Structural abnormalities of the X-chromosome in a heifer.

Structural chromosome abnormalities, some of them unusual, were found in 18 (36%) of 50 photomicrographed mitotic cells of a blood lymphocyte culture from a three month old Holstein heifer affected with chronic tympanism of the rumen. The aberrations involved more specifically the X-chromosome. The etiology of the anomalies and the cause of their X-chromosome propension are of unknown nature.