Abstract
This case report provides a detailed examination of a rare co-occurrence of Costello syndrome, euryblepharon, and Moyamoya syndrome in a 14-year-old female. Costello syndrome, a rare genetic disorder characterized by developmental delays, distinctive facial characteristics, and a predisposition to certain malignancies, presents an array of ocular manifestations, including downward-slanting palpebral fissures. A significant similarity is noted with euryblepharon, a rare periocular anomaly marked by the downward slanting of the eyelids. Despite these striking resemblances, the association between euryblepharon and Costello syndrome is yet to be documented in the literature. Furthermore, the coexistence of Costello syndrome and Moyamoya syndrome, a cerebrovascular disorder, is exceedingly rare. This report provides an in-depth analysis of the patient's ocular and periocular manifestations, establishing a potential association of euryblepharon within the phenotypic spectrum of Costello syndrome and documenting the unusual co-occurrence with Moyamoya syndrome. These findings aim to augment our understanding of Costello syndrome's phenotypic variability and potential associations.