Which type of chromosomal rearrangements is most likely to result in lethality?

Question

(a) inversion

(b) duplication

(c) deletion

(d) translocation

Answer 1

Hi Frank,

A deletion would be the most likely to be lethal, especially if the deletion is homozygous, where both sets of a given gene are missing. Compared to the other chromosomal rearrangements listed, a deletion is most likely to result in elimination of genes essential to survival, rather than mere rearrangement, which more often result in survivable diseases.

Heterozygous deletions can also be lethal, partially due to a) genome imbalance or b) when deletion of the dominant allele "unmasks" lethal, recessive alleles.