## ashlynn143 2 years ago If only a mother has achondroplasia, what are the chances a child will also have the condition?

1. ashlynn143

2. KarolinaJosephine

it's 50% because only the mother has it

3. ashlynn143

thank you for helping me the second time today!?!?!

I think I got it. Achondroplasia is gene defect, and a cause of dwarfism. People with this disorder have one mutant copy of the FGFR3 gene that causes the disorder, and one normal copy of the FGFR3 gene. If the parent passes on their mutant copy to their child, then the child will have achondroplasia. KarolinaJosephine is right. It is 50%, if only the mother has it. Let me draw a table, and show you. |dw:1352597562365:dw| The mother's genes are A and a. The father's genes are B and b. Let's look at the table, and pretend that A is the mutant gene. A is the gene that would give the child achondroplasia. There are 4 squares on the table, and 2 squares have A. That means there's a 50% chance the child will have achondroplasia, you see?

5. ashlynn143