Question

8) A pt. has severe mental retardaction caused by a deletion of a chromosome B. What genetic disorder will the nurse see documented in the hart a. Prader-Willi syndrome c. Cridu chat Syndrome b. Downs do trisomy x qy the nurse is teaching staff about the most common cause of Downs, what is the nurse describing ? - Paternal non disjunction - maternal rondisjunction - Maternal translocations - paternal translocation 10). A couple has 3 offspring: a child w/ an autosomal dominant disease trait and 2 who are normal, the father is affected by the autosomal dominant, the mather does not have the disease gene. What is the recurrence risk of this autosomal dominant disease for their next Child? a. 50% c.25% b. 33% do impossible to determine 1") An aide asks the nurse why people who have neurofibromatosis will will show varying degrees of the disease. which gonetic principle should the nurse expect a. Renetrance C. Dominance b. Expressivity . Reussivemos gene 18) when a pt. asks what causes cystic fibrosis how should the nurse respond? Cystic fibrosis is caused by an a. X-linked dominant c. Autosomal dominant b. x-linked recessive d. Autosomal recessive 13 A child is born w/ blue eyes (bb), the child's mother has blue, father has brown, which of the following represents the father? a. bb c. Bb D. Bbb

Answer 1

8. Cri-du-chat syndrome is occurring due to deletion of the p arm of chromosome 5. The symptoms of the syndrome depend on the absence of the genes in the p arm.

9. Down’s syndrome is trisomy 21. This is due to the failure of 21 st chromosome to get separate during the development of sperm or egg, or it is called Nondisjunction.

The condition can be due to paternal or maternal non disjunction.

10. If father is dominant for autosomal dominant disease -Rr , mother is not having disease gene- rr.

The possibility for the next child genetic composition are Rr, Rr, rr, rr.

This means there is 50% chance for the next child to get the illness.

11. The variations in the presentation of Neurofibromatosis depend on which gene has been involved in the condition. Mutation of chromosome 17 cause uncontrolled growth of cells as in NF 1.

The mutation of chromosome 22 cause lack of suppression of tumors. Also another condition of neurofibromatosis called Schwannomatosis is caused by mutation in another two genes.

12. Cystic fibrosis is not a sex linked disorder, but it is inherited as the person gets mutated genes from both the parents. So it is an autosomal recessive disorder.

13. Child has blue eys – bb

Mother has blue eyes – bb

Father has brown eyes , means it can be BB or Bb

Since the child has bb, the father’s genetic representation is Bb.