X-Linked Idiopathic Infantile Nystagmus (XLIIN): Case Report and Review of Literature

Abstract

Infantile nystagmus syndrome (INS) is one of the most common forms of nystagmus. It can occur in isolation or with other ocular anomalies. While nystagmus is usually sporadic, familial cases exist and are most commonly X-linked with incomplete penetrance and variable expressivity. There are over 45 mutations reported in the FRMD7 gene. This review describes the possible underlying mechanisms of infantile nystagmus syndrome, clinical characterization, and principles of management including behavioral, refractive, pharmacological, and surgical options as well as determines the genetic basis of INS in one large Caucasian family with a novel mutation in FRMD7. Newer generation optical coherence tomography (OCT) allows for accurate phenotypical characterization of genetic subtypes of INS. Further studies into identifying unknown genetic mutations involved in infantile nystagmus syndrome will allow for development of cellular and animal models to help classify INS and guide future therapies.