Not exact matches
Of the Iron Age individuals, three carry at least one Duffy
null allele, protecting against malaria, and two have at least one sleeping - sickness - resistance variant
in the APOL1 gene.
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.
In contrast to two hemizygous XPDXPCS patients carrying the XPDG47R - or XPDR666W - encoding alleles who died of the disease before 2 y of age, two compound heterozygous XPDXPCS patients carrying the same XPDG47R - or XPDR666W - encoding alleles in addition to the presumed null XPDL461V + del716 − 730 both had considerably milder disease symptoms and survived more than ten times longer (A. Lehmann, personal communication)(Figure 5
In contrast to two hemizygous XPDXPCS patients carrying the XPDG47R - or XPDR666W - encoding
alleles who died of the disease before 2 y of age, two compound heterozygous XPDXPCS patients carrying the same XPDG47R - or XPDR666W - encoding
alleles in addition to the presumed null XPDL461V + del716 − 730 both had considerably milder disease symptoms and survived more than ten times longer (A. Lehmann, personal communication)(Figure 5
in addition to the presumed
null XPDL461V + del716 − 730 both had considerably milder disease symptoms and survived more than ten times longer (A. Lehmann, personal communication)(Figure 5).
Recently, proteins originating from presumed
null alleles were biochemically characterised as inactive
in basal transcription [27], providing an explanation as to why these
alleles failed to rescue lethality
in haploid S. pombe with a
null mutation
in the XPD homologue rad15 [19].
Examples of compound heterozygous patients
in which a second, presumed
null allele is likely to contribute to disease outcome are provided above
in comparison to corresponding homo - or hemizygous patients with the same causative
allele.
Our data suggest a re-evaluation of the contribution of «
null»
alleles to XPD disorders and highlight the potential of combinations of recessive
alleles to affect both normal and pathological phenotypic plasticity
in mammals.
Some of these
alleles fail to support viability
in a haploid Schizosaccharomyces pombe yeast strain with a
null mutation
in the XPD homologue rad15 and are thus considered devoid of significant biological activity [19].
Flpe - and Cre - mediated recombination
in vitro generated ES cell lines that contained a conditional or
null Sema3B
allele, respectively, which were established as homozygous
alleles in mice.
In a first step knock - out models with conditional potential (knock - out first
allele, tm1a) will be produced from which tm1b
null alleles can be derived for phenotyping
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).
The entire coding region of the progranulin gene was deleted
in the
null allele.
To test for heterozygote deficiency, as might result from the presence of
null (nonamplifying)
alleles or inadvertent pooling of subpopulations (Wahlund 1928), we tested 1 - tailed probabilities of departure from Hardy - Weinberg equilibrium, using the Markov chain exact test
in GENEPOP.