Two cases of chromosome 4q35-linked early onset facioscapulohumeral muscular dystrophy with mental retardation and epilepsy.

Two cases of early onset facioscapulohumeral muscular dystrophy (FSHD) with mental retardation and epilepsy are reported. They were sporadic, unrelated, severely affected females. In both cases, Southern blot analysis of the EcoRI-digested genomic DNA, using probes p13E-11 and pFR-1, detected the shortest 10 kb EcoRI fragments reported to date. Patient 1 showed infantile spasms at the age of 4 months and localization-related epilepsy at the age of 2.5 years. Muscular atrophy in the face, shoulder girdle and upper arms was observed from the age of 4 years. In Patient 2, lack of facial expression was noticed since the age of 1 year, and at 4 years she was noted to have a loss of bilateral upward gaze. She developed localization-related epilepsy at the age of 9 years. From the age of 10 years, weakness of the lower limbs progressed and she became wheelchair-bound at the age of 14 years and 8 months. She had moderate sensorineural hearing loss, a loss of bilateral upward gaze and tongue atrophy. Their IQs were 33 and 45, respectively. The two patients suggest that mental retardation and epilepsy may be part of the clinical spectrum of FSHD, especially in very early onset patients with large deletions.