This report concerns two patients with facioscapulohumeral muscular dystrophy (FSHD) whose facial weakness began in infancy. In both patients, biopsied muscle histology showed mild myogenic changes accompanied by some regenerating and some small angular fibers, while endomysial inflammatory cellular infiltration was observed in Patient 1. The finding that our very young patients had muscle histopathological findings compatible with classical FSHD supports the previously expressed view that muscle histopathology is not related to either age or duration of the disease. Although Patient 2 was a sporadic case, both patients had the abnormal EcoRI DNA fragment detected by Southern blot analysis with probes p13E-11 and pFR-1, a finding compatible with FSHD. This indicates that gene analysis of sporadic cases must be as significant as that of familial cases. This report on patients with very early-onset and with common muscle histopathological and molecular genetic findings should contribute to widening the clinical spectrum of FSHD.