European Journal of Cardiovascular Medicine

Hemoglobinopathies include a spectrum of inherited abnormalities in hemoglobin structure or synthesis, with a wide range of clinical outcomes, from asymptomatic to patients with mild to life-threatening symptoms. Globally, these disorders represent a significant genetic burden, particularly in regions with high consanguinity and limited access to medical care (1) . In India, hemoglobinopathies such as sickle cell disease and thalassemia are highly prevalent, especially among tribal and socio-economically disadvantaged populations.

Tribal communities in India are particularly vulnerable due to geographical isolation, lack of awareness, and limited access to healthcare services. Researchers over the past two decades have highlighted the high prevalence of sickle cell trait, sickle cell disease, and β-thalassemia traits among various tribal groups. Balgir (2000) reported that hemoglobinopathies were a major public health concern among tribal populations in central and eastern India, with sickle cell trait prevalence ranging between 5–35% depending on the tribe (2) . Further investigation by Verma et al. (2002) reinforced the regional variation in hemoglobinopathy burden, suggesting the need for localized screening strategies (3) .Colah et al. (2005) emphasized the use of advanced diagnostic techniques such as High-Performance Liquid Chromatography (HPLC) for accurate detection and quantification of hemoglobin variants in large-scale screening programs (4) . Subsequent studies by Patel et al. (2010) in Gujarat demonstrated the utility of HPLC in effectively diagnosing compound hemoglobinopathies in tribal areas (5) . A multicentre study by Gorakshakar and Colah (2013) underlined that hemoglobinopathies in tribal regions remain under diagnosed and underreported, particularly in remote and resource-limited settings (6). Recent work by Kaur et al. (2014) in Odisha and neighboring states found a continued high burden of hemoglobin disorders in tribal children, with over 50% of them having at least one abnormal hemoglobin variant (7) . These findings collectively point to an urgent need for targeted screening, especially in tertiary care centers located near tribal regions, where accurate diagnostic facilities like HPLC can be utilized.

Aim and Objectives:

The present study was undertaken to evaluate the pattern and prevalence of hemoglobinopathies in the tribal population attending a tertiary care center in Paderu, Andhra Pradesh. The aim is to generate reliable epidemiological data using High-Performance Liquid Chromatography (HPLC), to aid in the development of effective public health strategies, and to support early diagnosis and genetic counseling programs in tribal communities.

This was a prospective cross-sectional study conducted over a period of six months, from January 2025 to June 2025, in the Department of Pathology, Government Medical College and Hospital, Paderu, Alluri Sitarama Raju (ASR) District. Institutional ethical committee approval was taken for the study. A total of 900 cases were investigated using the High-Performance Liquid Chromatography (HPLC) technique to identify and quantify various hemoglobin variants among the tribal population.

Sample Collection:

EDTA blood samples were collected from patients with suspected hemoglobinopathies. These included individuals referred from primary health centers with a positive sickling test, as well as parents and siblings of diagnosed patients who were also screened for hemoglobinopathies.

HPLC Analysis:

HPLC was performed using the BIO-RAD D-10 analyzer. The results were tabulated and analyzed accordingly.

Inclusion Criteria:

·         Patients of all ages with anemia and clinical suspicion of hemoglobinopathy attending out-patient departments including ante-natal screenings.

·         Individuals with a family history of hemoglobinopathies.

·         Cases referred by the Pathology Department after a review of peripheral blood smears and/or a positive sickling test.

·         Cases referred by the community health workers with a positive sickling strip test from nearby PHCs, Sub-centers and people screened as a part of the National Sickle Cell Anemia Elimination Mission(NSCAEM). 

Exclusion Criteria:

·         Patients who had received a blood transfusion within the last three months were excluded from the study.

Gender Distribution: In this study, out of total 900 cases, 65.8% were female and 34.2% were male, indicating a higher proportion of female participants.

Table: Gender-wise Distribution of Hemoglobinopathies

Age-Wise Distribution and Patterns of Hemoglobinopathies

A total of 794 subjects (88.22%) out of 900 were found to have abnormal hemoglobin patterns through HPLC analysis either as a trait, disease, or compound heterozygous states and remaining 106 subjects showed normal Hb pattern (11.78%). The age-wise distribution of different hemoglobinopathies is summarized in the table below with exclusion of normal subjects.

Overall Burden of Hemoglobinopathies: Sickle Cell Trait (SCT) was the most prevalent finding, seen in 520 cases (65.5%), suggesting a high carrier frequency in the studied population. Sickle Cell Anemia (SCA) accounted for 76 cases (9.6%), while Sickle + β-Thalassemia was detected in 182 individuals (22.9%).Other conditions such as β-Thalassemia Trait (BTT) (1.5%), HbD with β-Thal (0.12%), β-thalassemia Major (0.12%) and HPFH (0.25%) were relatively rare.

