Hereditary changes in genes are often the cause of rare diseases. For example, disease-causing gene variants (PVs) in the HRAS gene cause Costello syndrome and PVs in the KRAS gene cause Noonan syndrome and cardio-facio-cutaneous syndrome. If such PVs only arise during embryonic development in the womb, those affected suffer from a mosaic disease in which both altered and healthy cells are present.
In this context, researchers at the Hannover Medical School (MHH) and the National Cancer Institute (NCI) in the U.S. have, for the first time, analyzed the cancer risk within a special group of young patients.
The results make it clear how important close cancer monitoring is, with 20% of those affected being diagnosed with cancer by the age of just 20. Looking at rhabdomyosarcoma alone, the risk of developing the disease was 800 times higher than in the population as a whole. The findings are published in the journal Clinical Cancer Research .
Special high-risk group "We were able to include a total of 69 cases in the study. We observed twelve cancers, mainly in young children," explains Professor Dr. Christian Kratz, Director of the Department of Paediatric Haematology and Oncology at the MHH and initiator of the study.
Professor Kratz's team only included patients with multi-line mosaic RASopathies in the study. RASopathies are a group of developmental disorders caused by a dysregulation in genes of the RAS-MAPK signaling pathway. The study analyzed PVs in the HRAS or KRAS gene.