CLINICAL AND BIOCHEMICAL-EVIDENCE OF SKELETAL-MUSCLE INVOLVEMENT IN GALACTOSE-1-PHOSPHATE URIDYL TRANSFERASE DEFICIENCY

A 8-year-old boy with galactose-1-phosphate uridyl transferase (GALT) deficiency presented with hypotonia, muscle hypotrophy, hepatomegaly, bilateral cataract and mild mental retardation. Two brothers showed a GALT activity consistent with a homozygotic condition and both parents were found to be heterozygotes for this defect. Histological and ultr astructural examination of muscle biopsy specimens showed several necr otic fibres. GALT activity was undetectable in skeletal muscle and mus cle tissue cultures; myotubes converted galactose to CO2 at a lower ra te than controls. Galactose-1-phosphate was increased in the patient's red cells and muscle tissue. GALT deficiency, not previously describe d in muscle, may be of pathogenic relevance in determining the myopath ic features present in GALT deficiency syndrome.