A recent study found a high prevalence of a missense mutation (S135L) in the gene for galactose 1-phosphate uridyltransferase (GALT) in black children with galactosemia (J Pediatr 1996 ; 128 : 89-95).
In the present study, GALT activity and GALT protein content were measured in erythrocytes and leukocytes of eight black and seven white galactosemic (GALT-deficient) children, for correlation with the presence of the S135L and Q188R (highly prevalent in white galactosemic children) missense mutations.
The S135L mutation was found in 9 of 16 alleles of black children but not in white children ; the Q188R mutation was found in 10 of 14 alleles examined in white galactosemic children and in 4 of 16 alleles in black galactosemic children.
The GALT activity was near zero in the erythrocytes of white and black galactosemic children (0.26 ± 0.28 vs 0.33 ± 0.25 mumol/hr per gram of hemoglobin, respectively ; p=0.61) (normal 17 to 26 mumol/hr per gram), and no correlation of erythrocyte activity with genotype was observed.
The GALT activity was higher in the leukocytes of black galactosemic children compared with white children (5 ± 6 vs 1 ± 2 mumol/hr per gram, respectively) (normal 172 to 374 mumol/hr per gram), but the difference was not statistically significant (p=0.11).
Analysis by genotype revealed that the two S135L homozygotes had much more leukocyte activity (9 and 17 mumol/hr per gram) than Q188R homozygotes or than all non-S135L allelic genotypes. (...)
Mots-clés Pascal : Galactosémie, Prévalence, Négroïde, Exploration immunologique, Forme immunoréactive, Protéine, Erythrocyte, Leucocyte, Mutation, Etude comparative, Evaluation, Enfant, Homme, Etats Unis, Amérique du Nord, Amérique, Glucide, Métabolisme pathologie, Maladie héréditaire, Enzymopathie, Immunopathologie, Déterminisme génétique, Pédiatrie, Hémogramme
Mots-clés Pascal anglais : Galactosemia, Prevalence, Negroid, Immunological investigation, Immunoreactive form, Proteins, Red blood cell, Leukocyte, Mutation, Comparative study, Evaluation, Child, Human, United States, North America, America, Carbohydrate, Metabolic diseases, Genetic disease, Enzymopathy, Immunopathology, Genetic inheritance, Pediatrics, Blood cell count
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0369222
Code Inist : 002B02N. Création : 12/09/1997.