A novel NR2F1-associated microdeletion underlying Bosch-Boonstra-Schaaf optic atrophy syndrome.

Background: Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) is a rare autosomal dominant neurodevelopmental disorder that typically presents in early childhood. It is characterized by intellectual disability, developmental delay, and visual impairment, with optic atrophy being the most prominent ophthalmologic feature. The nuclear receptor subfamily 2, group F, member 1 (NR2F1) gene is currently the only known causative gene associated with BBSOAS. To date, no cases of BBSOAS have been reported in the Japanese population.

Cases presentation: We reported a 13-year-old Japanese male suspected of having BBSOAS, who presented with decreased visual acuity due to bilateral optic atrophy, as well as intellectual disability and developmental delay. Microarray-based comparative genomic hybridization (array-CGH), followed by whole-genome sequencing (WGS), identified a novel de novo 1.48-Mb heterozygous microdeletion involving NR2F1.

Conclusions: This is the first reported case of BBSOAS in a Japanese patient. These findings highlight the utility of array-CGH and WGS as powerful tools for detecting NR2F1-related microdeletions. BBSOAS should be considered in the differential diagnosis of patients presenting with developmental delay, intellectual disability, and visual impairment, even in the absence of a family history.