Decreased bone resorption

This form of osteopetrosis, also known as autosomal recessive Albers-Schonberg disease or ''marble'' bone disease, is characterized by macro-cephaly, progressive loss of hearing and vision, hepatosplenomegaly, and severe anemia. This form typically presents in early infancy or even during fetal life. Ocular involvement with retinal degeneration occurs in about half by two months of age (Gerritsen et al., 1994). Without bone marrow transplant, the probability of survival to age 6 is only about...

Rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease of unknown etiology that develops in genetically predisposed individuals. It has an estimated prevalence of up to 1 worldwide, although this varies with ethnic and geographic differences. RA is characterized by inflammation in the synovial lining of the joints that can result in pannus formation and destruction of joint cartilage and bone. Genetic predisposition to autoimmune diseases such as RA is complex. The overall heritability of RA is...

Positional cloning of IBD genes

Positional Cloning

Using a positional cloning approach, several investigators were able to detect linkage to IBD on different chromosomes (Cho et al., 1998 Duerr et al., 2000 Hampe et al., 1999a Hampe et al., 1999b Hugot et al., 1996 Rioux et al., 2000 Satsangi et al., 1996b). Nine IBD loci are today accepted as firmly established according to the criteria defined by Kruglyak and Lander (Figure 20.1). Additional loci exhibit suggestive evidence of linkage. Finally, a meta-analysis of the published genome scans...

Acknowledgements

DeLay in preparation of Albagha, O. M., Tasker, P. N., McGuigan, F. E., Reid, D. M. and Ralston, S. H. (2002). Linkage disequilibrium between polymorphisms in the human TNFRSF1B gene and their association with bone mass in perimeno-pausal women. Hum Mol Genet, 11, 2289-95. Allen, R.L., O'Callaghan, C.A., McMichael, A.J. and Bowness, P. (1999). Cutting edge HLA-B27 can form a novel beta 2-microglobulin-free heavy chain homodi-mer structure. J Immunol, 162, 5045-8. Allen,...

Ankylosing spondylitis

Ankylosing spondylitis AS is another inflammatory arthritic disease of unknown etiology that differs in many ways from RA. It belongs to a family of disorders known as spondyloarthritides SpA that have a tendency to occur in individuals with the MHC class I allele, HLA-B27. From 90 to 95 of individuals with AS carry HLA-B27 compared to less than 10 of most healthy populations, making this one of the strongest HLA-disease associations. For interested readers the April, 2004 issue of Current...