Molecular and biochemical characterization of the GALT gene in Korean patients with galactose-1-phosphate uridyltransferase deficiency.
BACKGROUND
Three different types of galactosemia have been described, and the most common form occurs due to a deficiency in the galactose-1-phosphate uridyltransferase (GALT) enzyme activity.


METHODS
To investigate the molecular defects of the GALT gene, PCR-direct sequencing was performed with genomic DNA from 18 Korean patients with reduced GALT activity.


RESULTS
Of the 18 patients tested, 13 (72.2%) had previously reported variants: Duarte variant (12 patients), p.R201H (1 patient), and g.A1962G. In addition, we identified six novel sequence variations by PCR-direct sequencing: five sequence variations in coding regions (p.H31R, p.L116I, p.Q169H, p.H186P and p.R333R), and one in an intron (g.2621A>G). Of 100 normal individuals tested, 4 were heterozygous for the Duarte variant, which indicates a Duarte allele frequency of 2%. Biochemical characteristics of the novel genetic alterations were determined: enzyme activity for exonic alterations and splicing for intron.


CONCLUSIONS
The genetic constitution of the GALT gene is responsible for galactosemia in the Korean population.
Ko
Dae-Hyun
DH
Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, South Korea.
Chang
Ho Eun
HE
Song
Sang Hoon
SH
Park
Kyoung Un
KU
Kim
Jin Q
JQ
Kim
Min-Chang
MC
Song
Young-Han
YH
Hong
Yong Hee
YH
Lee
Dong Hwan
DH
Song
Junghan
J
D004252:DNA Mutational Analysis; D005091:Exons / Q000235:genetics; D005693:Galactosemias / Q000209:etiology / Q000235:genetics*; D014644:Genetic Variation; D015894:Genome, Human; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007438:Introns / Q000235:genetics; D007723:Korea; D005694:UTP-Hexose-1-Phosphate Uridylyltransferase / Q000172:deficiency* / Q000235:genetics*
D005694:UTP-Hexose-1-Phosphate Uridylyltransferase