The frequency of heritable mutations in the SMAD4 and BMPR1A gene in unselected individuals with Juvenile polyposis is approximately 60%. Large deletions account for ~14% and promoter mutation in BMPR1A a further 10%.
Of the heritable mutations identified in SMAD4 and BMPR1A genes, approximately 25% are de novo rather than being inherited.
||Probability of detecting a heritable mutation
|Patient has a first or second degree relative with documented pathogenic mutation