A variable number of tandem repeats polymorphism influences the transcriptional activity of the neonatal Fc receptor α‐chain promoter

• DOI: 10.1111/j.1365-2567.2006.02408.x
• Publication Date: 2006-06-23T15:05:20Z
• Authors: Ulrich J. H. Sachs; Ines Socher; Christian G. Brae...; Hartmut Kroll; Gregor Bein; Sentot Santoso
• Keywords: Neonatal Fc receptor

Summary The neonatal Fc receptor, FcRn, plays a central role in immunoglobulin G (IgG) transport across placental barriers. Genetic variations of FcRn‐dependent the placenta may influence antibody‐mediated pathologies fetus and newborn. Sequencing analysis 20 unrelated individuals demonstrated no missense mutation within five exons FcRn gene. However, variable number tandem repeats (VNTR) region promoter was observed, consisting different alleles (VNTR1–VNTR5). Alleles with two (VNTR2) three (VNTR3) were found to be most common Caucasians (7·5 92·0%, respectively). Real‐time polymerase chain reaction revealed that monocytes from VNTR3 homozygous express 1·66‐fold more transcript than do VNTR2/VNTR3 heterozygous ( P = 0·002). In reporter plasmid assays, allele supported transcription gene twice as effectively did VNTR2 0·003). Finally, under acidic conditions, showed an increased binding polyvalent human IgG when compared 0·021). These data indicate VNTR polymorphism influences expression leading IgG‐binding capacities.