During genetic testing, one parent is found to have a chromosomal abnormality without any physical or mental disability; however, the offspring has inherited physical and/or mental disability

Question

During patient education, the nurse explains that the type of individual who can have a chromosomal abnormality without any disability but can cause his offspring to receive chromosomal alterations and disability is the parent with: 1. Dominant-gene structural chromosomal inversions.
2. Mosaicism.
3. Dominant-gene structural chromosomal balanced translocations.
4. Dominant-gene structural chromosomal deletions.

Answer 1

3
Rationale 1: Individuals with other dominant-gene chromosomal alterations will all manifest some physical or mental abnormality themselves.
Rationale 2: The individual with mosaicism will display varying degrees of disability, depending on the percentage of cells that are affected. The clinical consequences of inversion depend on how much genetic material was rearranged.
Rationale 3: The parent with balanced translocations can show no signs of physical or mental disability but cause offspring to receive chromosomal alterations, such as trisomy 21.
Rationale 4: A genetic deletion, such as is seen with cri du chat syndrome, results from a deletion on chromosome 5. This would be obvious in the parent as well as the child.
Global Rationale: