Prevalence of Idiopathic Erythrocytosis in Indian Population
Direct Answer
There is no published epidemiological data on the prevalence of idiopathic erythrocytosis specifically in the Indian population. The available evidence provides prevalence estimates from other populations but contains no India-specific data for this condition.
Global Prevalence Context
- The frequency of idiopathic erythrocytosis (IE) has been estimated at approximately 1.1 per 1,000 subjects in studied populations, which is notably higher than the prevalence observed in polycythemia vera 1
- This global estimate comes primarily from Western populations and may not be generalizable to the Indian subcontinent 1
Why Indian Data is Lacking
The absence of Indian prevalence data for idiopathic erythrocytosis mirrors a broader pattern seen with other rare hematologic conditions:
- Diagnostic infrastructure limitations: Many low- and middle-income countries, including India, face challenges in diagnosing rare hematologic disorders due to limited access to specialized testing 2
- Underdiagnosis: The diagnosis of IE requires exclusion of primary polycythemia vera (including JAK2 V617F and exon 12 mutations), secondary causes of erythrocytosis, and familial erythrocytosis—a diagnostic workup that requires sophisticated molecular testing not universally available 3, 4, 1
- Lack of epidemiologic studies: There is virtually no epidemiologic data from India on related conditions, suggesting systematic gaps in population-based research for rare hematologic disorders 2
Diagnostic Complexity Affecting Case Identification
The diagnosis of IE is particularly challenging and requires:
- Confirmation of absolute erythrocytosis (elevated red blood cell mass) 1, 5
- Exclusion of JAK2 V617F mutation (present in most polycythemia vera cases) 4
- Exclusion of JAK2 exon 12 mutations (found in 27% of patients with low serum erythropoietin levels who lack V617F) 4
- Exclusion of secondary causes (hypoxia, tumors, renal disease) 5
- Exclusion of familial/congenital erythrocytosis (germline mutations in oxygen-sensing pathway genes) 5, 6
This diagnostic complexity means that without access to comprehensive molecular testing, many IE cases in India likely remain undiagnosed or misclassified 2.
Implications for Clinical Practice in India
Given the absence of local data:
- Assume similar prevalence: In the absence of India-specific data, clinicians should assume a prevalence similar to global estimates (approximately 1 per 1,000) until local studies demonstrate otherwise 1
- High index of suspicion needed: The actual number of diagnosed IE cases in India is likely far below the true prevalence due to diagnostic limitations 2
- Recent molecular insights: Approximately 71% of IE cases show no evidence of clonal hematopoiesis, suggesting IE is largely a germline disorder with recurrent variants in JAK/STAT, hypoxia, and iron metabolism pathways 6
Critical Knowledge Gap
Population-based epidemiological studies are urgently needed in India to determine the true prevalence of idiopathic erythrocytosis, as the current absence of data represents a significant gap in understanding the burden of this condition in the world's second-most populous country 2.