G to A mutation in the splice donor site of exon 1. The P{EPg}NotumEPg31259 insertion is also still present on the chromosome.
G16023920A
G?A
The Notum1 mutation was induced on the NotumEPg31259 chromosome which carries a P{EPg} insertion approximately 1kb upstream of Notum. It is a mutation in the splice donor from GT to AT.