Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eight hemochromatosis probands with HFE C282Y homozygosity had frequent, severe, or unusual infections and common variable immunodeficiency (CVID) or immunoglobulin (Ig) G subclass deficiency (IgGSD). Thus, we performed serum Ig isotyping and other characterization of 43 additional unselected probands, 5 human leukocyte antigen (HLA)-identical siblings, and 240 consecutive CVID or IgGSD index patients. C282Y allele frequencies were estimated in 58 CVID or IgGSD index patients without hemochromatosis phenotypes and in 341 controls. HLA-A and -B haplotypes and frequencies were determined in all 51 probands, 186 CVID or IgGSD index patients without hemochromatosis phenotypes, and 751 controls. Thirteen unselected probands (30%) had CVID or IgGSD. Among all 21 hemochromatosis probands with CVID (n = 4) or IgGSD (n = 17), Ig subclass deficiency patterns were IgG(1) (n = 5), IgG(1) and IgG(3) (n = 6), IgG(3) (n = 9), and IgG(1), IgG(3), and IgG(4) (n = 1). IgG(2) or IgA deficiency was not detected; one proband had IgM deficiency. Mean values of total IgG, IgG(1), and IgG(3) were significantly lower in probands with CVID or IgGSD. Mean values of age, transferrin saturation, and ferritin at diagnosis and phlebotomy units required to induce iron depletion were similar in probands with or without CVID or IgGSD; phlebotomy had no apparent effect on IgG levels. C282Y frequencies were similar in CVID or IgGSD index cases without hemochromatosis phenotypes and in controls. There was concordance of Ig and hemochromatosis phenotypes in probands and respective HLA-identical siblings. Eight of 240 CVID or IgGSD index patients had hemochromatosis phenotypes and C282Y homozygosity (3 vs 0.7% and 0.2% controls; P < 0.0001, respectively). The frequency of A*03-B*07 was greater in CVID and IgGSD index cases without hemochromatosis phenotypes than in controls (0.0968 vs 0.0546, respectively; P = 0.0032). HLA-A*03-B*07 was the predominant haplotype in probands grouped by presence or absence of CVID or IgGSD. Some probands in each group were A*03-B*07 homozygotes; group A*03-B*07 frequencies were similar. We conclude that serum IgG abnormalities characteristic of CVID or IgGSD are common in hemochromatosis probands, and that the prevalence of hemochromatosis is increased in CVID and IgGSD index cases. These observations could be explained by the increased frequencies of HLA-A*03-B*07 in C282Y homozygotes and in CVID and IgGSD, and by the common occurrence of putative CVID or IgGSD allele(s) on haplotypes bearing C282Y.
 ...
PMID:Common variable immunodeficiency and IgG subclass deficiency in central Alabama hemochromatosis probands homozygous for HFE C282Y. 1285 Apr 93

Primary iron overload may be relatively common in African Americans, but its cause is incompletely understood. Thus, we evaluated genotype and phenotype characteristics of unselected African American index patients with primary iron overload who reside in central Alabama. All had hepatic iron concentration > or =30 micromol/g dry wt or > or =2.0 g of iron mobilized by phlebotomy to achieve iron depletion. Genotype analyses were performed in African American control subjects from the same region. There were 23 patients (19 men, 4 women); mean age at diagnosis was 52 +/- 12 years (1 SD) (range 32-69 years). Nine (39.1%) reported that they consumed > or =45 g of ethanol daily; five had chronic hepatitis C. Eight had some form of hemoglobinopathy or thalassemia. Mean serum transferrin saturation was 56 +/- 28% (range 15-100%). The geometric mean serum ferritin at diagnosis was 1076 ng/mL [95% confidence interval 297-3473 ng/mL]. Increased stainable liver iron was observed in hepatocytes only in 4 patients, in macrophages only in 8 patients, and in hepatocytes and macrophages in 8 patients. The mean quantity of iron mobilized by phlebotomy (corrected for iron absorbed during treatment) was 5.3 +/- 2.0 g (range 4.0-8.4 g). Iron removed by phlebotomy was greater in patients with hemoglobinopathy or thalassemia than in those without these forms of anemia (6.6 +/- 1.3 g vs 3.9 +/- 1.6 g, respectively; P = 0.0144). Daily