Researchers of the de Duve Institute discovered that mutations in a gene called TEK cause Bean syndrome, a rare, severe blood vessel disorder. In earlier research, the group showed that mutations in the same gene also cause certain other blood vessel disorders. TEK is known to play a role in the formation of blood vessels, and the mutations cause lesions by disturbing a signaling mechanism in the cells that form the interior surface of blood vessels. This makes the cells misshapen, more invasive, and longer-lived. Medicines interfering with this signaling mechanism seem to be capable of ameliorating these diseases.
The researchers found the mutations by examining surgically excised lesional tissue from 17 patients with Bean syndrome. The mutations are somatic, i.e., present only in cells in the lesion but not in other cells of the body, and therefore non-inheritable. Interestingly, tissues from most patients had not one but two different mutations, both on the same allele (copy) of the gene.
Bean syndrome (BRBN or Blue rubber bleb nevus syndrome) is characterized by tens to hundreds of blue-purple lesions on the skin. Lesions also occur in the gastrointestinal tract, most commonly in the small intestine, and lead to bleeding, obstruction or even intestinal infarction. The lesions often increase in size and number with age. Most patients require repeated, life-long treatment to relieve their symptoms. Many need abdominal surgery to remove lesions or stop bleeding. There is no cure for the disease.
The researchers of the De Duve Institute cooperated with fourteen clinics and research institutions from all over the world in this research. The results were recently published in the Journal of Investigative Dermatology (Soblet et al., 2016).
From Left to right: Rafael Helaers, Mirta Basha, Matthieu Schögel, Julie Soblet, Nisha Limaye, Ha-Long Nguyen, Mélanie Uebelhoer, Pascal Brouillard, Antonella Mendola, Audrey Debue, Liliana Niculescu, Anne Van Egeren, Dominique Cottem, Mustapha Amyere, Miikka Vikkula
Soblet J, Kangas J, Nätynki M, Mendola A, Helaers R, Uebelhoer M, Kaakinen M, Cordisco M, Dompmartin A, Enjolras O, Holden S, Irvine AD, Kangesu L, Léauté-Labrèze C, Lanoel A, Lokmic Z, Maas S, McAleer MA, Penington A, Rieu P, Syed S, van der Vleuten C, Watson R, Fishman SJ, Mulliken JB, Eklund L, Limaye N, Boon LM, Vikkula M. Blue Rubber Bleb Nevus (BRBN) Syndrome is caused by Somatic TEK (TIE2) Mutations. J Invest Dermatol. 2016 [Epub ahead of print]