Myoadenylate deaminase deficiency: a clinical, genetic, and biochemical study in nine families.
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.
Sinkeler
S P
SP
Department of Neurology, University of Nijmegen, The Netherlands.
Joosten
E M
EM
Wevers
R A
RA
Oei
T L
TL
Jacobs
A E
AE
Veerkamp
J H
JH
Hamel
B C
BC
D000659:AMP Deaminase / Q000172:deficiency* / Q000235:genetics; D005080:Exercise Test; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D009709:Nucleotide Deaminases / Q000172:deficiency*; D010375:Pedigree
D009709:Nucleotide Deaminases; D000659:AMP Deaminase