consumption of > or =45 g of ethanol or chronic hepatitis C was not associated with an increased or decreased amount of phlebotomy-mobilized iron, on the average. The percentage of index patients positive for HFE C282Y was greater than that of controls (P = 0.0058). The respective percentages of phenotype positivity for HFE H63D, D6S105(8), and HLA-A*03 were similar in patients and controls. HFE S65C, I105T, and G93R were not detected in index or control subjects. Two of 13 patients were heterozygous for the ferroportin allele nt 744 G-->T (Q248H), although the phenotype frequency of this allele was similar in patients and 39 controls. Synonymous ferroportin alleles were also detected in some patients. The ceruloplasmin mutation nt 1099C-->T (exon 6; Arg367Cys) was detected in 1 of 2 patients tested. Abnormal alleles of beta-2 microglobulin, Nramp2, TFR2, hepcidin, or IRP2 alleles were not detected in either of the 2 patients so tested. We conclude that primary iron overload in African Americans is not the result of the mutation of a single gene. HFE C282Y, ferroportin 744 G-->T, and common forms of heritable anemia appear to account for increased iron absorption or retention in some patients.
 ...
PMID:Genotypic and phenotypic heterogeneity of African Americans with primary iron overload. 1463 44

Before the discovery of HFE, reports suggested that hemochromatosis patients with the ancestral haplotype (or some element thereof) have more severe iron overload than those without the haplotype. We performed univariate and multivariate analyses of the relationships of human leukocyte antigen (HLA)-A*03 and HLA haplotype A*03-B*07 to iron measures (serum iron concentration, transferrin saturation, and serum ferritin concentration at diagnosis and units of phlebotomy to achieve iron depletion) in hemochromatosis probands homozygous for HFE C282Y diagnosed in medical care. Iron overload was defined by demonstration of hepatic iron index of > or =1.9 or removal of > or =2.0 g Fe by therapeutic phlebotomy. We tabulated the phenotype frequencies of HLA-A*03 and the frequencies of common HLA haplotypes A*01-B*08, A*02-B*44, A*03-B*07, and A*03-B*14 in three groups of white adults: (1) 141 hemochromatosis probands with C282Y homozygosity; (2) 195 index cases with IgG subclass deficiency (IgGSD) or common variable immunodeficiency (CVID), disorders typically linked to Ch6p, and (3) 750 control subjects. Among probands, 86 men and 42 women had iron overload. Frequencies of HLA-A and -B alleles in probands did not depart significantly from Hardy-Weinberg equilibrium. The phenotype frequency of A*03 did not differ significantly between men and women in the each of the respective three groups. The frequency of haplotype A*03-B*07 was greater in men than women with hemochromatosis (0.3081 vs. 0.1455; P = 0.0019). The frequency of A*03-B*014 was significantly greater in women than men with hemochromatosis (0.1182 vs. 0.0407, respectively; P = 0.0134). Mean values of most iron measures were not affected by numbers of copies of A*03 or by presence of A*03-B*07 in either men or women in univariate analysis. ANOVA models of sex, age at diagnosis, and all HLA alleles and haplotypes in probands were used to determine effects of these variables on iron measures. ANOVA models revealed that (1) there were no significant predictors for serum iron concentration; (2) B*14 is associated with higher transferrin saturation in women and lower transferrin saturation in men; (3) A*01-B*08 is associated with a trend of higher serum ferritin levels; and (4) A*03-B*14 is associated with exaggeration of the age-associated upward trend in units of phlebotomy to achieve iron depletion. In hemochromatosis probands with HFE C282Y homozygosity, we conclude that (1) disparate frequencies of HLA haplotypes A*03-B*07 and A*03-B*14 occur in men and women and (2) HLA-A*03 and HLA-A*03-B*07 are not independent variables associated with iron overload severity.
 ...
PMID:HLA haplotype A*03-B*07 in hemochromatosis probands with HFE C282Y homozygosity: frequency disparity in men and women and lack of association with severity of iron overload. 1560 98