Location
11p15.4 – chromosome 11, on short arm of chromosome, region 1, band 5, sub-band 4
Gene/locus
HBB – haemoglobin subunit beta
HTML reference
Stumpf, A.M. (2013). Sickle cell disease Available form: http://www.omim.org/entry/603903?search=Sickle%20Cell%20Disease&highlight=cell%20sickle%20disease
Frequency
More than 230 000 children with sickle cell disease are born in Africa every year, which makes about 80% of the global total. In Europe estimated number of affected births is 1300. In England estimated number of people with sickle cell trait is 250,000. This disease is the most common the areas where there is high probability of malaria disease.
Inheritance pattern
Sickle cell disease is inherited …show more content…
Sickle cell trait is protective against malaria infection. Haemoglobin contains haem which is a porphyrin containing ferrous iron. Normally haem is not found in free form in blood. But for people with sickle cell disease trait haem is present in a free form at high levels in blood. This free haem is toxic to malaria parasite. That is the reason why people with sickle cell disease are less likely to develop malaria. This advantage explains why sickle cell disease did not disappear form areas in the world where malaria is common.
Cellular location
Cytosol of red blood cells
Tissue expression
Primary blood tissue and bones but all body tissue can be affected. Most commonly affected tissues are: brain, kidneys, liver, lungs and heart.
Mechanistic consequence
Haemoglobin S has a lower oxygen affinity that haemoglobin A normally found in healthy adults. As a result hemoglobin has different physical properties such as polymerization, contrasting solubility and molecular stability. This leads to the erythrocytes becoming sickle-shaped and not able to bind oxygen efficiently. Sickled red blood cells can clog small blood vessels and capillaries, resulting in a lack of oxygen for the tissues. That can cause chronic pain, tissue infections and damage of organs.
Protein …show more content…
If disease is detected early, patients have great chance to live up to middle age. The most common reasons of death are bacterial infections. Mortality is high, especially in the early childhood years.
References
Rees, D.C., Williams, T.N., Gladwin, M.T. (2010). Sickle-cell disease. The Lancet. 376 (9757), 2018-2031
Gravitz, L. and Pincock, S. (2014). Sickle-cell disease. Nature. 515 (7526), S1
Stumpf, A.M. (2013). Sickle cell disease Available form: http://www.omim.org/entry/603903?search=Sickle%20Cell%20Disease&highlight=cell%20sickle%20disease
Uniprot (2015). Hemoglobin subunit beta. Available from: http://www.uniprot.org/uniprot/P68871
Maakaron, J.E. (2015). Sickle cell anaemia. Available from: http://emedicine.medscape.com/article/205926-overview