Achondroplasia is a rare autosomal dominant condition resulting in dwarfism. From 120,000 births at a large?
hospital over a number of years, 27 babies were born with this disorder. Of these babies, 4 had a dwarf parent. What is the apparent mutation rate of achondroplasia gene in this population?
Tagged with: babies • mutation rate • population
Filed under: Dwarfism
As half of all children born to a parent with this condition will not be affected, even if only 1 in 10 with the condition survived to delivery, the total number of parents with the gene will not impact the 120,000 significantly.
Since 4 of the 27 had a known parent with the condition (unknown parents could still exist), 23/120,000 (~1 in 5,200) is the mutation rate.
Note the assumptions in this calculation.