Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serum carnosinase deficiency with carnosinuria has been reported in 23 children with neurological signs and/or mental retardation. In adults four cases in one family had serum carnosinase deficiency, carnosinuria, and in addition elevated homocarnosine in CSF and in the brain. The mother was one of these cases but had no clinical symptoms; however her three children have spastic paraparesis, retinitis pigmentosa and mental retardation. Serum carnosinase deficiency alone is not the cause of the neurological symptoms. When two of the affected children consumed carnosine, anserine or homocarnosine, they metabolized these compounds much less rapidly than did two normal control individuals.
 ...
PMID:Inborn errors of carnosine and homocarnosine metabolism. 235 6

Serum carnosinase deficiency (McKusick 21220) is a rare condition, described in 13 cases. Ten additional individuals with serum carnosinase deficiency have been identified. All continued to excrete increased amounts of carnosine in their urine despite a meat-free diet for 3 days. Serum carnosinase activity ranged from 0-30% of normal. In four individuals a normal Km for carnosine of 0.12 mM was observed, while in five individuals an increased Km was found. Homocarnosine levels in CSF in three individuals ranged from 3.4 to 15 mM. Clinical symptoms in these individuals were as follows: attention deficit disorder: 4; non progressive developmental delay: 1; neurofibromatosis: 1; absences seizures: 1; severe, but non-progressive mental retardation, seizures and neurosensory hearing loss: 1; progressive childhood dementia; 1; clinically normal: 1. There was no correlation between severity and type of the neurological symptoms and residual serum carnosinase activity. Although a definite conclusion can only be made after a considerably higher number of individuals has been analyzed, the suspicion that serum carnosinase deficiency is unrelated to the neurological symptoms is strengthened by these observations. There may, however, be an association with a predisposition for mental deficiency.
 ...
PMID:Serum carnosinase deficiency: a non-disabling phenotype? 409 64