A multistage cost-effective strategy for the molecular diagnosis of unexplained vision loss patients: practice in inherited ocular fundus disease.

Inherited ocular fundus diseases are the most common causes of blindness with high heterogeneity. We established a tiered strategy for the molecular diagnosis of unexplained vision loss patients. Patients were screened with ophthalmological examinations followed by a tiered genetic diagnosis, including mitochondrial genome sequencing, multigene panel and whole exome sequencing. A total of 146 individuals with unexplained vision loss were enrolled, including 103 individuals with abnormal pattern visual evoked potential and 43 individuals with abnormal optic coherence tomography. Based on our tiered strategy for molecular diagnosis, 33 cases were diagnosed with Leber's hereditary optic neuropathy, with common or very rare mitochondrial variants. Moreover, 22 cases with monogenic disorders were diagnosed with 15 novel and 16 reported mutations. Our study reveals the genetic etiology of unexplained vision loss and expands the genetic variation spectrum. The tiered cost-effective strategy for molecular diagnosis improves genetic detection rates and is expected to be applied to future clinical practice.