Genotype establishments for protein C deficiency by use of a DNA polymorphism in the gene.
During the course of structural gene analyses for protein C deficiency, we have confirmed that a T or G nucleotide variation is present at exon 6 of the protein C gene. This single-base substitution was located at the third nucleotide coding for Ser (TCT) at 99 residue, and neither produces an amino acid substitution nor creates a new restriction enzyme site. By using mutagenic primers that could introduce A instead of G at the third nucleotide 3' to the de novo polymorphic site, we have created the polymorphic Xba I site (T/CTAGA) in a more-frequent allele. Polymerase chain reaction using these mutagenic primers and subsequent Xba I digestion of 20 normal Japanese genomic samples showed that the frequency of this new sequence polymorphism designated as PC-493 was 0.18 and that the estimated heterozygosity rate was 28.9%. In Caucasians, the frequency of this polymorphism was 0.25, and a significant difference did not exist between Japanese and Caucasian populations. The examination of the haplotype inter-relationships with PC-493 and the Msp I polymorphism 5' to the protein C gene established that PC-493 gave a 16.7% chance of new information per individual for people who were previously homozygous for the Msp I polymorphism. We have performed a family study of the protein C-deficient pedigree using this sequence polymorphism, and found that the PC-493 DNA polymorphism was a useful marker for tracing the affected gene in protein C-deficient family members.
First Department of Internal Medicine, Nagoya University School of Medicine, Japan.
K
K
Yamamoto
M
M
Tanimoto
T
T
Matsushita
K
K
Kagami
I
I
Sugiura
M
M
Hamaguchi
J
J
Takamatsu
H
H
Saito
D001483:Base Sequence; D002675:Child, Preschool; D015252:Deoxyribonucleases, Type II Site-Specific; D005091:Exons; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006023:Glycoproteins / Q000276:immunology / Q000502:physiology; D006239:Haplotypes; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010375:Pedigree; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011486:Protein C / Q000235:genetics; D020151:Protein C Deficiency; D017293:Protein S
D006023:Glycoproteins; D011486:Protein C; D017293:Protein S; C025580:endodeoxyribonuclease XBAI; D015252:Deoxyribonucleases, Type II Site-Specific