Reader response: A family-based study into penetrance in facioscapulohumeral muscular dystrophy type 1.

Abstract

We read with interest the article reporting on facioscapulohumeral muscular dystrophy (FSHD) type 1 probands and their relatives. Penetrance of FSHD, based on muscle symptoms, depends on D4Z4 repeat size and continues to increase in adulthood.1 It would be interesting to study the penetrance of retinal vasculopathy in this family by using optical coherence tomography angiography, a noninvasive imaging technique that acquires volumetric angiographic information without the use of a dye. Indeed, according to the existing literature, only a systematic examination of eye fundus can detect telangiectasia and aneurysms, which may be present early in life before evidence of muscle disease.2 Very few complaints related to retinal alteration have been reported by patients with FSHD, as retinal lesions rarely affect the macula. A more severe retinal vasculopathy, known as Coats-like retinopathy, is observed by fluorescein angiography in 40%–75% of patients with FSHD. However, retinal findings prior to the diagnosis of FSHD are only detected in very rare cases.3–5