THE FIRST REPORT OF BILATERAL EARLY-ONSET CORNEAL ECTASIA ASSOCIATED WITH AN SLC10A7 MUTATION: COMPREHENSIVE OCULAR EVALUATION AND PHENOTYPIC CHARACTERIZATION

To present the first documented case of bilateral early-onset corneal ectasia in a pediatric patient with a confirmed SLC10A7 mutation, expanding the ocular phenotype associated with short stature, amelogenesis imperfecta, and skeletal dysplasia with scoliosis (SSASKS)

The patient was followed up at İstanbul University - Cerrahpaşa Faculty of Medicine, İstanbul, Turkey, in 2025.

A six-year-old boy with genetically confirmed SLC10A7 mutation underwent a detailed ophthalmologic examination including refraction, orthoptic testing, slit-lamp biomicroscopy, spectral-domain OCT, and corneal tomography (Pentacam). Whole-exome sequencing revealed a homozygous pathogenic variant (NM_001029998.6: c.529_530del; p.Val177Cysfs19*) classified as pathogenic by ACMG criteria. Systemic findings included amelogenesis imperfecta, short stature, and skeletal dysplasia.

Best-corrected visual acuity was 8/10 in the right eye and 7/10 in the left. Cycloplegic refraction indicated hyperopic astigmatism. Orthoptic evaluation showed a 50-prism-diopter alternating esotropia with right-eye occlusion therapy. Slit-lamp examination demonstrated clear corneas with mild blue sclera. Corneal tomography revealed bilateral stromal thinning and posterior elevation (OD thinnest 407 µm, BAD-D 3.22, Kmax 42.4 D; OS thinnest 421 µm, BAD-D 3.10, Kmax 42.3 D), suggesting an early ectatic pattern inconsistent with classical keratoconus. Fundus and macular OCT were normal. Axial lengths were 21.78 mm (OD) and 21.62 mm (OS), indicating compact ocular morphology. Corneal cross-linking was deferred due to the nonprogressive course, and regular follow-up was advised.

This report describes the first association between SLC10A7 mutation and bilateral corneal ectasia. The findings support the hypothesis that SLC10A7-related extracellular matrix dysregulation can extend to the cornea, leading to early stromal thinning and biomechanical fragility. Comprehensive corneal tomography should be routinely performed in SSASKS patients and other connective-tissue disorders to detect early corneal alterations and reduce amblyopia risk.