Our data suggest that certain presumed null alleles, although unable on their own to support basal transcription, may in fact have a substantial impact on disease outcome in compound heterozygous humans, as they do in mouse models. (journals.plos.org)
Short guide RNA was targeted to the sequence corresponding to the CCHa2 peptide - coding region, resulting in the isolation of putative null alleles for CCHa2 (CCHa2CR - 1, CCHa2CR - 2, and CCHa2CR - 3)(Figs 5A and S5). (journals.plos.org)
Long PCR detection of the C4A null allele in B8 - C4AQ0 - C4B1 - DR3. (decode.com)