Molecular characterization of β-thalassemia in four communities in South Gujarat—codon 30 (G → A) a predominant mutation in the Kachhiya Patel community

Seroprevalence of HBV, HCV and HIV-1 and Correlation with Molecular Markers among Multi-Transfused Thalassemia Patients in Western India

Background

Multitransfused β-thalassemia major patients are always at high risk of having Transfusion Transmitted Infections (TTIs). This study was aimed to determine the seroprevalence of HBsAg, Anti-HIV-1/2, and Anti-HCV among these patients and to correlate the same with NAT testing.

Methods

A total of 196 patients with β-thalassemia were included in the study. Patients were screened for the presence of viral markers by third-generation ELISA test as well as for viral DNA/RNA by NAT test.

Results

Among 196 multi-transfused Beta-thalassemia patients, the seroprevalence of anti-HCV was very high 100 (51.1%), however, anti-HIV1/2 was 6 (3.1%), and HBsAg were 3 (1.5%). Surprisingly similar patterns were observed in the prevalence of molecular markers, as HCV-RNA were 66 (33.7%) of the patients along with HIV-1 RNA were 8 (4.1%), and HBV-DNA were 5 (2.5%) patients. Overall eight (4.1%) patients were found to have coinfections, where two were positive for HBsAg/anti-HCV by ELISA along with 3 (1.5%) were positive for HBV-DNA/ HCV-RNA, 1 (0.5%) was positive for HIV-RNA/HBV-DNA, and 2 (1%) had coinfection of HIV-RNA/ HCV RNA by NAT testing

Conclusion

The prevalence of HCV infection among multi-transfused β-thalassemia patients is significantly higher than that of the HBV and HIV infections. This scenario should be controlled and monitored by doing regular follow-up testing schedules of such patients and also the administration of the booster dose of the HBV vaccine along with HCV treatment with antiviral DAAs.

Rare β- and δ-Globin Gene Mutations in the Pathare Prabhus: Original Inhabitants of Mumbai, India

Genetic structure of the Indian population is influenced by waves of several immigrants from West Eurasia. Therefore, genetic information of various ethnic groups is valuable to understand their origins, the pattern of migration as well as the genetic relationship between them. No genetic data is available on Pathare Prabhu, which is a small indigenous Hindu community from Mumbai, Maharashtra State, India. The aim of this study was to screen the Pathare Prabhus for hemoglobinopathies, which is a major public health problem in India. Two hundred and fifty-seven unrelated Pathare Prabhus subjects were screened for various hemoglobinopathies. Complete blood counts (CBC) were done on an automated hematology counter. High performance liquid chromatography (HPLC) was used to identify β-thalassemia (β-thal) carriers. Molecular characterization of the β gene defects was done by reverse dot-blot hybridization, amplification refractory mutation system (ARMS) and DNA sequencing. Deletional α-thalassemia (α-thal) was detected by multiplex polymerase chain reaction (PCR). Hb A₂-Saurashtra (HBD: c.301C>T) was identified by DNA sequencing; its modeling was also done. The prevalence of β-thal was 3.89%, while deletional α-thal was 5.4%. The initiation codon (ATG>ACG) (HBB: c.2T>C) was seen in eight individuals (80.0%), Hb D-Punjab (HBB: c.364G>C) and Hb A₂-Saurashtra, was found in two and one individual, respectively. A community-specific β-thal mutation was found in Pathare Prabhus in significant proportions. This information is useful in developing an algorithm for a prenatal diagnosis (PND) program.

Monogenic diseases in India

Studies on monogenic diseases are considered valuable because they give insights and expand our knowledge on gene function and regulation. Despite all the current advancement in science and technology, a deep understanding and knowledge as to why only those particular genes are affected in a disease is still vague. We also lack profound illumination as to why only certain mutations are seen in a disease. Though useful from a research perspective, a majority of these diseases are lethal resulting in death of the affected individual. Unfortunately, in the fast - growing land of India, the incidence of monogenic diseases is very high with few counter-measures in place. This article encompasses a list of all monogenic diseases ever to be reported in India with special focus on five diseases which has been stated to have the highest incidence in India. Here, we discuss about the limited research carried out in India on these high incidence monogenic diseases, the other diseases related to those genes, the range of treatments available for these diseases in India in contrast to its availability around the world and the need to develop treatment strategies to reduce the mortality and morbidity due to these rare but daunting diseases.

