Autosomal dominant polycystic kidney disease (ADPKD) is an inherited genetic disorder characterized by the growth of numerous fluid-filled cysts in the kidneys. These cysts can enlarge and eventually lead to kidney failure. Symptoms, such as high blood pressure and loin pain, typically do not appear until a person is between 30 and 50 years of age.
The disease is caused by a dominant allele (DDD) and not the recessive allele (ddd).
A homozygous recessive female mates with a heterozygous male.
Use a genetic diagram to show the parental genotypes, the gametes produced, and the possible genotypes and phenotypes of the offspring.
Explain why it is difficult for a doctor to determine if an asymptomatic 18-year-old has inherited ADPKD based solely on a physical examination.
Suggest what other diagnostic tools or information a doctor could use to confirm whether the 18-year-old will develop the disease.
Some other inherited kidney conditions, such as autosomal recessive polycystic kidney disease (ARPKD), are caused by recessive alleles rather than dominant alleles.
Explain how examining a family pedigree diagram would enable you to determine if a genetic condition is caused by a recessive allele.
