Background: This study has investigated the association between haptoglobin (Hp) polymorphism and the occurrence of chronic renal failure (CRF) in Jordanians.
Methods: Blood specimens were collected from 159 patients with CRF resulting from various predisposing conditions and from 200 healthy unrelated controls. Hp phenotyping was conducted using polyacrylamide gel electrophoresis.
Results: The Hp 2-2 phenotype was over-represented in CRF patients in general (0.547), patients with hypertension (0.622) and patients with diabetes mellitus (0.633). The Hp 2-1 phenotype was over-represented in patients with chronic glomerulonephritis (0.549) and patients with reflux nephropathy (0.445). In patients with polycystic kidney disease (PKD), only Hp 2-1 and Hp 2-2 were detected, occurring at a frequency of 0.214 and 0.786, respectively. The frequency of Hp 2 allele in PKD patients was 0.893 compared with 0.706 in the control group. Hp-type distribution was in agreement with the expectations of a population in Hardy-Weinberg equilibrium in all groups except for the hypertensive patients.
Conclusions: Haptoglobin homozygosity seems to represent a possible risk factor for CRF in hypertensive, diabetic and PKD patients; Hp heterozygosity may lead to chronic glomerulonephritis.