A multiplex ARMS PCR approach to detection of common β-globin gene mutations

BACKGROUND

β-thalassaemia is a group of inherited single-gene disorders worldwide. Each ethnic population has its own common mutations. Heterogeneity of β-thalassaemia mutations in multi-ethnic population of Surat, makes molecular diagnosis expensive and time consuming.

METHODS

Specific primers were used to differentiate four common mutations, IVS I-5 (G→C), Codon 41/42 (- TCTT), 619-bp deletion and FS 8/9 (+G), by a simple PCR involving a multiplex amplification refractory mutation system.

RESULTS

Several high prevalence β-Thalassemia trait groups constituted by Muslims, Patels, Sindhis, ModhBanias, and Mahayavanshi. Four most common mutations detected in them are IVS I-5 (G→C), Codon 41/42 (- TCTT), 619-bp deletion and FS 8/9 (+G). We identified each of these β-thalassemia mutations in multiplexed ARMS from positive control samples. Our multiplex-ARMS-PCR system was first standardized on positive DNA samples with above known four most common β-thalassemia mutations, and these positive samples had been diagnosed with β-thalassemia and also all these samples belonged to Surat ethnic groups. The system was subsequently tested on 110 blood samples from different ethnic backgrounds with unknown β-thalassemia mutations which were in all specimens.

CONCLUSION

The ARMS multiplex system was found reliable, cost effective, fast and most applicable for mutation screening of Thalassemia in Surat populations.

Mutation analysis of β-thalassemia in East-Western Indian population: a recent molecular approach

Background

β-Thalassemia is the most prevalent genetic disorder in India. Its traits and coinheritance vary from mild to severe conditions, resulting in thalassemia minor, intermediate, and major, depending upon many factors.

Purpose

The objective of this study was to identify the incidence of β-thalassemia traits, their coinheritance, and mutations, as well as to support the patients already diagnosed with β-thalassemia in East-Western Indian population for better management.

Patients and methods

Seventy-five referral cases for β-thalassemia were analyzed for various β-thalassemia traits, heterozygosity, and homozygosity conditions. Blood phenotypic parameters using cell counter and capillary electrophoresis were investigated. Analyses of eight common mutations of thalassemia in India were carried out using polymerase chain reaction-amplification refractory mutation system, end point polymerase chain reaction, and DNA sequencing methods.

Results

Of these (75) referral cases from East-Western Indian region, 68 were positive for β-thalassemia (90.67%). The majority of case types were of β-thalassemia minor (49, 65.33%), followed by HbE traits (6, 8.0%) and β-thalassemia major, including heterozygous and homozygous (5, 6.66%; 4, 5.33%) types and then HbE homozygous (2, 2.66%), as well as one each of the HbE/β-thalassemia and HbD/β-thalassemia (1, 1.34%) combination. Mutation analysis also revealed that the highest frequency of mutation was c.92+5G>C (41, 60.29%) followed by deletion 619bp (9, 13.23%) and c.79G>A (8, 11.76%) in our study group. Five cases (nos. 24, 27, 33, 58, and 71) exhibited coinheritance between β⁰/β⁺ (2), β⁰/β D (1), and c.124_127delTTCT/β⁺ or β⁰(2) affecting the Rajasthani and Gujarati populations in our study of the Western region of India.

Conclusion

We strongly recommend these Western populations for genetic screening before adopting reproductive technologies and interracial marital relations.

Control of Thalassemia in India

The β-thalassemias and sickle cell disorders pose a major health burden in the large and diverse Indian population. Education programs for awareness generation are being done by National Institutions, non-governmental organizations and Thalassemia Societies in different states. Several extensive epidemiological studies have shown that there are many non-tribal and tribal communities where the prevalence of b-thalassemia carriers is much higher (5.3 to 17.0%) than the average of 3 to 4% projected for the entire country. These variations have also been shown within small geographic regions in some states, emphasizing the need for micro mapping to estimate the true burden of disease. There are 10 to 12 centers where prenatal diagnosis for hemoglobinopathies is done and the Indian Council of Medical Research is establishing additional regional centers in states where they are most needed. Sixtyeight b-thalassemia mutations have been described so far among Indians and the knowledge on their prevalence and regional distribution has helped to undertake prenatal diagnosis in a cost effective way.