Galactosemia in the Turkish population with a high frequency of Q188R mutation and distribution of Duarte-1 and Duarte-2 variations.
Classical galactosemia is an inherited recessive disorder of galactose metabolism caused by deficiency of the enzyme galactose-1-phosphate uridyl transferase (GALT), which is caused by mutations in the GALT gene. In this study, 56 Turkish patients diagnosed with galactosemia were screened for GALT gene mutations using Affymetrix resequencing microarrays. Eleven types of mutations were detected in these patients, including two novel mutations (R258G and G310fsX49) and nine recurrent mutations. We detected six patients who were homozygous for the E340* mutation and for N314D, L218L silent substitutions (Duarte-1 variant) in this study. The haplotype E340*, N314D and L218L has been reported only in Turkish patients, which suggests that the E340* mutation is specific for our population and might be spread by a Turk ancestor. In patients, the Duarte-1 allele was found with a frequency of 10.71%, whereas the Duarte-2 allele was not detected. Duarte-1 and Duarte-2 alleles were found to be present at a frequency of 2.3% and 1.4%, respectively, in the screening of 105 healthy individuals. Considering all detected mutations, it is a very important finding that exons 6 and 10 of the GALT gene account for 79% of all mutant alleles in the Turkish population. The most common mutation is Q188R, with a frequency of 55.35%.
1] Metabolism Unit, Department of Pediatrics, Faculty of Medicine, Hacettepe University, Ankara, Turkey [2] Institute of Child Health, Hacettepe University, Ankara, Turkey.
Rıza Köksal
RK
Özgül
Ayşegül
A
Güzel-Ozantürk
Halil
H
Dündar
Didem
D
Yücel-Yılmaz
Turgay
T
Coşkun
Serap
S
Sivri
Sultan
S
Aydoǧdu
Ayşegül
A
Tokatlı
Ali
A
Dursun
D000483:Alleles; D044466:Asian People / Q000235:genetics*; D005091:Exons; D005693:Galactosemias / Q000453:epidemiology* / Q000235:genetics*; D005787:Gene Frequency; D020868:Gene Silencing; D014644:Genetic Variation; D006720:Homozygote; D006801:Humans; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D017422:Sequence Analysis, DNA; D014421:Turkey; D005694:UTP-Hexose-1-Phosphate Uridylyltransferase / Q000235:genetics*
D005694:UTP-Hexose-1-Phosphate Uridylyltransferase