Absence of hemochromatosis associated Cys282Tyr HFE gene mutation and low frequency of hemochromatosis phenotype in nonalcoholic chronic liver disease patients in India

Abstract

Background and aim: Hereditary hemochromatosis (HHC) is an autosomal recessive disorder causing primary iron overload syndrome and chronic liver disease (CLD). This genetic disease is commonly associated with C282Y mutation of the HFE gene, commonly seen in the Northern European population. Minor reports on HHC are available from Asia, however, so far no genetic study is available from India. We prospectively studied the prevalence of C282Y mutation in CLD patients and healthy subjects in a tertiary care referral center in India.

Methods: A total of 249 consecutive biopsy proven CLD (HBV = 112, HCV = 72, cryptogenic = 65) patients and 134 age matched healthy controls were included. Cases of secondary iron overload, pregnancy, chronic alcoholism, age < 30 years and hepatocellular carcinoma (HCC) were excluded. A transferrin saturation index (TSI) of >60% was suggestive of a phenotypic presentation of HHC. C282Y mutation was studied by restriction fragment length polymorphism (RFLP) using genomic DNA. The 387 bp fragment obtained after polymerase chain reaction was digested with 10 units of endonuclease Rsa1. The mutation was detected by creation of an additional restriction site, giving rise to fragments of 247 111 and 29 bp.

Results: While the mean TSI was comparable, serum ferritin was significantly higher in CLD patients compared to controls (38 +/- 16%vs 28 +/- 13%; p = not significant (NS), and 125 +/- 18 vs 42 +/- 25 ng/mL; p < 0.001). A TSI of >60% was detected in 24 (9.64%) patients. Only one restriction site was found for endonuclease Rsa1, giving rise to two fragments of 247 and 140 bp, suggesting absence of C282Y mutation in the HFE gene in all patients.

Conclusions: Almost 10% of nonalcoholic CLD patients in India have iron overload, but this is independent of C282Y mutation of the HFE gene. Large population based studies are recommended to investigate the prevalence of this rare disorder in India.