and will facilitate prevention and control programs of thalassemia and hemoglobinopathies in this region.