Rare Syndrome Heightens Risk of Bone Cancer

A certain class of mutations in a gene associated with the rare Rothmund-Thomson Syndrome appears to increase the risk of osteosarcoma, a form of bone cancer, said researchers from Baylor College of Medicine and Texas Children’s Cancer Center in the current issue of the Journal of the National Cancer Institute.

“We found that two-thirds of the patients we studied had gene mutations that resulted in prematurely shortened or cut off or inactive protein,” said Lisa L. Wang, M.D., assistant professor of pediatrics at Baylor and lead author on the study. When the protein is truncated, it cannot carry out its normal cellular function.

The gene in question – RECQL4 – is involved in basic cell functions such as the translation of genes into proteins and DNA repair. Mutations that result in an inactive RECQL4 protein could lead to malignant change, she said. RECQL4 is what is known as a DNA helicase – one of five known in humans. Two other helicases are associated with cancer-prone syndromes.

People with Rothmund-Thomson syndrome have a characteristic skin rash, small stature and abnormalities of the skeleton, and many have various other problems associated with the syndrome.

In the 33 patients Wang studied, 23 had mutations of the RECQL4 gene and that resulted in truncated or inactive proteins. All 11 patients in the 33 who had osteosarcoma had these types of mutations.

Ten of these patients did not have mutations in the RECQL4 gene may mean that mutations in a different gene can also cause this syndrome. In this case, it appears that the disease is not associated with osteosarcoma, said Wang.

– Lori Williams

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©2006 Texas Medical Center

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