The genotype of an individual with a rare autosomal dominant condition can be denoted by the letters “Aa” (heterozygous) or “AA” (homozygous). Only one capital A is required to have the disease (assuming full penetrance). Unaffected individuals would have a genotype “aa.” A Punnett Square can be created which reveals possible offspring for Aa x aa and would have genotypes “Aa” (50%) or “aa.” (50%). These are interpreted as the risk for each pregnancy - the offspring has a 50% chance of inheriting the condition and 50% of not inheriting the condition. For AA x aa, the offspring has a 100% chance of having the disease. Therefore, the most accurate statement is to say that the child has at least a 50% chance of having the condition with each pregnancy. It is inaccurate to say that 50% of their offspring will definitely have the condition. Additionally, because the condition is autosomal dominant, 25% chance of inheriting is inappropriate.