Explanation

Both sickle cell anaemia and Huntington’s chorea are congenital genetic disorders. Sickle cell anaemia was first reported by James Herrick (1904). In this disease, the patient’s haemoglobin level reduced to half of the normal and the RBCs becomessickle shaped. A single mutation in a gene can cause sickle cell anaemia. Huntington’s chorea is caused by autosomal mutation, which is dominant. The gene is present on 4-chromosome numbers.