Dentinogenesis imperfecta is a rare,autosomal,dominantly inherited disease of the teeth that occurs in about one in 8000 people.The teeth are somewhat brown in color,and the crowns wear down rapidly.Assume that a male with dentinogenesis imperfecta and no family history of the disease marries a woman with normal teeth.What is the probability that their first child will have dentinogenesis imperfecta?

Question

Quizplus · Accepted Answer

Since dentinogenesis imperfecta is an autosomal dominant condition, a person with the condition has at least one affected allele. If the male has the condition and no family history of it, he is likely heterozygous for the gene (one normal allele, one affected allele). The woman has normal teeth, implying she has two normal alleles. Therefore, each child has a 50% chance of inheriting the affected allele from the father and a 50% chance of inheriting a normal allele from each parent, resulting in a 1/2 probability of having the condition.

Dentinogenesis Imperfecta Is a Rare,autosomal,dominantly Inherited Disease of the Teeth