BioBeyond – Disease Detective Practice Exam

To determine the probability that Jamal's newborn will have sickle-cell disease (SS), it's important to consider the genetic inheritance pattern of this condition. Sickle-cell disease occurs in individuals who are homozygous for the sickle-cell allele (genotype SS).

If we know Jamal's own genotype, we can assess the likelihood of his child inheriting the disease. For a child to inherit sickle-cell disease, both parents must contribute a sickle-cell allele. If Jamal is a carrier (heterozygous genotype AS) or unaffected (normal genotype AA), the probability of having a child with the SS genotype will vary. However, if Jamal is confirmed to have the genotype AA (indicating he does not carry the sickle-cell allele), he cannot pass on a sickle-cell allele to his child.

In the absence of more information about the mother’s genotype and assuming Jamal is normal (AA), there's no chance of having an SS child. Therefore, the probability that Jamal's newborn will have sickle-cell disease is indeed 0%, as there are no sickle-cell alleles to pass on. This conclusion aligns with the genetic understanding of inheritance patterns for sickle-cell disease and why having no alle