Early-onset facioscapulohumeral muscular dystrophy

Abstract

While much is known about the clinical course of adult FSHD, the third most common inherited muscular dystrophy, data on the “infantile phenotype” and especially on the progression of the disease in children are limited. We followed a patient with infantile FSHD for 4 years and here report the clinical and genetic findings. Infantile FSHD is relatively rare. Despite some variability in the progression, infantile FSHD has a more consistent phenotype than adult FSHD. Although they had normal motor milestones, all patients showed facial weakness from early childhood, and subsequently were severely affected with rapid progression of the disease, marked muscular wasting, weakness, and hyperlordosis. Associated nonskeletal muscle manifestations include high-frequency hearing loss as well as retinal telangiectasias, both of which are rarely symptomatic, also cardiac involvement, restrictive respiratory disease, mental retardation and seizures. Our patient has not shown signs of nocturnal hypoventilation or cardiomyopathy so far. He has very short fragment sizes of the D4Z4 repeat. We conclude that infantile FSHD is a severe and rapidly progressive disease, and this needs to be taken into account in the advice given to patients diagnosed in early childhood.