Sickle cell disease Essay Example | Topics and Well Written Essays - 500 words

Sickle cell disease - Essay Example The chance of one of her parents being a carrier is 1 in 2 (1/2). Assuming that one of her parents had normal copies of CFTR and the other parent was a carrier, the chances of their siblings being a carrier is 1 in 2 (1/2). So the chances of my friend being a carrier is x , i.e , one out of four. Assuming that both my friend and her fianc are carriers, the chances of their baby having the disease are 1 in 4. Therefore, the overall chance of their baby having cystic fibrosis is x x . 1/32, one in a 32. Sickle cell disease: Sickle cell disease is a genetic disorder caused by mutations of the -globin gene. There is a mutation of one single nucleotide from A to T, which results in a glutamic acid being replaced by valine at position 6 of the -globin gene. GAG, a codon, which codes for glutamic acid is changed to GUG resulting in replacement with valine (Pauling et al., 1949). In several forms of this disease, the red blood cells (RBC's) change their shape (Herrick, JB., 1910), upon deoxygenation caused by polymerization of abnormal sickle hemoglobin (Hanh and Gillespie, 1927). This results in the damage of the RBC's and can lead to these cells getting stuck in capillaries. The downstream tissues that are supplied by these capillaries are deprived of oxygen causing ischemia, leading to organ damage, as in stroke.