Below are Genetic causes of Sickle cell disease •MUTATION: sickle cell gene mutation probably arose spontaneously in different geographic areas, as suggested by restriction endonuclease analysis. These variants are known as Cameroon, Senegal, Benin Republic, Bantu and Saudi- Asian. Their clinical importance springs from the fact that some of them are associated with higher HBF level, e.g; Senegal and Saudi-Asian variants, and tend to have milder disease. •HETEROZYGOUS: in people heterozygous for Hgbs (carriers of sickling Haemoglobin), the polymerization problems are minor, be because the normal allele is able to produce over 50% of the haemoglobin. HOMOZYGOUS: in people homozygous for Hgbs, the presence of long chain polymers of Hbs distort the shape of the red blood cell from a smooth doughnut-like shape to ragged and full of spikes, making it fragile and susceptible to......continue >>> www.rowlandokonko.com/2016/02/Biology- Sickle-cell-anamia-genetics-diseases.html?m=0