<prompt> Sickle cell disease is due toPoint mutationFrom shift mutationNucleotide receptor blockageNon sequence mutation  <response>: Point mutation 628-R 227-426-Basicpathology 8thSickle cell disease is an important hereditary hemoglobinopathy, a type of disease characterized by production of defective hemoglobins.Sickle cell disease is caused by a point mutation at the sixth position of the b-globin chain leading to the substitution of a valine residue for a glutamic acid residue.Sickle syndromes occurs in 3 different forms 394-HM 5th1. As heterozygous state for HbS: Sickle cell trait AS2. As homozygous state for HbS: Sickle cell anaemia SS3. As double heterozygous states eg. Sickle p-thalassaemia Sickle-C-disease, sickle-D disease SDFrame-shift mutation - occurs when there is insertion or deletion of one or two base pairs in the DNA sequence eg. Cystic fibrosis 