Polyarticular osteoarthritis--two major phenotypes hypothesized.
ABSTRACT Osteoarthritis is the commonest form of arthritis, at least amongst Caucasians and is frequently polyarticular. Genetic factors are now considered pivotal in the aetiopathogenesis of polyarticular osteoarthritis (POA). This document proposes a nexus between the gene most commonly mutated amongst Caucasian peoples, notably the HFE gene and an appreciable subset of POA patients who have a clinically recognisable OA phenotype. It is hypothesised that there are at least 2 major POA phenotypes each of which is associated with discrete genotypes. Type 1 POA characterized by Heberden's or Bouchard's nodes with prominent DIP, PIP, knee joint (medial compartment) and Great toe MTP joint involvement corresponds to the putative nodal generalized form of OA or NGOA (proposed Type 1 POA phenotype). As yet no genetic marker has been defined for this POA subset. The second is a hitherto less well recognized phenotype characterized by involvement of the index and/or middle finger metacarpophalangeal (MCP2,3) joints and the elbows, ankles and possibly the intertarsal and tarsometatarsal joints. The hip and knee joints may sometimes also be involved. This different joint distribution corresponds closely to the pattern observed in the arthropathy that often accompanies hereditary haemochromatosis. It is predicted that mutations in the HFE gene will associate strongly with the proposed Type 2 POA phenotype and serve as a genetic marker for this clinically recognisable subset.
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ABSTRACT: Excess iron stores have been postulated to enhance the risk of ischaemic heart disease. This study aims to determine whether the two major mutations of the haemochromatosis (HFE) gene (C282Y and H63D) are associated with ischaemic heart disease (IHD) or myocardial infarction (MI). Cross sectional case-control study. The geographical area studied by the MONICA (monitoring trends and determinants in cardiovascular disease) heart attack register for North Glasgow in Scotland, UK. 1009 control subjects chosen at random from general practitioner registers were studied. Additionally, 924 subjects who had survived a first MI sustained between 1985 and 1992 were identified from the MONICA register. C282Y and H63D mutations, previous MI, and presence or absence of IHD. Mutant gene prevalences in the whole control population were as follows: C282Y: homozygote 0.9%, heterozygote 17.7%; H63D: homozygote 2.1%, heterozygote 25.5%; and compound heterozygote: 2.4%. Analysis by chi(2) test and logistic regression analysis did not identify any significant difference in genotype prevalence between normal control, IHD control, and MI survivor groups. The C282Y homozygote and heterozygote prevalences are among the highest reported worldwide. No association between IHD or MI and HFE genotype was identified. However, these results need to be interpreted in the light of the cross sectional case-control nature of the study.Heart (British Cardiac Society) 10/2003; 89(9):1023-6. · 5.01 Impact Factor
- Blood 05/2005; 105(8):3381-2. · 9.06 Impact Factor
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ABSTRACT: Hereditary haemochromatosis (HH), which affects some 1 in 400 and has an estimated carrier frequency of 1 in 10 individuals of Northern European descent, results in multi-organ dysfunction caused by increased iron deposition, and is treatable if detected early. Using linkage-disequilibrium and full haplotype analysis, we have identified a 250-kilobase region more than 3 megabases telomeric of the major histocompatibility complex (MHC) that is identical-by-descent in 85% of patient chromosomes. Within this region, we have identified a gene related to the MHC class I family, termed HLA-H, containing two missense alterations. One of these is predicted to inactivate this class of proteins and was found homozygous in 83% of 178 patients. A role of this gene in haemochromatosis is supported by the frequency and nature of the major mutation and prior studies implicating MHC class I-like proteins in iron metabolism.Nature Genetics 09/1996; 13(4):399-408. · 35.21 Impact Factor