ACTA2 leukovasculopathy: A rare pediatric white matter disor
Smooth muscle cells form a lattice-like cellular matrix within blood vessels providing contractile functioning and homeostasis of vascular tone. Smooth muscle cells also synthesize proteins important for muscle remodeling and repair. Vascular smooth muscle cells are comprised in part by tissue-specific ?2-smoooth muscle actin which is encoded by ACTA2.

A 3-year-old girl presented with ataxia, dilated pupils, and behavioral change prompting work up for stroke. Her medical history included chronic mydriasis and patent ductus arteriosus requiring aortoplasty. Magnetic resonance imaging of the brain demonstrated confluent white matter signal abnormality concerning for leukodystrophy.

Magnetic resonance angiography revealed a cerebral vessel arteriopathy with a “broomstick appearance” and other neuroradiographic findings consistent with ACTA2 mutation. Pathogenic Arg179His ACTA2 mutation was confirmed in the patient.

ACTA2-related leukovasculopathy should be considered during workup of patients with abnormal white matter (eg, leukodystrophies), childhood stroke, and arteriopathies. Recognizing the combination of commonly associated physical and medical conditions associated with radiographic features of this neurogenetic condition will prompt appropriate care and screening for comorbidities associated with this disorder.