Renal glucose reabsorption.
Answer:
Brachydactyly and Huntington's are phenotypic conditions that occur when a person possesses one or two dominant alleles for those traits.
John's father has Huntington's disease but does not have brachydactyly, which means his genotype is Hh/bb.
John's mother, who is healthy and has brachydactyly, likely has a genotype of hh/BB or hh/Bb.
