title: Evidence for the high importance of co-morbid factors in HFE C282Y/H63D patients cared by phlebotomies: results from an observational prospective study.
abstract: Despite type I haemochromatosis (HC) is mainly associated with the HFE C282Y/C282Y genotype, a second genotype -C282Y/H63D- has mostly been described in other patients. Its association with HC, apart from any associated co-morbid factors, remains unclear and complex to interpret for physicians. This study assesses the weight of this genotype and the role of co-morbid factors in the occurrence of iron overload. This prospective study included the C282Y/C282Y (n = 172) and C282Y/H63D (n = 58) patients enrolled in a phlebotomy program between 2004 and 2007 in a blood centre of western Brittany (Brest, France), where HC is frequent. We compared prevalence of these two genotypes, as well as patients' profile regarding degree of iron overload and prevalence of co-morbid factors. First, we confirmed the obvious deficit of C282Y/H63D compound heterozygotes among patients cared by phlebotomies. This genotype was 3.0 times less frequent than the C282Y/C282Y genotype among those patients (18.9% vs. 56.0%) whereas it was 4.9 times more frequent in the general population (4.3% vs. 0.9%; p<0.0001). Despite a similar level of hyperferritinaemia, the C282Y/H63D patients who came to medical attention had a milder plasma iron overload, reflected by a lower transferrin saturation median (52.0% vs. 84.0%; p<0.0001). They also exhibited more frequently co-morbid factors, as heavy drinking (26.0% vs. 13.9%; p = 0.0454), overweight (66.7% vs. 39.4%; p = 0.0005) or both (21.3% vs. 2.6%; p<0.0001). Ultimately, they required a lower amount of iron removed to reach depletion (2.1 vs. 3.4 g; p<0.0001), clearly reflecting their lower tissue iron. This study confirms that H63D is a discrete genetic susceptibility factor whose expression is most visible in association with other co-factors. It highlights the importance of searching for co-morbidities in these diagnostic situations and of providing lifestyle and dietary advice.
authors: Inserm, UMR 1078, Brest, France ; Université de Bretagne Occidentale, Brest, France ; Etablissement Français du Sang - Bretagne, Brest, France ; CHRU Brest, Hôpital Morvan, Laboratoire d'hygiène et de santé publique, Brest, France.
authors: Philippe
authors: P
authors: Saliou
authors: Gérald
authors: G
authors: Le Gac
authors: Anne-Yvonne
authors: AY
authors: Mercier
authors: Brigitte
authors: B
authors: Chanu
authors: Paul
authors: P
authors: Guéguen
authors: Marie-Christine
authors: MC
authors: Mérour
authors: Isabelle
authors: I
authors: Gourlaouen
authors: Sandrine
authors: S
authors: Autret
authors: Cédric
authors: C
authors: Le Maréchal
authors: Karen
authors: K
authors: Rouault
authors: Jean-Baptiste
authors: JB
authors: Nousbaum
authors: Claude
authors: C
authors: Férec
authors: Virginie
authors: V
authors: Scotet
mesh_terms: D000437:Alcoholism / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D005838:Genotype; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D019190:Iron Overload / Q000453:epidemiology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D050177:Overweight / Q000453:epidemiology* / Q000235:genetics* / Q000628:therapy; D018962:Phlebotomy; D011110:Polymorphism, Genetic; D011446:Prospective Studies
chemical_list: C103673:HFE protein, human; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins