Abstract
Familial Adenomatous Polyposis （FAP） had been thought to be an autosomal dominant inheritance disorder. But, recently researchers indicate that some FAP-patients have an autosomal recessive inheritance manner due to biallelic alterations of MYH gene. This finding have increased the significance of a genetic diagnosis in genetic counseling for FAP. Especially, identification of genetic mutations in FAP-patients without family history is so important to clarify the inheritance mode. A conventional DNA direct sequencing method could not detect pathogenic mutations of patients in approximately 20% of actual FAP-families. A novel technique, multiplex ligation-dependent probe amplification （MLPA）, will be expected contribution for the improvement of the detection rate, and will have highly clinical utility.