Age-wise Concentration: The 1–10 years age group showed the highest number of hemoglobinopathy cases constitute 33.5% (n=266), predominantly SCT and Sickle + β-Thal , followed by 11–20 years (24.8%) and 21–30 years (18.6%).Together, individuals aged ≤30 years represent 76.9% of all hemoglobinopathy cases

Table: Age Group-wise Distribution of Hemoglobinopathies (n=794)

SCT prevalence declines with increasing age, indicating early diagnosis through pediatric screening or potential underreporting in older age groups. Sickle + β-Thalassemia cases were mainly distributed among the younger population (<30 years), with the highest concentration in the 1–10 age group. SCA was more frequently observed in the 11–30 years age range, which aligns with the natural history and clinical manifestation period of the disease. HPFH was detected exclusively in the 11–20 years age group. A single rare case of HbD + β-thalassemia was identified in the 31–40 years group.

The sharp decrease after 30 years reflects lower survival into adulthood among undiagnosed or severe cases. Under diagnosis in older age groups is due to lack of screening or due to subtle symptoms.

Hemoglobin Levels and Diagnostic Categories:

In the present study out of 900 cases we could retrieve Hb% for only 214 cases and analyzed them based on the Hb levels and HPLC spectrum. Most patients (57.9%) had Hb levels between 7–10 gm%, indicating moderate anemia. This group had the highest number of SCT (Sickle Cell Trait) cases (63), as well as Sickle β Thalassemia (48), both of which can present with mild to moderate anemia. Only 1 case of SCA (Sickle Cell Anemia) was in this group—likely a less severe phenotype or under treatment.

Table: Hemoglobin Levels and distribution of Diagnostic Categories:

Severely low Hb (<7%) was found in 18.7% of patients. This group had a higher concentration of Sickle β Thalassemia (13 cases) and SCT (13 cases), suggesting that co-inheritance or complications may lead to severe anemia. 2 SCA cases were found here, which is consistent with the known severe anemia typically seen in SCA.

Higher Hb levels (>10%) were seen in 23.4% of cases. Majority were SCT (35 cases) – consistent with the trait form, which is often asymptomatic or mildly symptomatic. Some Sickle β Thalassemia (10 cases) also appeared in this range, likely reflecting milder genetic variants. No SCA cases were observed in this range, which aligns with the expectation that SCA typically results in more severe anemia.

Normal HPLC with low Hb was seen in a total 26 cases. These patients had normal HPLC findings despite anemia, indicating the possibility of nutritional deficiencies (e.g., iron, folate, B12), Chronic diseases, Early stages of hemoglobinopathy not yet detectable by HPLC.

In the present study we could collect blood groups for a total of 225 patients out of the 794 patients diagnosed with Hemoglobinopathies.

On analyses the most common blood groups involved are B+ve, A+ve and O+ve constituting approximately 30 percent each. Most hemoglobinopathy cases (94%) occur in Rh-positive blood groups and the Sickle Cell Trait (SCT) is the most common disorder across all blood groups.SCA and Sickle + β-Thalassemia are highly prevalent in A+ve and O+ve groups.

Table: Blood Group wise distribution of Hemoglobinopathies

Community-wise Distribution of Hemoglobinopathies

Out of a total of 794 subjects diagnosed with hemoglobinopathies during the study period, community background was identified in 764 patients. These patients belonged to both tribal and non-tribal communities, with a predominant representation from tribal populations.

The findings highlight the need for targeted community-based interventions, particularly in tribal-dominant regions such as the ASR district. Establishing routine hemoglobinopathy screening, genetic counseling, and public health education among these vulnerable groups is essential to reduce the disease burden and prevent intergenerational transmission.

This distribution clearly demonstrates a marked predominance of Hemoglobinopathies among tribal populations, with over 98% of confirmed cases arising from these communities. The high burden in the Bagatha and Valmiki tribes, points toward possible genetic clustering, limited access to preventive healthcare, and lack of early screening in these populations.

Area -wise Distribution of Hemoglobinopathies

In the present study we received patients from 21 mandals of ASR district with uneven distribution of hemoglobinopathy cases, with some mandals demonstrating a disproportionately high burden which included Koyyuru with 150 cases, Chinthapalli with 86 cases, Arakuvally with 81 cases, Pedabayalu with 75 cases, G.K. Veedhi with 73 cases. These five mandals together accounted for 465 cases, comprising over 60% of the total affected population.

