Tay-Sachs disease is a rare neurodegenerative disease, inherited following an autosomal recessive pattern. Its prevalence in Eastern European Jewish population is estimated to be 1/1,600. Arnold, who is of European Jewish origin, is married to Rosaline, whose sister is affected with Tay-Sachs. Harold and Rosaline, both of which are not affected by Tay-Sachs, are expecting their first child, what is the likelihood that this child will be affected with Tay-Sachs