Protein S gene mutation in a young woman with type III protein S deficiency and venous thrombosis during pregnancy.
BACKGROUND
We attempted to identify a gene defect in a young woman with type III protein S deficiency and venous thrombosis during pregnancy.


METHODS
Measurements of total and free PS antigen levels in plasma were carried out using an enzyme-linked immunosorbent assay. Plasma PS cofactor activity was determined by a clotting assay using activated factor V as the substrate. Genomic DNA prepared from peripheral blood was amplified by polymerase chain reaction (PCR) with PROS1-specific oligonucleotide primers. PCR products were sequenced on both strands using specific oligonucleotide primers.


RESULTS
Plasma PS cofactor activity was undetectable in every measurement at 36 weeks of gestation, as well as at 2 weeks and 4 months after delivery. Plasma total PS antigen levels were 70% and 67% at 2 weeks and 4 months after delivery, respectively. Free PS antigen level was 24% at 4 months after delivery. Of all exons analyzed, codon 295 of GGC in exon 10 was substituted for AGC. This missense mutation predicted an amino acid change of glycine to serine.


CONCLUSIONS
Measurements of total and free PS antigen levels along with PS activity indicated that this was a case of type III PS deficiency. DNA analysis identified a heterozygous missense mutation of codon 295 in the PS gene, substituting glycine for serine.
Hirose
Masaya
M
Department of Obstetrics and Gynecology, Shiga University of Medical Science, Ohtsu, Japan. hirose@belle.shiga-med.ac.jp
Kimura
Fuminori
F
Wang
Hua-Qin
HQ
Takebayashi
Koichi
K
Kobayashi
Masashi
M
Nakanishi
Keiko
K
Akiyama
Minoru
M
Kimura
Toshio
T
Noda
Yoichi
Y
D000328:Adult; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D020125:Mutation, Missense; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000209:etiology; D017293:Protein S / Q000235:genetics*; D018455:Protein S Deficiency / Q000175:diagnosis / Q000235:genetics*; D020246:Venous Thrombosis / Q000235:genetics*
D017293:Protein S