A de novo mutation in KRT5 in a crossbred calf with epidermolysis bullosa simplex

A 6-day-old Belgian Blue-Holstein calf was referred because of a syndrome resembling epidermolysis bullosa simplex (EBS). The clinical phenotype included irregular and differently sized erosions and ulcerations spread over the body, in particular on the limbs and over bone prominences, as well as in the nasal planum and oral mucosa. Blisters were easily induced by rubbing the skin. The skin lesions displayed a clear dermal-epidermal separation at the level of the basal cell layer. Post mortem examination revealed erosions in the pharynx, proximal esophagus, and rumen. Whole-genome sequencing revealed a heterozygous disruptive in-frame deletion variant in KRT5 (c.534_536delCAA). Genotyping of both parents confirmed the variant as de novo mutation. Clinicopathological and genetic findings were consistent with the diagnosis of KRT5-related EBS providing the second example of a spontaneous mutation causing epidermolysis bullosa in cattle

Perosomus Elumbis in calves

This report presents the most important clinical and morphological aspects of the so-called \u201cPerosomus Elumbis\u201d, a congenital vertebral malformation of calves characterized by the segmental lack of vertebrae caudal to the thoracic spine. The etiology has to be defined, but inheritance is suspected. The report is based on seven calves (five Holstein, one Brown and 1 cross breed) examined at the Veterinary Clinical Department of the University of Bologna (BO66/04; BO107/04; BO46/06; BO107/06; BO290/08) or at the Department of Veterinary Clinical Sciences of Padua (PD34/04; PD66/04). All animals appeared bright and alert at birth, but were completely unable to stand up or to maintain quadrupedal stance if raised manually. The seven calves, ranging from one to 15 days of age, were euthanized on the first day of hospitalization. Although having individual clinical presentation, the disorder was morphologically characterized by partial or complete segmental absence of vertebra, mostly of the lumbar and sacral segments. The tail was always missing. As a consequence of the vertebral malformation, the animals\u2019 trunks were shorter than normal, and the posterior part of the body was clearly underdeveloped. More precisely, the girdle showed a reduction in size and width whereas the hind limbs were shorter with evident muscular hypoplasia. In some cases, due to the lack of vertebrae, the hind limbs were attached to the caudal aspect of the thorax by soft tissue only. On the contrary, the anterior half of the body - from the caudal part of the thorax - was normal. Radiological examination clearly demonstrated the skeletal malformation including the lack of vertebrae. Internal organ malformations, such as intestinal atresia, hydronephrosis, testicular agenesia, uterine and vaginal malformations as well as concentric cardiac hypertrophy were also observed in some animals. In the context of general scientific interest in genetic diseases of cattle, the Authors suspect Perosomus Elumbis to be a potential inherited disease. However, the reported cases studies did not provide evidence for this hypothesis. Identification of clinical cases and reports of malformed calves are necessary to improve the knowledge of this defect