Question

Autosomal Dominant Compelling Helioopthalmic Outburst (ACHOO) Syndrome is characterized by uncontrollable sneezing in response to the sudden exposure to bright light, typically intense sunlight. ACHOO syndrome is inherited in an autosomal dominant manner. If a heterozygous father has children with a recessive mother predict the outcome of their offspring. Using the allele (A) for dominant and (a) for recessive, identify the following using complete sentences:

Father genotype (1 point)
Mother genotype (1 point)
Possible offspring genotypes (1 point)
Possible offspring phenotypes (1 point)
Possible offspring percentage breakdown (1 point)

Answer 1

The father’s genotype would be Aa. As the mother is recessive, her genotype would be aa.

Below I have attached a Punnett square I made for the genotypes of the offspring. The possible phenotypes could be sneezing uncontrollably as a result to light exposure and also wincing / squinting at the sight of bright light. The percentage that the offspring would have ACHOO Syndrome is 50%, which means there is also a 50% chance they wouldn’t have ACHOO Syndrome. The phenotypes the children could also experience as a result of not having ACHOO Syndrome could involve not sneezing uncontrollably when around bright light, but I can imagine them squinting their eyes at light instead as that’s a natural thing people do, but they wouldn’t sneeze unlike those with ACHOO Syndrome.