Tay-Sachs disease is a genetic disorder due to the deficiency of enzyme Hexosaminidase A. The disease occurs when harmful quantities of cell membrane components known as gangliosides accumulate in the brain&;s nerve cells, eventually leading to the premature death of the cells. symptoms: mental retardation, blindness, muscular weakness.Sickle cell anemia is an autosomal genetic disorder. Mutations in the globin genes that alter the protein composition, mutations leading to qualitative alterations in hemoglobin, the missense mutation in the b-globin gene that causes sickle cell anemia.T he mutation causing sickle cell anemia is a single nucleotide substitution (A to T) in the codon for amino acid 6. The change conves a glutamic acid codon (GAG) to a valine codon (GTG). The form of hemoglobin in persons with sickle cell anemia is referred to as HbS.Cystic fibrosis (CF) is an inherited disease that affects the secretory glands, including the mucus and sweat glands. Cystic fibrosis mostly affects the lungs, pancreas, liver, intestines, sinuses, and sex organs. CF is due to a mutation in the CF gene on chromosome 7. The CF gene encodes a protein known as the cystic fibrosis transmembrane regulator (CFTR). The abnormal CFTR protein in patients with CF leads to disruption of chloride channels on the cells.Wilson&;s disease is a genetic disorder in which copper builds up in the body. Wilson&;s disease is an autosomal recessive condition due to a mutation in the Wilson disease protein (ATP7B) gene. For a person to be affected they must inherit an affected copy of the gene from each parent.Ref: Harper&;s biochemistry, 30th edition, page: 251