Plasminogen with type-I mutation in the Chinese Han population

Area of Science:

• Human Genetics
• Molecular Biology
• Biochemistry

Background:

• A functionally inactive plasminogen (PLG) variant, PLG M5, characterized by a type-I mutation (codon 601), is known to be polymorphic in the Japanese population.
• This mutation results in a GCT to ACT amino acid change, affecting plasminogen's biochemical properties.

Purpose of the Study:

• To investigate the presence and frequency of the plasminogen type-I mutation in the Chinese Han population.
• To assess the functional consequences of this mutation on plasminogen activity in affected individuals.

Main Methods:

• Phenotyping of plasminogen variants in 104 healthy Chinese students.
• Polymerase Chain Reaction (PCR) and allele-specific oligonucleotide (ASO) dot-blot hybridization to detect the type-I mutation in the PLG gene.
• Measurement of plasma immunoreactive plasminogen concentrations and plasminogen activities.

Main Results:

• The PLG M5 phenotype, associated with the type-I mutation, was identified in 2.9% (3 out of 104) of the Chinese Han students.
• Individuals with the PLG M5 phenotype exhibited normal plasma immunoreactive plasminogen levels but significantly decreased plasminogen activities.
• PCR and ASO dot-blot analysis confirmed the presence of the type-I mutation in the PLG gene of these individuals.

Conclusions:

• The plasminogen type-I mutation is present in the Chinese Han population.
• This genetic variant appears to be polymorphic within this population, with potential implications for hemostasis and thrombosis.
• The study confirms that the type-I mutation leads to reduced plasminogen activity, irrespective of geographic origin.