Age group-associated variations in the pattern of Hp type distribution in Jordanians

The relationship between haptoglobin (Hp) type and life expectancy was investigated by determining the pattern of Hp type distribution in 790 unrelated Jordanians divided into four age groups: A (1-19 years), B (20-39 years), C (40-59 years) and D (60-85 years). While the frequency of Hp 2-2 gradually decreased from 0.576 in A to 0.393 in D, the frequency of Hp 2-1 gradually increased from 0.348 in A to 0.526 in D. Hp2 allele decreased from 0.750 in A to 0.656 in D while that of Hpl allele increased from 0.250 in A to 0.344 in D. Hp type distribution in A, B and D age groups was in agreement with the Hardy-Weinberg equilibrium (HWE). These findings demonstrate that the pattern of Hp polymorphism varies in different age groups, indicating that life expectancy might be Hp phenotype-associated. Additionally, the results suggest that Hp 2-2 phenotype might be an age-associated risk factor.