title: Myoadenylate deaminase deficiency: a clinical, genetic, and biochemical study in nine families.
abstract: The clinical significance of myoadenylate deaminase (MAD) deficiency and its mode of inheritance is still questioned. There were 36 relatives of 9 unrelated MAD deficient patients who were examined with the aid of a standardized ischemic forearm test: 8 new cases of MAD deficiency were detected, 5 of which were confirmed histochemically and biochemically. Obligate heterozygotes showed a normal ammonia production and MAD staining, but the mean activity of the enzyme was significantly less than in a group of controls. The results obtained from the family study strongly suggest an autosomal recessive mode of inheritance. However, only 2 of the 8 newly found MAD deficient individuals complained of exertional myalgia, whereas the remaining 6 were without any symptoms or complaints. This finding casts doubt on the clinical significance of MAD deficiency and the relationship of the deficiency state with exertional myalgia.
authors.affiliation: Department of Neurology, University of Nijmegen, The Netherlands.
authors.forename: S P
authors.initials: SP
authors.lastname: Sinkeler
authors.forename: E M
authors.initials: EM
authors.lastname: Joosten
authors.forename: R A
authors.initials: RA
authors.lastname: Wevers
authors.forename: T L
authors.initials: TL
authors.lastname: Oei
authors.forename: A E
authors.initials: AE
authors.lastname: Jacobs
authors.forename: J H
authors.initials: JH
authors.lastname: Veerkamp
authors.forename: B C
authors.initials: BC
authors.lastname: Hamel
mesh_terms: D000659:AMP Deaminase / Q000172:deficiency* / Q000235:genetics; D005080:Exercise Test; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D009709:Nucleotide Deaminases / Q000172:deficiency*; D010375:Pedigree
chemical_list: D009709:Nucleotide Deaminases; D000659:AMP Deaminase