It may be due to the presence of low frequency null alleles
segregating at these loci as described by Peter et al.
These mismatches can be ascribed to the presence of allelic drop-out, null alleles
or high frequency of mutations resulting in 2-4 bp shifts.
The molecular basis of a microsatellite null allele
from the White Sands pupfish.
The null alleles
affect population parameters which are estimated based on the proportion of heterozygotes.
[22-24]detected different null alleles
, including Wx-A1.
Comparing these data and our results using a population of 60 Mexicans with chronic periodontitis, an increase in the frequency of the GSTM1 null allele
to 55% is observed and our data indicate that the GSTT1 null allele
is present at a frequency of 65%.
Taken together, the observations from the genetic crosses described above and the cuticle analyses suggest that the [hth.sup.CPTI000378] allele is not a null allele
and support the view that the [hth.sup.CPTI000378] lethality is likely due to a second site mutation.
All apparently homozygous undisputed mothers who had a different STR phenotype to their apparently homozygous children were counted as probable null allele
2009), which suggests there may be null alleles
at these loci.
When Shriver, who considers himself to be white, analyzed his own DNA, he found that it contained the Duffy null allele
, found only in descendants of sub-Saharan Africans.