Molecular analysis of 11 galactosemia patients.

Galactosemia is a human inborn error of galactose metabolism due to deficiency of galactose-1-phosphate uridyl transferase. In this paper, I describe the molecular analysis of genomic DNA, mRNA and protein from 11 different galactosemic patients by Southern, Northern and Western blotting. The results of these experiments lead me to conclude that galactosemia is caused mostly by missense mutations. The unusual preponderance of missense mutations in galactosemia led me to investigate its cause. I demonstrate that all 9 patients I investigated have detectable residual enzyme activity (ranging from 0.7-6.9% of normal). This finding is of potential importance in addressing the long-term complications of galactosemia.