SICKEL CELL ANAEMIA

 Sickle Cell Anaemia : Sickle cell anaemia is an autosome linked recessive disease. Here in this disease both male and female can become diseased or both may be carrier depending upon the presence of  infected gene/s .Here in this context we need to know two words homozygous and heterozygous. Homozygous individual are those when two  chromosomes have the infected gene ie. HbS and HbS and in case of Hetrozygous individual their two chromosomes are arranged as HbS and HbN.                                           Here HbS is characterised by sickle condition and HbN is normal. 

Human blood cells are Biconcave disc shape, which maximises the surface area of the cell membrane for oxygen . But in case of sickle cell Anaemia cell take the shape of a Sickle and it become difficult for the blood capillaries to transport those cells. In such condition the person suffers from oxygen tension. Genetically it is a point mutation where a change of single base pair in the gene for beta globin chain that results in the change of amino acid residue glutamate to valine.