(Landouzy Dejerine type)
FACIO-SCAPULO-HUMERAL FORM is affects both sexes. Average age of onset is 12-14 years, but it may start at any age. The earliest muscles involved are those of the face and then the disease progreses centrifugally to shoulder girdle and upper arm muscles. Disablement occurs during puberty. Facial weakness (Myopathic facies) may exist for many years before the development of weakness anywhere. Due to facial weakness there is difficulty in blowing up balloons or whistling. All facial muscles particularly orbicularies oris are affected. In advanced cases lordosis and scoliosis may develop. The disease progreses very slowly. Most patients remain ambulatory until middle or later life. Contracture or pseudohypertrophy is absent. Life span is normal. The gene causing this disorder has been located to the long arm of chromosome 4.