The sickle mutation is found on the 11th chromosome. This mutation codes for the substitution of the 6th amino acid on the polypeptide of the hemoglobin. A glumatic acid is substituted for a valine on this 146 amino acid long polypeptide chain. This substitution is what causes the red blood cell to have its sickle shape. What is Sickle Cell Trait and how does it differ from the disease? A person with the Sickle Cell trait is a person who carries one sickle hemoglobin producing gene and a normal hemoglobin gene. Each gene is inherited from a different parent. A person who has the disease carries two alleles that produce abnormal hemoglobin. Normal hemoglobin is called type A. Sickle hemoglobin called S. Sickle cell trait is the presence of hemoglobin AS, and will not cause the disease. Sickle Cell Anemia is the presence of SS and will cause the disease. With both AS and SS, a person can pass the trait or disease to his children. How is it inherited? Sickle Cell Anemia is an autosomal recessive condition. This means that a person must inherit the recessive Sickle Cell Allele from both parents. If the person is heterzygous he is a carrier of Sickle Cell Anemia and does not have the disease. If a person is homozygous for the recessive allele, he unfortunately has the disease. Detection |
