The Ins and Outs of Familial Hypercholesterolemia (FH)

What are the chances that an individual who is homozygous dominant for FH and an individual who is heterozygous would have a child with FH?

Final answer:

The chance that a homozygous dominant individual for familial hypercholesterolemia (FH) and a heterozygous individual would have a child affected by FH is 100%, as each child will always receive at least one dominant allele responsible for the disorder.

Genetic disorders like familial hypercholesterolemia (FH) follow specific inheritance patterns that can help predict the likelihood of passing on the disorder to offspring. In the case of FH, where one copy of the mutated gene is enough to cause the disorder, the probabilities are more straightforward.

When a homozygous dominant individual (FF) for FH and a heterozygous individual (Ff) have children, the chances of having a child with FH are guaranteed at 100%. This certainty stems from the fact that the homozygous dominant parent will always pass on a dominant allele, and the heterozygous parent has a 50% chance of passing on the dominant allele.

Therefore, every child born to this genetic pairing will inherit at least one dominant allele responsible for FH, resulting in all offspring being affected by the disorder. This predictable outcome is due to the autosomal dominant nature of FH, where the presence of a single dominant allele is sufficient for the disorder to manifest.

By applying Mendelian genetics principles to the genetic cross between a homozygous dominant (FF) and a heterozygous (Ff) parent, the probabilities become clearer. The Punnett square analysis would show that all offspring will either be homozygous dominant (FF) or heterozygous (Ff), leading to a 100% chance of inheriting FH.