What is Ehlers-Danlos Syndrome?
Ehlers-Danlos Syndromes (EDS) are a group of thirteen genetic disorders that affect connective tissue. All the variants of EDS are grouped together due to similar symptoms, so they are all genetically unique from each other and therefore are all different conditions that are distinct from one another. Each type is completely separate and having one does not increase the probability of having another.
Because all the types are separate from one another, you cannot inherit a different type than your parents and the type you have cannot develop into another at any stage. Additionally, it is extremely unlikely (though possible) that an individual will have more than one form of EDS. However, the severity of the EDS symptoms can vary within a family.
It is estimated that all types of EDS affects between 1 in 10,000 people to 1 in 25,000 people. This includes classic EDS, hypermobile EDS, and vascular EDS, among others.
What is Vascular Ehlers-Danlos Syndrome?
Vascular Ehlers-Danlos Syndrome, also known as vEDS, EDS type IV, or Sack-Barabas syndrome, is a rare form of EDS that affects the connective tissue in vessel walls and hollow organs. The symptoms of vEDS are caused by defects in type III collagen (a protein prevalent in connective tissue), which is caused by mutations in the COL3A1 gene (or rarely the COL1A1 gene which affects type I collagen) (Malfait et al., 2017). The defective collagen causes weakness in hollow organ and vessel walls, as normally collagen provides strength and structure to the connective tissues in these organs.
The disorder is characterised by aneurysms, organ rupture, and significant bruising, among other symptoms. Because of the possibility of sudden organ or arterial rupture, vEDS is considered the most severe form of EDS. It is also one of the rarer forms of EDS, affecting from 1 in 50,000 to 1 in 200,000 people (Byers et al., 2017). There is no ethnic predisposition to vEDS (Germain, 2007).
There is not currently standardised treatment for vEDS, however management and surveillance of the condition with a well-informed support team improves outlook.
Mutations in the COL3A1 gene is inherited in an autosomal dominant pattern, meaning the child of someone affected with vEDS has a 50% chance of inheriting the disease. De novo mutations and sporadic cases of vEDS account for approximately half of all cases (Garmain, D., 2007).
If a child is born with this mutation, they will always have the disease. However, the presentation of symptoms can occur at any age varying from person to person. 25% of people with vEDS experience major complications by the age of 20, and more than 80% experience major complications before they are 40. The median life expectancy for individuals with vEDS in approximately 50 years old. Males have a lower life expectancy as they have a higher rate of lethal vascular ruptures before 20 (Pepin et al., 1999).