Is a de novo nonsense variant in the ASPDH gene the cause of ulcerative skin lesions in a Holstein calf?

BACKGROUND: Genetic skin diseases in cattle are rare. CLINICAL SUMMARY: A 7-week-old female Holstein calf was presented with epidermal lesions and alopecia in the caudal region of the ears and on the neck, as well as deep bilateral ulcerative lesions on the palmar aspect of the metacarpi and dorsal aspect of the right metacarpus. Clinical, pathological and histopathological examination of the calf was suggestive of a subepidermal vesicular dermatosis. Genetic analysis identified a de novo non-sense variant affecting the aspartate dehydrogenase domain containing (ASPDH) gene, which might be associated with the formation of subepidermal vesicles in this case. CONCLUSION AND CLINICAL IMPORTANCE: The observed phenotype in the calf may represent a novel form of a vesicular skin disorder. Haploinsufficiency of the ASPDH gene might be considered as a possible cause.

APOB-associated cholesterol deficiency in Holstein cattle is not a simple recessive disease.

In 2015, cholesterol deficiency (CD) was reported for the first time as a new recessive defect in Holstein cattle. After GWAS mapping and identification of a disease-associated haplotype, a causative loss-of-function variant in APOB was identified. CD-clinically affected APOB homozygotes showed poor development, intermittent diarrhea and hypocholesterolemia and, consequently, a limited life expectation. Herein, we present a collection of 18 cases clinically diagnosed as CD-affected APOB heterozygotes. CD-clinically affected heterozygotes show reduced cholesterol and triglyceride blood concentrations. The differences in total blood cholesterol and triglycerides between nine CD-clinically affected and 36 non-affected heterozygotes were significant. As only some APOB heterozygotes show the clinical CD phenotype, we assume that the penetrance is reduced in heterozygotes compared to the fully penetrant effect observed in homozygotes. We conclude that APOB-associated CD represents most likely an incomplete dominant inherited metabolic disease with incomplete penetrance in heterozygotes.

Rumen perforation caused by horn injury in two cows.

Post-operative complications of trocarisation and rumenotomy are the most common causes of peritonitis associated with a rumen disorder. Since horn injury leading to rumen perforation has not previously been reported in the literature, two cows with this condition are reported. Small superficial skin lesions were observed in one of the cows and the other had a perforating skin lesion in the left abdomen. Both cows had signs of hypovolaemic shock. Ultrasonography revealed hypoechoic fluid, echoic lesions and occasional fibrinous septa caudoventral to the reticulum. Caudally the fluid extended to the left flank fold and occupied about one third of the peritoneal cavity. The area of the skin perforation in the left abdomen was swollen and the muscle layers could not be differentiated using ultrasonography. Diffuse fibrino-purulent peritonitis was diagnosed in both cows, and because of a poor prognosis, they were euthanased and necropsied. Perforation of the abdominal wall and rumen with diffuse fibrino-purulent peritonitis was present. Ultrasonography is a suitable tool to characterise the inflammatory lesions between the rumen and left abdominal wall and objectify the interpretation of clinical findings. Horn injury should be included in the rule outs for cattle with left abdominal skin wounds and diffuse peritonitis.