Non-mosaic X monosomy (77,X) in a female dog with signs of virilization

Abstract

A 14-month-old female Miniature Poodle dog with an enlarged clitoris and asymmetry in the placement of the teats was subjected to clinical, histopathological, and genetic studies. Macroscopically, the uterus and fallopian tubes appeared normal, while both ovaries were diffusely altered. At histology, the ovarian parenchyma was almost completely effaced by a diffuse hyperplasia of theca cells with atretic primary follicles. Chromosome analysis showed pure (non-mosaic) X monosomy (77,X). This finding was confirmed by the highly sensitive droplet digital PCR (ddPCR) approach. Despite the observed virilization, molecular analysis did not show the presence of Y-linked genes (SRY, ZFY, and TSPY1) in the blood cells or ovary tissue. To the best of our knowledge, this is the first case of X monosomy in a dog associated with virilization.

A rare finding of double Barr bodies and X‐monosomy/X‐trisomy mosaicism in a dog with presumed idiopathic epilepsy

“…While mosaicism is common in dogs with aneuploidies, 19 77,X/79,XXX mosaicism has never been reported in dogs and is infrequently reported in people. To date, Xmonosomy has been identified in only seven female dogs, 20,21 and X-trisomy has been reported in only six female dogs. 21 Of the six dogs affected by X-monosomy that had cytogenetic analysis, three were mosaic (77,X/78,XX) with a monosomic cell line frequency that ranged from 5% to 95%.…”