Polymorphisms of the mannose binding lectin gene in patients with Sjögren's syndrome.

OBJECTIVE To investigate polymorphisms of both codon 54 allele and promoter variants of the mannose binding lectin (MBL) gene in patients with primary Sjögren's syndrome (SS). METHODS Polymorphisms of codon 54 allele and promoter variants of the MBL gene in 104 patients with SS and 143 healthy controls were determined by polymerase chain reaction-restriction fragment length polymorphism and allele specific polymerase chain reaction respectively. RESULTS The allele frequency of the wild type of MBL codon 54 was significantly higher in patients with SS than in controls (0.836 v 0.741; p=0.011), and the frequency of the homozygous wild type of MBL codon 54 was significantly higher in patients with SS than in controls (0.692 v 0.539; p=0.024). On the other hand, the allele frequencies of the MBL promoter gene did not differ between patients and controls (chi(2)=4.01, df=2, p=0.135). CONCLUSION The polymorphism of the MBL gene may be one of the genetic factors that determines susceptibility to SS.