Adenylosuccinate lyase (ASL) deficiency
Incidence
Some 20 pts have been reported. It is an AR disease. It is a defect of purine biosynthesis. The gene is located in chromosome 22.
Clinical Characteristics
There is profound mental retardation. Austistic features may be present in 50% of the pts. There is epilepsy and bipyramidal syndrome. Some pts have FTT. CSF protein is low. CT scan show hypoplasia of cerebellar vermis. Large amounts of succinyladenosine and succinylaminoimidazole carboxamide riboside (succinyl Z riboside) accumulate in body fluids, detected by thin-layer chromatography (TLC) or cathion-exchange chromatography due to deficiency of the enzyme (ASL). Rapid diagnostic test in urine has been developed. No treatment has been demonstrated effective.
Precipitants
no
Provocation Tests
no
Diagnostic Procedures
CSF protein is low. Large amounts of succinyladenosine and succinylaminoimidazole carboxamide riboside (succinyl Z riboside) accumulate in body fluids detected by thin-layer chromatography (TLC) or cathion-exchange chromatography. Rapid diagnostic test in urine has been developed.