Bill and Bob are biological twins who were adopted as babies. Their adoptive father and his father and his father (Billy and Bob’s father, paternal grandfather, and paternal great-grandfather) all suffered from early-onset fingernail greening. Which of the following statements is most likely to be the case?
Being adopted, it’s unlikely that Bill or Bob are at risk.
We know from the prompt that the adopted Bill and Bob, although twins, do not share their genetics with their adoptive father. It’s unlikely that Bill or Bob have inherited the genes that would turn their nails green at an early age.