Vascular Type EDS is inherited in an autosomal dominant
manner. About half of call cases occur in people whose families have no
history of the disorder. These sporadic cases are caused by new
mutations in one copy of the COL3A1 gene.
It is important to note that parental somatic mosaicism
for COL3A1 mutations has been documented in several families in which
two affected individuals have been born to unaffected parents.