A kindred with MYH-associated polyposis and pilomatricomas.
MYH-associated polyposis (MAP) is a recently described autosomal recessive form of familial adenomatous polyposis (FAP) associated with susceptibility to colorectal carcinoma (CRC). MAP is caused by biallelic inactivating mutations of the MYH gene, a component of the base excision repair (BER) machinery, whose dysfunction leads to an increase in the rate of G > T transversions following DNA oxidative damage. MAP patients can present with either classic or attenuated polyposis. However, the MAP colonic and extracolonic phenotype has yet to be defined. We report on two siblings, born from consanguineous parents, who were found to be homozygotes for an MYH frameshift mutation. The propositus presented with a low number of colonic lesions and an early-onset CRC. Both siblings had a history of pilomatricomas, benign tumors derived from hair follicles, in childhood. The findings presented provide further evidence of phenotypic variability in MAP, and suggest that multiple pilomatricomas may be a useful cutaneous marker of MAP.
Baglioni
Silvana
S
Department of Clinical Pathophysiology, Section of Medical Genetics, University of Florence, Florence, Italy.
Melean
German
G
Gensini
Francesca
F
Santucci
Marco
M
Scatizzi
Marco
M
Papi
Laura
L
Genuardi
Maurizio
M
D011125:Adenomatous Polyposis Coli / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D000328:Adult; D003241:Consanguinity; D004247:DNA / Q000737:chemistry / Q000235:genetics; D045647:DNA Glycosylases / Q000235:genetics*; D004252:DNA Mutational Analysis; D005192:Family Health; D005260:Female; D016368:Frameshift Mutation; D006201:Hair Diseases / Q000473:pathology*; D006801:Humans; D008297:Male; D010375:Pedigree; D018296:Pilomatrixoma / Q000473:pathology*; D018807:Polymorphism, Single-Stranded Conformational; D035781:Siblings; D012878:Skin Neoplasms / Q000473:pathology*
D004247:DNA; D045647:DNA Glycosylases; C061738:mutY adenine glycosylase