Figure 4 Growth of information in MIM concerning mapping of genes and genetic loci to specific human chromosomes in the period up to the initiation of the Human Genome (Sequencing) Project. In 1968, when the first gene was assigned to a specific autosome (the Duffy blood group to the centromeric region of chromosome 1),27 MIM recorded 68 X-linked phenotypes with an asterisk, indicating confidence in X-linked inheritance.