Inborn Errors of Purine and Pyrimidine Metabolism
|
For monitoring in vitro activity of purine metabolism enzymes NOVOCIB has developed a range of homogenous microplate assays that allow:
• Accurate estimation of enzyme activity directly expressed in nmol/h;
• Through continuous monitoring at 340nm in a convenient 96-well plate;
• By simultaneous analysis of up to 24 samples per plate in 1h;
• Without sample preparation.
Symptoms |
Cytosolic 5'-nucleotidase superactivity |
|||||
Arthritis |
X |
X |
||||
Ataxia |
X |
X |
X |
|||
Autistic features |
X |
X |
||||
Convulsions |
X |
|||||
Deafness |
X |
|||||
Growth retardation |
X |
|||||
Hypotonia |
X |
|||||
Kidney stones (uric acid) |
X |
X |
X |
|||
Muscle cramps |
X |
|||||
Psychomotor delay |
X |
X |
X |
|||
Recurrent infections |
X |
X |
||||
Renal insufficiency |
X |
X |
X |
|||
Self-mutilation |
X |
|||||
Hyperuricemia |
X |
X |
X |
Several inherited disorders of purine metabolism have been described. Most of them are associated with severe clinical manifestations, such as neurological abnormalities of complete deficiency of hypoxanthine-guanine phosphoribosyltransferase (Lesch-Nyhan syndrome); a fatal immunodeficiency syndrome in adenosine deaminase and purine nucleoside phosphorylase. Inherited nerve deafness and severe muscular hypotonia may accompany PP-ribose-P synthetase superactivity, a unique urolithiasis - in adenine phosphoribosyltransferase. Other disorders, such as ITP pyrophosphohydrolase deficiency, myoadenylate deaminase deficiency or XOR deficiency alone may neither have no evident clinical consequences or be relatively bening (1).
De novo biosynthesis | Catabolic pathway | Salvage |
PP-ribose-P synthetase |
Adenosine deaminase (ADA, EC 3.5.4.4) |
Hypoxanthine-guanine phosphoribosyltransferase (HGPRT, EC 2.4.2.8) |
AICAR-Transformylase/IMP-cyclohydrolase (ATIC, EC 3.5.4.10) |
AMP deaminase (AMPDA, EC 3.1.3.5) |
Adenine phosphoribosyltransferase (APRT, EC 2.4.2.7) |
S-adenosylhomocysteine hydrolase (SAHH, EC 4.3.2.2) |
Purine nucleoside phosphorylase (PNP, EC 2.4.2.1) |
|
Adenylosuccinase (ADSL, EC 4.3.2.2) |
ITP pyrophosphatase
(ITP-ase, EC 3.6.1.19) |
References 1. H. Anne Simmonds, J.A. Duley and P.M. Davies (1991) « Analysis of purines and pyrimidines in Blood, Urine and other physiological fluids » in Techniques in Diagnostic Human Biochemical Genetics. A Laboratory Manual. Pp. 397-424 |