Familial occurrence of diprosopus in German Holstein calves.

摘要

Diprosopus was diagnosed in 6 German Holstein calves born on different dairy farms. The degree of facial duplication varied from a partial doubling of the nostrils and upper jaw to complete duplication of the face with formation of 2 mouths, 4 eyes and 4 ears. Furthermore, calves descending from the same parents or dams and calves from the same farms were unaffected. A joint pedigree was ascertained for the calves with diprosopus. A previously reported case of diprosopus could be traced back to the same ancestors of this pedigree. Consequently, a familial accumulation of diprosopus was detected for the first time. Since the ancestors showed no signs of diprosopus and the frequency of diprosopus in German Holsteins was presumably low, an oligogenic inheritance was likely. Recessive genes or a combination of recessive and dominant genes might cause this anomaly..