These areas are characterized by a high concentration of tribal communities, limited access to healthcare infrastructure, and possible prevalence of consanguinity, which may contribute to the high rates of hemoglobin disorders.

Munchingputtu, G. Madugula, Dumbriguda, Hukumpeta, Paderu mandals showed a moderate prevalence and may require semi-targeted screening and counseling programs. The remaining Low-Burden mandals (e.g., Addathegala, Yetapaka, Rajavommangi, Y. Ramavaram, Devipatnam, and Maredumilli) each contributed fewer than 20 cases.

 The low numbers may reflect lower population density, under-screening, limited access to healthcare infrastructure or due to limited number of patients attending the outpatient clinics from these areas.

Hemoglobinopathies, particularly sickle cell disease (SCD) and thalassemia, pose a significant health burden on tribal populations in India, where they are more prevalent than in non-tribal communities. The prevalence of sickle cell carriers among different tribal groups varies from 1 to 40 per cent (8). This increased prevalence is linked to factors like consanguinity and cultural practices within tribal communities, making them more susceptible to inheriting these genetic blood disorders (9).

The gender distribution in the present HPLC-based hemoglobinopathy study (65.8% female vs. 34.2% male) is consistent with findings across both North and South India. Most studies reporting a higher proportion of females attribute this to mainly Antenatal care (ANC)-based screening, Premarital and reproductive-age screening programs, where women (especially in maternal care contexts) are more likely to be tested.

Notably, all comparative studies(10-13)  (including both large-scale and small hospital-based samples) show female predominance ranging from 60% to 68%, supporting the observation that this trend is common and likely due to sampling strategy rather than actual prevalence differences in hemoglobinopathies.

Table: Comparison study of Gender distribution in Tribal Populations in different studies

The Present Study reveals a striking burden of sickle-related disorders, including S trait (57.8%), S-disease (8.5%), and compound S β-thalassemia (20.2%), together accounting for ~86%. This is far higher than any hospital-based figures, reflecting tribal endemicity. Only ~12% had normal hemoglobin patterns in tribal screening—compared to 40–66% in hospital-based studies highlighting targeted recruitment of at-risk individuals in tribal surveys (13-15). Silvestroni and Bianco were the first to describe the compound heterozygosity (βs/βthal) for the sickle gene and a β-thalassemia gene in 1944(16). Bone fide compound heterozygosity, especially S β-thalassemia, is far more prevalent in tribal samples (20%) than in hospital-based studies (2–14.5%) indicating endogamy and genetic clustering (13-15).

Hemoglobin S with β-thalassemia (HbS/β-thalassemia) requires genetic testing for further stratification, as HPLC patterns alone cannot reliably distinguish between HbS/β⁰-thalassemia, HbS/β⁺-thalassemia, and HbS/HPFH, due to overlapping retention times and variable hemoglobin expression profiles [17–19] .

Table: Comparison study of hemoglobin spectrum on HPLC in different studies

Similarly, Hb E + β-thalassemia occurrences vary, being highest (4%) in Ravi Shankar’s hospital cohort ^(14).While β‑thal trait is relatively rare in tribal (1.3%), it's more common in hospital settings (5‑11%)^(13-15), and severe β-thalassemia major appears notably higher (7%) in Ravi Shankar's study⁽¹⁴⁾.

Table: Comparison study of Community-wise Hemoglobinopathy Distribution in Tribal Populations

The present study had concordance with Atla B et al.⁽²³⁾ study on community prevalence which is correlating with the population trends in this agency area.

This comprehensive study evaluated the prevalence and distribution of hemoglobinopathies among the tribal population attending a tertiary care hospital in Paderu, Alluri Sitarama Raju District, Andhra Pradesh, utilizing High-Performance Liquid Chromatography (HPLC) for accurate diagnosis.

The most common hemoglobinopathy was Sickle Cell Trait (SCT) (65.5%), followed by Sickle + β-Thalassemia (22.9%) and Sickle Cell Disease (SCA) (9.6%).

Community-wise distribution showed that Bagatha and Valmiki tribes accounted for the largest number of cases, followed by Konda Dora and Kammara, highlighting the need to focus screening efforts on these high-burden tribal groups. These findings are supported and contrasted by existing literature from Andhra Pradesh, Odisha, Telangana, and Central India, which showed variability in affected communities like Gond, Koya Dora, and Lambada.

Overall, this study adds novel insights into the geographically and ethnically clustered burden of hemoglobinopathies in Eastern Ghats tribal populations. It underscores the urgent need for region-specific genetic screening, counseling programs, and early therapeutic interventions, especially in underserved tribal belts. Future research should focus on multi-centric studies with long-term follow-up to form public health strategies and policy planning in tribal healthcare.

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