Abstract
Ophthalmological abnormalities in facioscapulohumeral dystrophy may lead to treatable vision loss, facilitate diagnostics, could help unravelling the pathophysiology and serve as biomarkers. In this study, we provide a detailed description of the ophthalmological findings in a well-defined cohort of patients with facioscapulohumeral dystrophy using state of the art retina imaging techniques. Thirty-three genetically confirmed patients (aged 7–80 years) and 24 unrelated healthy controls (aged 6–68 years) underwent clinical ophthalmological examination, fundus photography, optical coherence tomography/angiography, genotyping and neurological examination. All patients had normal corrected visual acuity and normal intraocular pressure. In 27 of the 33 patients, weakness of the orbicularis oculi was observed. Central retinal pathology, only seen in patients and not in healthy controls, included twisting (tortuosity) of the retinal arteries in 25 of the 33 patients and retinal pigment epithelium defects in 4 of the 33 patients. Asymmetrical foveal hypoplasia was present in three patients, and exudative abnormalities were observed in one patient. There was a correlation between the severity of retinal tortuosity and the D4Z4 repeat array size (R2 = 0.44, P < 0.005). Follow-up examination in a subgroup of six patients did not show any changes after 2 years. To conclude, retinal abnormalities were frequent but almost always subclinical in patients with facioscapulohumeral dystrophy and consisted primarily of arterial tortuosity and foveal abnormalities. Retinal tortuosity was seen in the retinal arterioles and correlated with the D4Z4 repeat array size, thereby providing clinical evidence for an underlying genetic linkage between the retina and facioscapulohumeral dystrophy.
Mutations in DNMT3B Modify Epigenetic Repression of the D4Z4 Repeat and the Penetrance of Facioscapulohumeral Dystrophy
