Mutations in hepcidin and any genes that regulate the biology of hepcidin, including hemochromatosis genes (HFE), Hemojuvelin (HJV), transferring receptor 2 (TFR2) and FPN, result in hemochromatosis.
Here, we report a heterozygous genotype at two mutation sites in hemojuvelin (HJV) present in two brothers with middle-age-onset hemochromatosis in a Chinese family.
To date, four types of hemochromatosis have been identified: HFE-related or type1 hemochromatosis, the most frequent form in Caucasians, and four rare types, named type 2 (A and B) hemochromatosis (juvenile hemochromatosis due to hemojuvelin and hepcidin mutation), type 3 hemochromatosis (related to transferrin receptor 2 mutation), and type 4 (A and B) hemochromatosis (ferroportin disease).
To screen exon-by-exon DNA sequences of HFE, HJV, HAMP, TFR2 and SLC40A1 genes to characterize the molecular basis of HH in a sample of the Brazilian population.
Hepcidin deficiency underlies iron overload in HFE-hemochromatosis as well as in several other genetic iron excess disorders, such as hemojuvelin or hepcidin-related hemochromatosis and transferrin receptor 2-related hemochromatosis.
Mutations in HAMP and HJV genes and their impact on expression of clinical hemochromatosis in a cohort of 100 Spanish patients homozygous for the C282Y mutation of HFE gene.
We conclude that homozygosity for HJVR54X accounts for his severe, early age-of-onset hemochromatosis; his phenotype was probably modified by serial phlebotomy therapy.
We used a standard 96-well microplate with a single PCR condition in an adaptation of the SCAIP (single-condition amplification with internal primer) method to sequence the HFE (hemochromatosis), HAMP (hepcidin antimicrobial peptide), HFE2/HJV [hemochromatosis type 2 (juvenile)], SLC40A1 (ferroportin), and TFR2 (transferrin receptor 2) genes, and the 5' untranslated region of the FTL (ferritin, light polypeptide) gene.
Individuals with pathogenic mutations in HFE, hemojuvelin (HJV) and transferrin receptor 2 (TfR2) have low levels of hepcidin, but little is known about the hepatic expression of these molecules in patients with physiological iron overload or HFE associated Hemochromatosis (HH).
The term hemochromatosis should refer to a unique clinicopathologic subset of iron-overload syndromes that currently includes the disorder related to the C282Y homozygote mutation of the hemochromatosis protein HFE (by far the most common form of hemochromatosis) and the rare disorders more recently attributed to the loss of transferrin receptor 2, HAMP (hepcidin antimicrobial peptide), or hemojuvelin or to certain ferroportin mutations.
The data show that heterozygous mutations of the hemojuvelin gene contribute like those of hepcidin to the phenotypic heterogeneity of hemochromatosis.