Prevalence of β-Thalassemia and hemoglobin E in two migrant populations of Manipur, North East India

Prevalence of beta thalassemia carriers in India: a systematic review and meta-analysis

A large number of studies have reported that the prevalence of beta thalassemia carriers in India varies by ethnic groups. The objective of this study was to conduct a systematic review of the published studies and conduct a meta-analysis to determine the prevalence of beta thalassaemia carriers in India. A PubMed database search using keywords "beta thalassaemia AND India" identified 1088 articles of which 69 articles were included in the review. Studies using diagnostic tests and methods recommended by the International Council for Standardization in Haematology were used for calculation of pooled prevalence. Pooled prevalence was calculated using a random effects model using Review Manager version 5.3. Studies had screened five categories of populations, that is, the general population; tribal groups, communities not belonging to tribal groups, persons with anemia, and persons referred with a suspicion of hemoglobinopathy. This heterogeneity contributed to a high pooled prevalence of beta thalassemia carriers of 8.23% (95% CI 7.36-9.10). Sub-group analysis however yielded 3.74% (95% CI 2.52-4.97) pooled prevalence of beta thalassemia carriers in the general population. It was 4.6% (95% CI 3.2-6.2) among tribal groups. Quality of prevalence studies was limited by methodological issues including non-random sampling methods, heterogeneity of population types screened, and lack of use of recommended diagnostic cut-offs. Prevalence of beta thalassemia carriers was similar in tribal populations and the general population, indicating the need to further investigate the prevalence of beta thalassemia carriers in tribal groups.

Prevalence and Management of β-Thalassemia in India

India bears a huge burden of hemoglobinopathies, and the most prevalent is thalassemia. The different types of thalassemia include minor, major and intermedia, based on the α/β-globin chain inequality. This review aimed to understand the current prevalence of thalassemia in different regions of India and communities affected by it, along with the management of β-thalassemia major (β-TM) and β-thalassemia (β-thal) minor patients. A comprehensive electronic search for relevant articles was conducted using two databases, i.e. PubMed and Science Direct. Articles published in English from India between January 2009 and September 2021 were included. Studies from other countries, genetic and molecular characterization studies, and articles published in other languages were excluded. The prevalence of β-thal trait in Central India ranged between 1.4 and 3.4%, while 0.94% β-TM was reported among the patients with anemia. In South India, the prevalence of β-thal trait was between 8.50 and 37.90% and β-TM was reported to be between 2.30 and 7.47%. Northern and Western Indian states had a higher thalassemic burden. In Eastern India, tribal populations had a higher prevalence of β-thal trait (0.00-30.50%), β-TM (0.36-13.20%) and other hemoglobinopathies [Hb E (HBB: c.79G>A)/β-thal] (0.04-15.45%) than nontribal populations. Additionally, scheduled castes, scheduled tribes and other backward classes of low socioeconomic status and low literacy rates were affected by β-thal. Almost all Indian states reported β-thal; however, it is mostly concentrated in eastern and western parts of the country. Well-integrated strategies and effective implementation are needed at State and National levels to minimize the burden of β-thal.

Undiagnosed haemoglobinopathies among pregnant women attending antenatal care clinics in Pune, India

Pregnant women with iron deficiency and those who are carriers of haemoglobinopathies present with anaemia of varying severity. There is no antenatal screening for haemoglobinopathies in India. The objective of this study was to determine the prevalence of undiagnosed haemoglobinopathy carriers in a random sample of pregnant women attending antenatal care clinics in Pune city, India. Biobanked DNA of 360 randomly selected pregnant women was genotyped for six common mutations and two common haemoglobin variants, HbS and HbE. Odds ratios (OR) with 95% confidence intervals were computed to determine association of carrier status with socio-demographic, haematological and clinical characteristics. The prevalence of undiagnosed haemoglobinopathy carriers was 6.3% (95% CI 4.2-9.4%) of which 3.3% (95% CI 1.9-5.7%) were beta thalassaemia carriers. There was an increased odds that beta thalassaemia carriers had moderate anaemia (OR 10.59, 95% CI 1.15-96.90). This study reveals the high prevalence of undiagnosed haemoglobinopathy carriers among pregnant women, indicating the need to immediately implement carrier screening and genetic counselling services across the country.

