A 30 year girl individual whose father has Huntington disease requests genetic testing to determine if she has inherited the mutation. She is so far asymptomatic. What should he counselled?

At 30 years of age, she would already have shown symptoms if she had inherited the mutation.

She faces a 50-50 risk of developing symptoms of Huntington disease.

She remains at risk at age 30, though his risk is less than 50% being asymptomatic at this age.

The fact that her father was the affected parent indicates that she must not have inherited the gene, since paternally-transmitted Huntington disease has onset in childhood.