Isozyme genotypes

Reaction and rapid method for isozyme genotyping. Gene 93,271-275,1990 Weis,... 

New York City children, N = 1,278 Pb screening testing PbB and isozyme genotype Children with the 1-2 or 2-2 isozymes have PbB about 10 pg/dl higher than with the 1-1 genotype Wetmur et al. (1991b)... 

German Pb workers, N =202 Studied for PbB versus ALAD isozyme genotype Workers with ALAD2 allele had significantly higher PbB, 10 pg/dl Ziemsen et al. (1986)... 

The more recent literature on the relationship of Pb-B, 6-ALAD genotype, various other markers of Pb exposures, and various toxic endpoints is a complex, seemingly inconsistent body of information across the various studies and some of the information appears anomalous (Table 16.5). Some issues of concern are the relationship of isozyme genotype to general indicators of exposure intensity such as employment duration and intensity, other biomarkers of Pb exposure such as patellar or tibial bone Pb levels, and biomarkers of early effect such as ZPP, plasma ALA, urinary ALA, and clinical markers of effect such as those for renal function. 

There are few pharmacogenetic data for Hispanics. As previously stated, not every Hispanic subgroup has been phenotyped. To the best of our knowledge, our research unit is the only one that has reported on the results of CYP2D6 genotyping in Mexican Americans (Mendoza 1996). There are, however, data regarding isozymes that are thought to be fairly specific to Asians, Africans, and Spaniards. 

The frequencies of the homozygous usual genotype (UU), atypical (AA). and silent (SS) arc I person out of 1,3, 2500, and 110,000 individuals, respectively (Lockridge and Masson, 2000 Whittaker, 1986). Approximately 10% of Caucasians have llie C.5-(- isozyme. This variant has an approximately 25% higher activity than the usual BuChE. It has been reported that farmers with the C5+ isozyme are more resistant to intoxication by anticholinestera.se pesticides because BuChE is a scavenger of OPs and CMs (Akizuki et at, 2004 Fomoura-da-Silva and Chautard-Freire-Maia, 1996 Lockridge and Masson, 2000). 

Several studies probing more complex lead biokinetic questions with reference to ALAD genotype have appeared. For example, Schwartz et al. (1997) concluded that, in a group of 57 lead workers with either the ALAD 1-1 or 1-2 isozymes, those individuals with the variant 1-2 isozyme had lower bioavailable lead stores than the 1-1 isozyme subjects when challenged with DMSA as lead mobilizing agent. 

Unionized construction workers, N = 691 Measured PbB, bone Pb, indices of kidney function, ALAD genotypes Borderline association (p = 0.06) of ALAD2 isozyme variant with BUN Smith et al. (1995a)... 

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