Inter-regional differences in body proportions in Indian children and adolescents-a cross-sectional multicentric study

Background: Sitting height (SH) and leg length (LL) help in assessing disproportionate growth. Anthropometric dissimilarity has been observed in different ethnicities.Aim: To (1) study sitting height and body proportions in children from different regions of India; and (2) compare sitting height and body proportions with data from other countries.Subjects and methods: This was a cross-sectional multicentric observational study, where 7961 (4328 boys) 3-18 year old children from five regions (north, south, east, west and central) were measured (height, weight and SH).Results: Boys from north India and girls from central India were taller and heavier (mean height 153.2 ± 18, 146.4 ± 11), while western boys and girls were the shortest (131.1 ± 20.7, 129.8 ± 19.5) (p < 0.05 for all). The highest SH was observed in the north (79.2 ± 8.5) and the lowest in the west (68.8 ± 9.1). Mean SH:LL ratio was highest in children from the northeast (1.13) followed by those from western, northern and central India (1.12, 1.10 and 1.07, respectively) and the ratio was the least in children from south India (1.05) (p < 0.0.5 for all except northeast and west). Children from the north and west were similar to the Dutch, children from the south were similar to South (black) Africans and the north-eastern children were similar to Chinese children.Conclusion: There were inter-regional differences in body proportions; similarities in body proportions with children from other ethnicities may throw light on the migration history of Indian people.

Newborn Screening for Hemoglobinopathies and Red Cell Enzymopathies in Tripura State: A Malaria-Endemic State in Northeast India

Hemoglobinopathies are a group of inherited single gene disorders. There are reports on hemoglobin (Hb) variants identified in the tribal and non-tribal populations of Tripura State in northeastern India. This study aimed to determine the spectrum of hemoglobinopathies and enzymopathies by newborn screening in Tripura State and assess the extent of neonatal jaundice. A total of 2400 cord blood samples were collected and analyzed by high performance liquid chromatography (HPLC). Further confirmation of any abnormal HPLC was done by DNA analysis. The samples were also screened for deficiency of enzymopathies, glucose-6-phosphate dehydrogenase (G6PD) deficiency and pyruvate kinase. Of 2400 cord blood samples screened, 225 (9.3%) were Hb E (HBB: c.79G>A) heterozygotes, 80 (3.3%) were Hb E homozygotes and one carried Hb E-β-thalassemia (β-thal). Other Hb abnormalities were also detected including 15 Hb S (HBB: c.20A>T) heterozygotes, two Hb D-Punjab (HBB: c.364G>C) heterozygotes and two compound heterozygotes for Hb D-Punjab and Hb E. Of the 80 homozygous Hb E babies, four were non-tribal and 76 babies were tribal, and 225 patients carried Hb E trait, 141 were tribal, while 84 were non-tribal. Of 40 G6PD deficient babies identified, 13 had coinherited Hb E and two babies had pyruvate kinase deficiency. α Genotyping was performed in 162 affected babies, 50 of them carried α gene deletions. Newborn screening programs for Hb E, other hemoglobinopathies and G6PD deficiency must be encouraged in the malaria-endemic northeastern region of India. Drug-induced hemolysis can also be avoided by screening for G6PD deficiency at birth.

Hematological Characterizations and Molecular Diagnostic Aspects of Hb Wiangpapao [α44(CE2)Pro→Ser (α1), CCG>TCG; HBA1: c.133C>T], a New α-Globin Variant Found in a Pregnant Thai Woman

We report the hematological parameters and provide a rapid molecular analysis method for detection of Hb Wiangpapao [α44(CE2)Pro→Ser, CCG>TCG; HBA1: c.133C>T], a new α-globin variant found in a pregnant Thai woman. Her red cell indices were measured by an automated blood counter. The results were: red blood cell (RBC) count 4.03 × 10¹²/L, Hb 13.1 (g/dL), packed cell volume (PCV) 0.39 L/L, mean corpuscular volume (MCV) 97.0 fL, mean corpuscular hemoglobin (Hb) (MCH) 32.5 pg, mean corpuscular Hb concentration (MCHC) 33.4 g/dL, and RBC distribution width (RDW) 9.4%. The Hb typing by high performance liquid chromatography (HPLC) showed 13.6% abnormal Hb at a retention time of 2.20 min. that was difficult to distinguish from Hb A. On the capillary electrophoresis (CE) electropherogram, this hemoglobinopathy peak did not separate from the Hb A peak. DNA sequencing showed a C>T transition at the first position of codon 44 (CCG>TCG) of the α1-globin gene that led to a substitution of proline for serine. This mutation has not been recorded in the public databases. Therefore, we named it Hb Wiangpapao as it was first discovered in the Wiangpapao District, Chiang Rai, Thailand. The multiplex allele-specific polymerase chain reaction (ASPCR) for detection of Hb Wiangpapao was developed and revealed a 510 bp specifically amplified fragment. The better understanding of hematological characterizations and the newly developed multiplex ASPCR for diagnosis of Hb Wiangpapao are useful for genetic counseling and family education.

