Miss X's Family Pedigree Discussion

1. List the individuals in the pedigree chart who are carriers for beta-thalassemia.
The carriers for beta-thalassemia in the pedigree are her grandfather, grandmother, mother, father and herself.

2. List the individuals in the chart who are indicated as heterozygous for the β-globin gene.
Miss X's grandfather, grandmother, mother, and father.

3. Explain why only Miss X's has the disease.
She is the only one with the disease since thalassemia is an autosomal recessive disease, which means that to have the disease her mother and father have to be carriers. Her mother did not have the disease since she had 25% of not having it, 50% of being a carrier and 25% of being normal.

4. Speculate on why a mutation in the non-coding, intron region of the β-globin gene could produce a defective β-globin protein.
If there is a mutation in the B-globin gene it means that the nucleotides are not in the correct order to form the necessary proteins that the B-globin gene must produce. For example if a intron is supposed to be ATTGC and there is a substitution in the C for a A then the intron would be ATTGA. So the code is changed and when a tRNA reads the sequence it will pick the wrong amino acid and thus another protein or no protein will be created.