ABSTRACT
In humans, hyper IgM syndrome is also encountered in females, in whom it has an inheritance pattern in many families that suggests autosomal recessive inheritance (Fig. 12.1). The defective gene of the autosomal recessive form was mapped in several informative families to the short arm of chromosome 12, in a region that corresponds to the region containing the AID gene in mice. This prompted the search for a link between hyper IgM syndrome and AID deficiency in humans, and several cases of the autosomal recessive form were found to have mutations in the AID gene.
