Related Experiment Videos
Inheritance of von Willebrand factor deficiency in Doberman pinschers
J Moser1, K M Meyers, R H Russon
1Department of Pharmacology/Toxicology, Washington State University, Pullman 99164, USA.
Objective:
To determine the inheritance of von Willebrand factor (vWF) deficiency in Doberman Pinschers.
Design:
Prospective, observational study.
Animals:
26 adult Doberman Pinschers or mixed-breed dogs and 101 pups produced from 18 matings between adult dogs.
Procedure:
Measurement of plasma vWF concentrations in parents and progeny. On the basis of plasma vWF concentrations, dogs were grouped as normal (75 to 160 U of vWF/dl), midrange (> or = 30 and < 75 U of vWF/dl), or low (< 30 U of vWF/dl).
Results:
The percentile distribution of vWF concentrations was trimodal. Distribution between dogs with low and midrange plasma vWF concentrations changed sharply, whereas the change between dogs with midrange and normal plasma vWF concentrations was gradual. Three matings between dogs with low vWF concentrations produced 13 offspring, all with low vWF concentrations. Two matings between dogs with normal plasma vWF concentrations produced 14 offspring, all with normal vWF concentrations. Eight matings between dogs with normal and low plasma vWF concentrations produced 54 offspring 40 with midrange, 13 with normal, and 1 with low vWF concentrations. There were 5 matings of dogs with midrange plasma vWF concentrations to dogs with low, midrange, or high vWF concentrations. The results of all matings were consistent with a single gene defect where each normal allele produced half the total amount of vWF when both alleles are normal and each defective allele produced < 15 U of vWF/dl.
Clinical Implications:
Dogs with low plasma vWF concentrations may be homozygous for the defective allele, whereas dogs with midrange plasma vWF concentrations may be heterozygous. It can be difficult to distinguish normal homozygotes from heterozygotes if evaluation is based only on plasma vWF concentration.