Mutations in " CPOX " usually cause hereditary coproporphyria, an acute hepatic porphyria, however the K404E mutation in a homozygous or compound heterozygous state with a null allele cause the more severe harderoporphyria.
22.
A mouse expressing a null allele of the " ITGA7 " gene are viable, suggesting that alpha-7 integrin is not essential for normal myogenesis; however, these mice develop a phenotype that resembles muscular dystrophy.
23.
In many cases, strains carrying one of two types of alleles will be archived-a null allele used in the primary IMPC phenotyping pipeline and a conditional ready allele that allows tissue restricted knockouts via the Cre-Lox Recombination and FLP-FRT recombination systems.
24.
Individuals who are homozygous for a specific mutation ( K404E ) or compound heterozygous with a null allele in " CPOX " have a more severe erythropoietic porphyria, harderoporphyria, characterized by neonatal jaundice, hyperbilirubinemia, hepatosplenomegaly and skin lesions upon exposure to ultraviolet light.
25.
However they also found that if you have just one null allele ( what we call heterozygous for that gene ), then you may have a different hair colour on your head, but that you have an an increased likelihood of having red body hair.
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Typically need your null allele to be incorporated into the DNA from a strain with a different coat colour, since this is the way you can identify your founders ( 129 mice are white, and B6 mice are black-chimeric mice will be a patchwork of white and black ).
27.
CYP2C19 * 2 ( 19154G > A, rs4244285, Il264Met ) and CYP2C19 * 3 ( 17948G > A, rs4986893, His212X ) are loss-of-function null alleles; carriers of the CYP2C19 * 3 but not the CYP2C19 * 2 allele showed a " reduced " risk of developing essential hypertension in a large Korean population study.
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And then you can define that section, whether it is a null allele with a DNA deletion or a gene duplication or some more complicated scramble, as an " allele ", and say that one organism has that allele while the other has the boring allele with one copy of the gene you expect.
29.
An HLA allele coding non-expressed gene is termed " Null Allele ", for example : HLA-B * 15 : 01 : 01 : 02N . The expression level can also detected by serotyping, an HLA gene coding for antigens which has low protein expression on the cell surface is termed " Low Expresser ", for example : HLA-A * 02 : 01 : 01 : 02L.
