Genetics of Hemangioma
We have had a lot of discussion on face-book concerning the genetic/inheritance of hemangioma. It is the generally understood that infantile hemangioma is sporadic, that there is not an inheritance pattern. However there has been some families where it has appeared that there was more of an incidence then the rest of the population. This has cause concern for many parents, wondering if a sibling might also have a significant hemangioma.
First lets go over some basic terminology:
Congenital- simply means you were born with it. This does not necessarily mean that it is inherited for that it was passed down from your parents.
Genetic:- when this term is used it may mean that there is an inheritance pattern but it may also simply mean that a mutation or change in the gene occurred randomly.
Inherited- this is the term that when used is meant that there is a known inherited link in a family. There are many diseases that run in families, that there is a genetic cause that is passed down.
This is an over simplification of things but it will help you keep things straight.
In vascular anomalies we have two main groups. Tumors and Malformations.
The most common benign vascular tumor is the Infantile Hemangioma. It is this lesion that primarily occurs randomly. There is also the Congenital Hemangioma either the RICH or NICH forms. These are less common and while the child is born with a fully formed hemangioma it is not known to be inherited.
There are many types of vascular malformations. Malformations may occur in the veins, arteries, smaller vessels and even the lymphatic vessels.
Scientists have identified Genes and markers associated with malformations and hemangiomas. They have been able to test for the presence of the genes and markers to help distinguish between the types of anomalies.
MOST vascular anomalies are considered non-hereditary. Through the detailed analysis they have discovered inheritance forms of some vascular anomalies. They have identified mutations in genes that have cause familial malformations in RARE cases.
*Tie-2 gene (angiopoietin receptor): in mucocutaneous venous malformations (VMCM0
*Glomulin: in glomuvenous malformations (GVM)
*RASA1: in campllary malformations-arteriovenous malformations (CM-AVM)
The identification of these genes has allowed for more accurate and precise diagnosis, differential diagnosis, evaluation of variability in patients with known mutations and the study of treatments in identified patients. Identification of these genes will allow the clinician to determine the type of vascular anomaly and differentiate between malformation and tumor.
In infantile hemangioma there was an identified gene in one family that appeared in the published work of Doug Marchuk at Duke University. There have also been identified biomarks that have helped researchers understand the pathogenesis of hemangioma and to distinguish between infantile hemangioma/congenital hemangioma and malformations. At this time hemangioma is still primarily considered to be occurring sporadically.
Vikkula, M; Pathogenesis and Genetics of Vascular Anomalies, Ann Chir Plast Esthet, 2006 Aug-oct 51(4-5) .
Nauyen, VA; Kutzner, H; Furhapter, C; tzankov, A; Sepp, N, Infantile hemangioma is porliferation of LYVE-1-Negative blood endothelial cells without lymphatic competence, Modern Pathology, 2006 Feb:192(2):291-8
Mulliken, John, Enjolras, Odile, Congenital Hemangioma and Infantile Hemangioma: missing links. Journal of American Academy of Dermatology, July 2004; (875-881)