null mutation


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Related to null mutation: frameshift mutation

null mutation

1. A change in DNA or RNA that does not result in any change in the protein product or content of a cell.
2. A change in a nucleotide that results in the complete failure of protein synthesis by a cell.
See also: mutation

null mutation

A mutation that eliminates the function of the affected gene. In many cases the null mutation is a complete deletion of the gene.
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Our results supported the previously published findings reporting an association between the GSTM1 null mutation and endometriosis (23,34).
The type of LDLR gene mutation was coded by use of 2 dummy categorical variables: null mutations vs missense mutations (1 for null mutations, 0 for splicing mutations, 0 for missense mutations) and splicing mutations vs missense mutations (0 for null mutations, 1 for splicing mutations, 0 for missense mutations).
The initial study carried out in 2000 found that FANCA individuals with homozygous null mutations had a higher frequency of somatic anomalies than individuals with FANCC mutations, but a similar frequency to those with FANCG mutations.
They found 7 African Americans with null mutations in PCSK9.
It is caused by null mutations at WRN locus, which codes for a member of RecQ family of DNA helicases.
Residual guanosine 3', 5'-bispyrophosphate synthetic activity of relA null mutants can be eliminated by spoT null mutations.
pylori is caused by null mutations in the rdxA gene and less frequently by mutations in frxA and fdxB genes.
Null mutations in lin-14, for example, result in the activation of LIN-29 one stage too early, with the result that certain adult features are precociously expressed in larval stages.
sup][5] derived a global IV clinical severity score (0–15) by scoring each of five IV clinical signs (diffuse xerosis, hyperlinearity of palms, scales on legs, scalp desquamation, and keratosis pilaris) from 0 to 3 points and genotyping two common FLG null mutations (R501X and 2282del4) for 110 Caucasian patients.
The authors analyzed the phenotype of mouse embryos harboring an atRA-sensitive reporter transgene or bearing null mutations for atRA-syntbesizing enzymes or atRA receptors after maternal exposure to either 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or atRA on gestation day 10.