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.
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.