The same characteristic Gillespie syndrome-like iris, with aplasia of the pupillary sphincter and a scalloped margin, is seen in ACTA2-related multisystemic smooth muscle dysfunction syndrome.
We describe a neonatal patient with fixed dilated pupils and pulmonary, bladder, and bowel dysfunction suspicious for the presence of ACTA2 R179 mediated multisystemic smooth muscle dysfunction syndrome.
Two patients with the heterozygous R189H mutation in ACTA2 and Complex congenital heart defects expands the cardiac phenotype of multisystemic smooth muscle dysfunction syndrome.
Mutations in the ACTA2 gene lead to a multisystemic smooth muscle dysfunction syndrome that causes vascular disease, congenital mydriasis, and variable presentation of urinary and gastrointestinal problems.
Mutations in ACTA2 are the most common genetic cause of thoracic aortic aneurysm, and are also the cause of other disorders, including Moyamoya disease, coronary artery disease and stroke as well as Multisystemic Smooth Muscle Dysfunction Syndrome.
A de novo mutation of the ACTA2 gene encoding the smooth muscle cell α-actin has been established in patients with multisystemic smooth muscle dysfunction syndrome associated with patent ductus arteriosus and mydriasis present at birth.