Its another case of inheritance of traits on autosomal chromosome..Sickle-cell disease, or sickle-cell anaemia is a life-long blood disorder .Characterized by red blood cells that assume an abnormal, rigid, sickle shape.
Sickling decreases the cells' flexibility and results in a risk of various complications.
The sickling occurs because of a mutation in the hemoglobin gene.
Sickle cell disease results when a person inherits an allele for sickle-cell hemoglobin from each of his or her parents.
This inheritance pattern means that the person is homozygous for sickle-cell hemoglobin and that his or her body does not produce any normal hemoglobin, but only sickle cell hemoglobin.
Geneticists show the inheritance pattern of sickle-cell disease by using symbols to represent the allele for normal hemoglobin (Hb A) and the allele for sickle-cell hemoglobin (HB S). A person with normal hemoglobin has inherited one allele for normal hemoglobin from each parent and so has the genotype Hb A/Hb A. In contrast, a person who has sickle disease has inherited one sickle-cell allele from each parent and has the genotype Hb S/Hb S.
But what about a person who inherits an allele for normal hemoglobin from one parent and an allele for sickle-cell hemoglobin from the other parent? This person has the genotype Hb A/Hb S, and is said to have sickle-cell trait.
Although some of the hemoglobin in this person's body is sickle-cell hemoglobin, the rest of the hemoglobin is normal, and the person usually exhibits no symptoms of the disease.
..The genetic Diagram is similar to albinism...just change the KEY..
No comments:
Post a Comment