Mutations in corneal carbohydrate sulfotransferase 6 gene (CHST6) cause macular corneal dystrophy in Iceland.
OBJECTIVE
Macular corneal dystrophy (MCD) is subdivided into three immunophenotypes (MCD types I, IA and II). Recently, mutations in the carbohydrate sulfotransferase 6 gene (CHST6) were identified to cause MCD. The purpose of this study was to examine CHST6 for mutations in Icelandic patients with MCD type I.


METHODS
Genomic DNA was extracted from leukocytes in the peripheral blood and the coding region of CHST6 was examined for mutations by polymerase chain reaction (PCR) and direct sequencing.


RESULTS
Mutation analysis of the CHST6 coding region identified three different mutations in sixteen Icelandic patients with MCD type I. Eleven patients with MCD type I were homozygous for a C1075T mutation. One patient with MCD type I was found to be a compound heterozygous for C1075T and G1189C mutations. One family with MCD type I contained a 10 base pair insertion (ATGCTGTGCG) between nucleotides 707 and 708. In this family, two affected siblings had a homozygous insertion while both their affected mother and their affected maternal aunt had a heterozygous insertion and a heterozygous C1075T mutation.


CONCLUSIONS
Three different nucleotide changes were identified in the coding region of CHST6 in sixteen Icelandic patients with MCD type I. All three of these alterations are predicted to affect the translated protein and each of them corresponded to a particular disease haplotype that we had previously reported in this population.
Liu
N P
NP
Department of Ophthalmology and Center for Human Genetics, Duke University Medical Center, Durham, NC 27710, USA. nliu001@yahoo.com
Dew-Knight
S
S
Rayner
M
M
Jonasson
F
F
Akama
T O
TO
Fukuda
M N
MN
Bao
W
W
Gilbert
J R
JR
Vance
J M
JM
Klintworth
G K
GK
D001483:Base Sequence; D003315:Cornea / Q000201:enzymology* / Q000473:pathology; D003317:Corneal Dystrophies, Hereditary / Q000201:enzymology / Q000453:epidemiology / Q000235:genetics*; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000737:chemistry; D005260:Female; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D016133:Polymerase Chain Reaction; D015238:Sulfotransferases / Q000235:genetics*; D000097811:Carbohydrate Sulfotransferases
D017931:DNA Primers; D015238:Sulfotransferases; D000097811:Carbohydrate Sulfotransferases