Medical Genetics Genetic Risk Relationship relatedness 0% 20%4%60% Iden tical twin 100% 46% Offspring of two patien ts 46% i Fraternal twin 50% 14% Offspring of one patient 50% 13% Sling 50% 10% Neph ew or niece 25% 3% spouse 0% 2% Unrelated per son in the 1% gene al populatonMedical Genetics