Congential Myopathy with Uniform Type 1 Fiber Predominance and Type 2 Fiber Hypoplasia: Report of One Case

A 2-month-old female infant, presented with frequent choking and cyanosis during feeding, and poor sucking capability since the age of 45 days. Growth retardation with body weight and length below the third percentile, and head girth below the tenth percentile, were noted on admission. Generalized hypotonia, mild proximal muscle weakness and diminished tendon reflex were also noted. A biopsy from the left quadriceps femoralis showed uniform type 1 fiber (90%) predominance, and a decrease in fiber size and number of type 2 fibers. A biopsy from her father revealed uniform type 1 predominance (99.8%) and 30% central nuclei change. The course of her illness was rather short, and the patient has developed normally since the age of 4 months. Significant improvement in muscle strength and normol intelligence were observed after 3 years of clinical follow-up.