Veterinary Diagnostic Laboratory, Lansing, MI, USA.
Tibetan Terrier Health and Welfare Foundation, Sebastian, FL, USA.
J Vet Diagn Invest. 2021 Jul;33(4):740-743. doi: 10.1177/10406387211007526. Epub 2021 Apr 23.
Canine pituitary dwarfism in German Shepherd and related dog breeds has been reported to be associated with a 7-bp deletion mutation in intron 5 of the gene. This mutation is transmitted as an autosomal recessive trait that results in dwarf dogs with significantly smaller stature and abnormal haircoat, and potentially early death. Phenotypically, affected adult dogs are proportionally dwarfs. These dwarfs also have a soft, woolly puppy coat that fails to transition into the typical adult hair coat, and marked hair loss occurs in some dogs. We report a similar manifestation of dwarfism in Tibetan Terriers with the same mutation. Dwarf Tibetan Terrier puppies were born physically normal but failed to gain weight or to grow at the same rate as their normal littermates. The 7-bp deletion mutation of the gene was identified in both alleles of 3 Tibetan Terrier dwarfs from 3 litters, which were biologically related. All parents of these dogs are carriers, confirming transmission of dwarfism in an autosomal recessive manner. Recognition and detection of this mutation will help in guiding future breeding plans to eventually eliminate this trait from Tibetan Terriers.
犬垂体性侏儒症已在德国牧羊犬和相关犬种中被报道与基因 5 号内含子中的 7 碱基对缺失突变相关。这种突变作为常染色体隐性遗传特征遗传，导致矮小型犬具有明显较小的体型和异常的被毛，并可能导致早期死亡。表型上，受影响的成年犬呈比例性矮小。这些矮小型犬还具有柔软、羊毛状的幼犬被毛，无法过渡到典型的成年被毛，并且一些犬只发生明显的脱发。我们报告了具有相同突变的西藏梗犬中类似的侏儒症表现。侏儒型西藏梗幼犬出生时身体正常，但体重增加或生长速度与正常同窝幼犬不同。从 3 窝中 3 只具有生物学关系的侏儒型西藏梗犬的 2 个等位基因中鉴定出了 基因的 7 碱基对缺失突变。这些犬的所有父母均为携带者，证实了侏儒症以常染色体隐性方式遗传。识别和检测这种突变将有助于指导未来的繁殖计划，最终从西藏梗犬中消除这种特征。
