Saturday, March 8, 2014

Sickle-cell (Drepanocytes)

Sickle-cell (Drepanocytes)



Background Information of Sickle Cells (Drepanocytes) clumps
Sickle-cell (drepanocytosis) anaemia (SCA) is a hereditary blood disorder, characterized by RBCs that assume an abnormal, rigid, sickle shape. Sickle cell anemia is a form of sickle-cell disease in which there is homozygosity for the mutation that causes HbS which deteriorates the cells' flexibility and results in a risk of various life-threatening complications. Life expectancy is expected to be shortened but improvements and advances in science, patients can live into their 70s or beyond. Individuals with one copy of the defunct gene display both normal and abnormal haemoglobin. This is an example of codominance.
Sickle-cell disease occurs more commonly among people whose ancestors lived in tropical and sub-tropical sub-saharan regions where malaria is or was common. Where malaria is common, carrying a single sickle-cell allele (sickle cell trait) confers a selective advantage. Specifically, humans with one of the two alleles of sickle-cell disease show less severe symptoms when infected with malaria.

n HbSS, the FBC will reveal haemoglobin levels in the range of 6–8 g/dL with high reticulocyte count (as the bone marrow compensates for the destruction of sickle cells by producing more RBCs). In other forms of sickle-cell disease, Hb levels tend to be higher. A PBF may show features of hyposplenism (target cells and Howell-Jolly bodies).

Cellular Description

Red cells varying in shape but mostly look like a sickle with sharp-pointed edges.

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