Baglioni et al. 2005 identified in a brother and sister, the offspring of first-cousin parents, an association of multiple adenomatous polyps of the colon with childhood pilomatricomas, a homozygous 2-bp insertion in exon 13 of the MUTYH gene, 1186insGG, resulting in a frame shift and a premature stop codon at position 438 [53]. This evidence concerns the gene MUTYH and pilomatrixoma.