SNP Shot: Genomic Insights

Venous malformations of the skin and mucous membranes (VMCM) appear as bluish spots or patches (lesions) on the skin (cutaneous) and in areas like the mouth and nose (mucosal membranes). These lesions occur because veins and other blood vessels beneath the surface have not developed normally (venous malformations). The lesions can cause pain, particularly if they spread from the skin to muscles and joints, or if calcium builds up inside them, leading to inflammation and swelling.

Most individuals with VMCM are born with at least one venous malformation. These birthmarks tend to grow larger over time, and new lesions frequently develop as the person gets older. The size, quantity, and location of these venous malformations can differ significantly from person to person, even within the same family.

Inheritance:

VMCM follows an autosomal dominant inheritance pattern. This means that having just one copy of the changed gene in each cell increases the likelihood of developing venous malformations. Some gene changes (mutations) happen during a person's life and only affect certain cells. These are called somatic mutations and are not passed down from parents. Researchers have found that some VMCM lesions contain both an inherited and a somatic mutation in the TEK gene. It's unclear whether the somatic mutation happens before or after the venous malformation develops. Because the lesions are localized and not all veins are malformed, it is believed that the inherited mutation alone is not sufficient to cause venous malformations. Typically, a person with VMCM has one parent who also has the condition.