Mapping of the human complement factor I gene to 4q25.

A detailed genetic and physical map of human complement factor I (IF) using somatic cell hybrids, in situ hybridization, and genetic linkage is reported. The gene has been localized to band 4q25. The order GC-INP10-ADH3-EGF-IF-IL2-MNS is proposed for genes on 4q on the basis of genetic and physical mapping techniques. A BclI polymorphism found with the IF probe demonstrated a maternal origin for a de novo deletion of chromosome 4 that was used in physically mapping the gene. The genetic and physical distances around band 4q24 suggest that 1 cM is approximately 1.2 million bp of DNA. This work provides a useful addition to the map of 4q.