Analysis of fumarate hydratase mutations in a population-based series of early onset uterine leiomyosarcoma patients.
Germline mutations in fumarate hydratase (FH) gene at 1q43 predispose to hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome. In HLRCC, the most common clinical features are leiomyomas of the skin and uterus, and in a subset of the families, renal cell cancer (RCC) and uterine leiomyosarcoma (ULMS) occur frequently at young age. This study was conducted to evaluate the possible contribution of FH mutations in a population-based series of early onset (< or = 45 years) ULMSs. Eighty-one cases were identified through the national cancer registry, and samples from 67 cases (83%) were available for FH mutation screening and analysis of allelic imbalance (AI) at the FH locus. Seventeen percent of tumors showed AI. In the mutation analysis, a novel missense mutation K424R was found. The mutation was also found from the patient's normal tissue. To study whether this variant has functional consequences, FH enzyme activity assay was performed in a cell model. The activity of the mutated protein was significantly reduced as compared to wild type (p = 0.009). This study shows that FH germline mutations can occur in seemingly nonsyndromic cases of ULMS (1/67, 1.5%). It appears that on the population level hereditary FH defects do play a role in pathogenesis of sporadic early onset ULMSs, albeit rarely.
Department of Medical Genetics, University of Helsinki, Biomedicum Helsinki, Haartmaninkatu 8, Finland.
Sanna K
SK
Ylisaukko-oja
Maija
M
Kiuru
Heli J
HJ
Lehtonen
Rainer
R
Lehtonen
Eero
E
Pukkala
Johanna
J
Arola
Virpi
V
Launonen
Lauri A
LA
Aaltonen
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D022981:Allelic Imbalance; D000595:Amino Acid Sequence; D001120:Arginine; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D005649:Fumarate Hydratase / Q000235:genetics*; D018095:Germ-Line Mutation; D006801:Humans; D007223:Infant; D007890:Leiomyosarcoma / Q000201:enzymology* / Q000235:genetics*; D008239:Lysine; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D014594:Uterine Neoplasms / Q000201:enzymology* / Q000235:genetics*
D004273:DNA, Neoplasm; D001120:Arginine; D005649:Fumarate Hydratase; D008239:Lysine