A healthy couple has a child diagnosed with a severe autosomal dominant skeletal disorder. Genetic testing reveals a pathogenic variant in the FGFR3 gene. Genetic testing of the parent's blood identifies that neither parent carries the variant, and there is no family history of the condition. The couple is concerned about the risk of recurrence in future pregnancies and asks whether the variant could be inherited again. Which of the
following statements is most likely correct about this situation?

Question

A healthy couple has a child diagnosed with a severe autosomal dominant skeletal disorder. Genetic testing reveals a pathogenic variant in the  FGFR3  gene. Genetic testing of the parent's blood identifies that neither parent carries the variant, and there is no family history of the condition. The couple is concerned about the risk of recurrence in future pregnancies and asks whether the variant could be inherited again. Which of the
following statements is most likely correct about this situation?

Accepted Answer

The variant likely occurred de novo in a parental germ cell, and recurrence risk is low but not zero due to possible germline mosaicism

Answer

The variant must have occurred during fertilization and will always be passed on to future offspring of this couple

Answer

The variant is recessive and both parents are carriers, so recurrence risk is 25%

Answer

The variant was inherited from a grandparent and skipped a generation due to incomplete penetrance

Crowdly

A healthy couple has a child diagnosed with a severe autosomal dominant skeleta...

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