First frameshift mutation in the active protein S gene associated with a quantitative hereditary deficiency.

The authors used a strategy combining the amplification-refractory mutations system (ARMS) and denaturing gradient gel electrophoresis (DGGE) to screen the active protein S (PS) gene in a family with PS deficiency, and found a frameshift mutation in exon V. The protein, if expressed, would have an aberrant amino acid sequence from positions 82 to 90 and a premature stop codon in position 91. The mutation co-segregated with the deficient phenotype and was not found in 120 normal chromosomes. It is proposed that the deletion of a T in the codon corresponding to Pro 82 described here is responsible for the deficient phenotype.