Classification of human population based on HLA gene polymorphism and the concept of Prakriti in Ayurveda

Correlating phenotypes with genotypes remains the major postgenomic challenge. Attempts to correlate phenotype characteristics associated with ethnicity, geographical divisions, or diseases to genotypes have had limited success. This means that current approaches for identifying phenotypes associated with haplotypes may be inadequate.

We hypothesize that a human phenome based on Ayurveda could provide an appropriate approach. Specifically, there could be a genetic basis for the three major constitutions (Prakriti) described in Ayurveda. The Prakriti classification is based on differences in physical, physiological, and psychologics characteristics and is independent of racial, ethnic, or geographical considerations. It may provide an appropriate means of classifying phenotypes to be considered collectively for genotyping.

As a pilot study to test the hypothesis, we evaluated 76 subjects both for their Prakriti and human leucocyte antigen (HLA) DRB1 types. The genomic DNA was extracted using a standard protocol. Subsequently, HLA DRB1 typing was done by low-resolution polymerase chain reaction sequence specific primers and oligonucleotide probes.

We observed a reasonable correlation between HLA type and Prakriti type. The complete absence of the HLA DRB1*02 allele in the Vata type and of HLA DRB1*13 in the Kapha type are significant, with X2 = 4.715 and p < 0.05. HLA DRB1*10 had higher allele frequency in the Kapha type than in the Pitta and Vata types.

Ayurveda classifies the whole human population in three major constitutions as Vata, Pitta, Kapha and their possible combinations. Their homologous relation to human genetic structure needs to be studied for validation. If validated, our hypothesis would have far reaching implications for pharmacogenomics, modern genetics, human health, and Ayurveda.