Nail Patella Syndrome
1. Explain what must happen in order for Greg and Susan to have a child with O type blood and nail-patella syndrome. Greg needs to pass down his chromosome 9 which carry the alleles, n and i. Susan also has the n and I alleles on chromosome 9. If both these alleles from both parents are passed down, it will create the allele Nnii which produced the blood type O and nail patella syndrome.
2. Determine all possible parental and recombinant gametes produced by Greg and Susan. Greg’s parental gametes are NI^ and ni; Greg’s recombinant gametes are nI^A and Ni Susan’s parental gametes are nI^B and Ni; Susan’s recombinant gametes are NI^B and ni 3. Determine the frequency of each type of gamete.**
From the case study, we see that the dominant nail- patella trait resides on chromosome and is 10 recombination map units from the I gene. Knowing this information you need to divide 10 by 2 which produces 5. This means that the frequency of recombinant gametes is 5%. To find the parental gametes I took 100 and subtracted 10. Making 90 which is then divided by two (for two parental gametes). This produces 45 which means that both Susan and Greg’s frequency of parental gametes are 45%. 4. Determine the probability of Greg and Susan having a child with nail-patella syndrome and O type blood.**
From the four outcomes: NI^AnI^B, ninI^B, NI^ANi, niNi we come to the conclusion that there is only a 25% chance that Greg and Susan will have a child with nail-patella syndrome and O blood type. We know this because niNI is the only outcome that shows a child with both items. 5. Identify one other condition associated with chromosome 9 and give a brief explanation of it. Another condition associated with chromosome 9 is 9q22.3 microdeletion. This disorder causes seizures occasionally, intellectual disability, physical abnormalities, and delayed development, especially a delay in motor skills (sitting, standing, walking) in individuals. In many the people, the delays are temporary improve and improve as one gets older. This disorder is caused from a deletion of a small piece of chromosome, the q22.3 region (containing at least 270 genes). The affected individual can also have an increased chance of developing tumors and cancer.