Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Myoadenylate deaminase (MADA) is an enzyme which participates in the purine nucleotide cycle necessary for energy production in human skeletal muscle. Approximately 35 patients with deficiency of this enzyme have been reported; one-half experienced their initial difficulties in childhood. Children with "primary" MADA deficiency typically have symptoms including muscle cramps, stiffness, and post-exercise myalgia and weakness. In "secondary" MADA deficiency, the clinical findings have been variable with delayed motor development, hypotonia, cardiomyopathy, delayed speech development, and generalized weakness. In most cases creatine kinase determinations, nerve conduction velocity studies, and routine muscle histopathology have been normal. Diagnosis has been established by demonstrating an absence of MADA activity by either direct muscle enzyme assay or histochemical staining. In this report we describe a 12-year-old boy with primary MADA deficiency and contrast his symptoms with those of previously described pediatric patients.
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PMID:Myoadenylate deaminase deficiency in children. 391 3

A 2-yr-old boy had congenital hypotonia, limb weakness, exercise intolerance and one episode of myoglobinuria. Histochemical and biochemical analysis of muscle showed a combined defect of phosphorylase and AMP deaminase. DNA analysis showed that the child was homozygous for the mutations commonly found in both McArdle's disease and AMP deaminase deficiency. The father was heterozygous for both mutations. The mother was heterozygous for the myophosphorylase gene mutation and homozygous for the mutation in the AMP deaminase 1 gene.
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PMID:Double trouble: combined myophosphorylase and AMP deaminase deficiency in a child homozygous for nonsense mutations at both loci. 758 Feb 37