“Twig-like” cerebral vessels are not pathognomonic for ACTA A2 mutations: A case report

Abstract

<jats:p> ACTA2 mutations are recently described genetically defined abnormalities of blood vessels in various organs of the body with specific abnormalities in cerebral vessels in the form of straightening of all cerebral arteries (“twig-like” pattern), stenosis/occlusions, proximal dilatation, and absent “moyamoya” type of collaterals. We describe a one-and-a half year-old girl child who presented with mild motor developmental delay and on neuroimaging showed septo-preoptic holoprosencephaly, diffuse radial polymicrogyria, and pontine hypoplasia along with magnetic resonance angiographic features suggestive of ACTA2 mutation type of cerebral vessels. However, genetic studies revealed no evidence of ACTA2 mutation, indicating that the “twig-like” pattern may not only be a pathognomonic feature of ACTA2 mutations. </jats:p>

Expanding the Distinctive Neuroimaging Phenotype of ACTA2 Mutations

“…In this patient, the posterior cerebral arteries are also severely straightened and are associated with abnormal radial gyration involving the posterior temporal lobes and marked brain stem compression (Fig 4). The vascular phenotype present in this patient is similar to that in the others and is only described in patients with ACTA2 mutation, with the exception of an isolated case report 17 in which a mutation was not found and brain images were very similar to those in our patient. Thus, even though it is possible that this patient (despite neurovascular findings) does not have an ACTA2 mutation, we think that the striking association between severe vascular and brain phenotypes in this subject is supportive of our hypothesis that brain abnormalities are secondary to vessel rigidity.…”