Daily Exam Question - Feb. 11, 2014 - Genetics
A Couple whose child has an autosomal recessive disease has what percent recurrence risk with each conception?
Answer: B - Technology Assessment Number 11, February 2014
The carrier of a gene that causes an autosomal recessive disease usually is recognized after the birth of an affected child, after the diagnosis of an affected family member or as the result of a genetic screening program. A couple whose child has an autosomal recessive disease has a 25% recurrence risk with each conception. The likelihood that normal sibling of an affected child is a carrier of the gene is 2 out of 3 (one fourth of all offspring will be homozygous normal, two fourths will be heterozygote carriers, and on fourth will be homozygous abnormal. Thus three of four children will be phenotypcaly normal and two of these three will be carriers