Hematological and Molecular Characterization of Hb J-Buda [α61(E10)Lys → Asn, AAG > AAT]

Hemoglobin (Hb) J-Buda [α61(E10)Lys → Asn, AAG > AAT] is a very rare α-chain variant found in South-East Asia. We analyzed hematological parameters and provided a rapid molecular analysis method for detection of this hemoglobinopathy in two Thai women who had severe microcytic anemia with Hb and MCV <70 g/L and 80 fL, respectively. The HPLC revealed an abnormal Hb peak eluted ahead of HbA at retention time of 1.91-1.98 min. On CE, the abnormal Hb peak was observed at the electrophoretic zone 12 which corresponded to Hb Bart's. The DNA sequencing revealed the AAG → AAT mutation at codon 61 for Hb J-Buda on one allele of the α1-globin gene. The developed Allele-specific PCR (ASPCR) showed the 455 bp amplified fragment from Hb J-Buda allele. Thus, understanding of hematological characterizations and the developed ASPCR for diagnosis of Hb J-Buda are essential for genetic counseling of this hemoglobinopathy.

Detection of Co-inheritance of Hb Hope and Hb Constant Spring in Three Thai Samples by Capillary Electrophoresis

The diagnosis of co-inheritance of Hb Hope [β136(H14)Gly → Asp, GGT > GAT] and Hb constant spring [Hb CS; α142, Term → Gln (TAA > CAA IN α2)] by high performance liquid chromatography (HPLC) is difficult because Hb Hope has a HPLC elution pattern similar to that of Hb Pyrgos, Hb New York, Hb Kodaira, and Hb Phimai. Moreover, the Hb CS mRNA, as well as the gene product, are unstable and present at a low level in peripheral blood. We report the use of a capillary electrophoresis (CE) for diagnosis of co-inheritance of Hb Hope and Hb CS in 3 Thai females who had mild anemia with Hb and Hct varying from 91-114 g/L to 0.28-0.36 L/L, respectively. Hb Hope eluted with a retention time of 125-140 s (Zone 10) of CE electrophoregram. Furthermore, the peak of Hb CS at the retention time of 245-250 s (Zone 2) was observed in these samples. In addition, the manual analysis by taking the non-black area under both peaks of HbA and Hb Hope (inverted V) into account provided the corrected Hb CS levels which are useful in screening of heterozygote or homozygote for Hb CS. Thus, the CE method provides an accurate diagnosis of Hb Hope and Hb CS which is useful in genetic counseling, prevention and control programs for these hemoglobinopathies.

Potential Effects of Silymarin and Its Flavonolignan Components in Patients with β-Thalassemia Major: A Comprehensive Review in 2015

Major β-thalassemia (β-TM) is one of the most common inherited hemolytic types of anemia which is caused as a result of absent or reduced synthesis of β-globin chains of hemoglobin. This defect results in red blood cells lysis and chronic anemia that can be treated by multiple blood transfusions and iron chelation therapy. Without iron chelation therapy, iron overload will cause lots of complications in patients. Antioxidant components play an important role in the treatment of the disease. Silymarin is an antioxidant flavonoid isolated from Silybum marianum plant. In the present study, we reviewed clinical and experimental studies investigating the use of silymarin prior to September 1, 2015, using PubMed, ISI Web of Knowledge, Science Direct, Scopus, Ovid, and Cochrane Library databases and we evaluated the potential effects of silymarin on controlling the complications induced by iron overload in patients with β-TM. Based on the results of the present study, we can conclude that silymarin may be useful as an adjuvant for improving multiple organ dysfunctions.