TUESDAY, Dec. 14 (HealthDay News) -- Scientists report that they have advanced their knowledge of genetic mutations associated with adrenal gland tumors by identifying 13 new potential variations.

Tumors called pheochromocytomas can affect the adrenal gland, which is located above the kidney. These tumors -- which are usually benign but can also be cancerous -- cause the adrenal gland to produce too much adrenaline, resulting in high blood pressure, headaches, heart palpitations, nausea and vomiting.

In the new study, which included nearly 1,000 people, the researchers identified 19 mutations in the FP/TMEM127 gene that may be associated with pheochromocytomas in the adrenal gland.

"Of these, 19 mutations found in 20 patients were considered of potential pathogenic significance. Thirteen of these variants were [new], while the remainder had been previously reported," Li Yao, of the University of Texas Health Science Center at San Antonio, and colleagues wrote in the report published in the Dec. 15 issue of the Journal of the American Medical Association.

The average age of patients when they developed FP/TMEM127-mutated tumors was 42.8 years and median (midpoint) age was 41.5 years.

"These observations support the existence of additional pheochromocytoma susceptibility genes, which may account for some of the genetically undefined cases," the authors wrote in a news release from the journal's publisher.

More information

The American Urological Association has more about pheochromocytoma.