Sara and Mara are identical twin sisters. Their parents had

Last updated: 7/8/2022

Sara and Mara are identical twin sisters. Their parents had them late in their marriage, and they have two older siblings. Their father was diagnosed with Huntington's disease, a dominant monogenic disorder, shortly after his 50th birthday. Their older siblings were also diagnosed with the disease late in life; their sister Tamara was 52 at the time of diagnosis and their brother Jack was 53 when he was diagnosed. Sara and Mara's mother never showed signs of the disease. Sara is turning 50 next year, and is very concerned about her chances of also having Huntington's disease. So she looked into her family records and found out that her father's mother had Huntington's disease but not his father. With her family information, Sara performed a Punnett square and found out she has a 50% chance of having Huntington's disease. Based on this information, what can you say about Sara and Mara's parents? Their mother's genotype is hh and their father's genotype is HH. Their mother's genotype is Hh and their father's genotype is hh. Their mother's genotype is HH and their father's genotype is Hh. Their mother's genotype is hh and their father's genotype is Hh. Their mother's genotype is Hh and their father's genotype is Hh.