Characteristics of gene mutation in Chinese patients with hereditary hemochromatosis

Objective To investigate the characteristics of gene mutation in Chinese patients with hereditary hemochromatosis( HH).Methods A total of 9 patients with HH who visited Beijing Friendship Hospital,Capital Medical University from January 2013 to December2015 were enrolled. The genomic DNA was extracted,and PCR amplification and Sanger sequencing were performed for all the exons of four genotypes of HH,i. e.,HFE( type Ⅰ),HJV( type ⅡA),HAMP( type ⅡB),TFR2( type Ⅲ),and SLC40A1( type Ⅳ) to analyze gene mutations. A total of 50 healthy subjects were enrolled as control group to analyze the prevalence of identified gene mutations in a healthy population. Results Of all patients,2 had H63 D mutation of HFE gene in type Ⅰ HH,1 had E3 D mutation of HJV gene in typeⅡA HH,2 had I238 M mutation of TFR2 gene in type Ⅲ HH,and 1 had IVS 3 + 10 del GTT splice mutation of SLC40A1 gene in type ⅣHH. No patients had C282 Y mutation of HFE gene in type Ⅰ HH which was commonly seen in European and American populations. Five patients had no missense mutation or splice mutation. In addition,it was found in a family that a HH patient had E3 D mutation of HJV gene,H63 D mutation of HFE gene,and I238 M mutation of TFR2 gene,but the healthy brother and sister carrying two of these mutations did not had the phenotype of HH. Conclusion HH gene mutations vary significantly across patients of different races,and non- HFE- HH is dominant in the Chinese population. There may be HH genes which are different from known genes,and further investigation is needed.