New research on rhabdomyosarcoma genetics from University of Freiburg summarized
2007 APR 9 -- New research, "Uniparental disomy at chromosome 11p15.5 followed by HRAS mutations in embryonal rhabdomyosarcoma: lessons from Costello syndrome," is the subject of a report. According to a study from Freiburg, Germany, "Costello syndrome (CS; MIM 218040) is characterized by short stature, facial dysmorphism, cardiac defects and predisposition to embryonal rhabdomyosarcoma (CS/ERMS) and other neoplasias. CS is caused by germline mutations in the HRAS gene on chromosome 11p15.5, a region showing allelic imbalances in sporadic ERMS and CS/ERMS." "The critical gene for ERMS development in this region is unknown. The association of CS and ERMS as well as previous reports illustrating that somatic HRAS mutations are found in a proportion of these tumors prompted us to clarify the significance and a possible correlation of HRAS mutations and genomic rearrangements at 11p15.5 in sporadic ERMS. We screened for somatic HRAS mutations and 11p15.5 imbalances in six sporadic ERMS samples. This analysis uncovered five ERMS samples with uniparental disomy (UPD) at the HRAS locus, two of which harbored HRAS mutations. By analyzing informative genetic variations in or at the HRAS gene locus, we show that one HRAS allele is entirely lost in specimens with UPD at 11p15.5. Notably, in both cases with UPD and HRAS mutations these mutations were heterozygous. Therefore, they must have succeeded the emergence of UPD. In contrast, HRAS germline mutations are the first step in CS/ERMS. Subsequent development of UPD at 11p15.5 may explain previous observations that CS/ERMS express mutant HRAS only," wrote C.P. Kratz and colleagues, University of Freiburg. The researchers concluded: "These data implicate that in sporadic ERMS, UPD at 11p15.5 is not driven by HRAS mutations and that imbalances at 11p15.5 and HRAS mutations represent independent but cooperating events during ERMS development." Kratz and colleagues published the results of their research in Human Molecular Genetics (Uniparental disomy at chromosome 11p15.5 followed by HRAS mutations in embryonal rhabdomyosarcoma: lessons from Costello syndrome. Human Molecular Genetics, 2007;16(4):374-9). For additional information, contact C.P. Kratz, University of Freiburg, University of Freiburg, Dept. of Pediatrics and Adolescent Medicine, Mathildenstrasse 1, 79106 Freiburg, Germany. The publisher of the journal Human Molecular Genetics can be contacted at: Oxford University Press, Great Clarendon St., Oxford OX2 6DP, England. Keywords: Germany, Freiburg, Rhabdomyosarcoma Genetics, Costello Syndrome, Embryonal Rhabdomyosarcoma, Genetics, Myosarcoma, Oncology, Rhabdomyosarcoma. This article was prepared by Clinical Oncology Week editors from staff and other reports. Copyright 2007, Clinical Oncology Week via NewsRx.com.
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