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ABSTRACT: Myoadenylate deaminase deficiency is the most common metabolic disorder of skeletal muscle in the Caucasian population, affecting approximately 2% of all individuals. Although most deficient subjects are asymptomatic, some suffer from exercise-induced myalgia suggesting a causal relationship between a lack of enzyme activity and muscle function. In addition, carriers of this derangement in purine nucleotide catabolism may have an adaptive advantage related to clinical outcome in heart disease. The molecular basis of myoadenylate deaminase deficiency in Caucasians has been attributed to a single mutant allele characterized by double C to T transitions at nucleotides +34 and +143 in mRNA encoded by the AMPD1 gene. Polymerase chain reaction-based strategies have been developed to specifically identify this common mutant allele and are considered highly sensitive. Consequently, some laboratories preferentially use this technique over other available diagnostic tests for myoadenylate deaminase deficiency. We previously identified a G468-T mutation in one symptomatic patient who was only heterozygous for the common AMPD1 mutant allele. In this report, nine additional individuals with this compound heterozygous genotype are revealed in a survey of 48 patients with documented deficiency of skeletal muscle adenosine monophosphate deaminase and exercise-induced myalgia. Western blot analysis of leftover biopsy material from one of these individuals does not detect any immunoreactive myoadenylate deaminase polypeptide. Baculoviral expression of the G468-T mutant allele produces a Q156H substitution enzyme exhibiting labile catalytic activity. These combined results demonstrate that the G468-T transversion is dysfunctional and further indicate that AMPD1 alleles harboring this mutation contribute to the high incidence of partial and complete myoadenylate deaminase deficiency in the Caucasian population. Consequently, genetic tests for abnormal AMPD1 expression designed to diagnose patients with metabolic myopathy, and to evaluate genetic markers for clinical outcome in heart disease should not be based solely on the detection of a single mutant allele.
Neuromuscular Disorders 09/2002; 12(6):558-65. · 2.80 Impact Factor
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ABSTRACT: A fast, simple, safe and inexpensive method for purification of genomic DNA from blood samples for subsequent PCR is described. All steps are carried out in a single 1.5 ml reaction tube. Neither proteinase K digestion nor precipitation steps are involved. The method is highly efficient. As little as 20 microl of whole blood gives enough DNA for reliable amplification by PCR. The blood cells are lysated in a buffer, the nuclei are pelleted and resuspended in water after a wash step. The resuspension is directly used for PCR.
European journal of medical research 03/1998; 3(3):173-5. · 1.13 Impact Factor
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ABSTRACT: We determined the DNA sequence of the adenylosuccinate lyase (ASL) gene from a 13 year-old female, who showed a reduced ASL enzymatic activity in lymphocytes and red blood cells and suffered from severe psychomotor retardation. The patient was the offspring of a non-consanguineous marriage. She was found to be compound heterozygous for two missense-mutations located on different alleles (C300-G and G1266-T): the first mutation replaces Pro75 by Ala, the second mutation replaces Asp397 by Tyr.
Biochimica et Biophysica Acta 03/1998; 1406(1):81-4. · 4.66 Impact Factor
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Advances in experimental medicine and biology 02/1998; 431:323-5. · 1.09 Impact Factor
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Advances in experimental medicine and biology 02/1998; 431:129-33. · 1.09 Impact Factor
