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Summary: 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. [ABSTRACT FROM AUTHOR]

Calves being stillborn is mostly reported to be due to infectious diseases, and the calves do not usually show obvious malformations.[1] However, congenital disorders owing to monogenic variation have been described, leading to a variety of severe skeletal malformations, e.g. chondrodysplasia (OMIA 000187-9913), including bulldog calf syndrome (OMIA 001926-9913) and arachnomelia (OMIA 000059-9913; OMIA 001541-9913). In particular, in the so-called Robertsonian translocation chromosome 29 fuses to chromosome 1.[11] However, as the increased read depth in chromosome 29 is clearly indicating a trisomy, we exclude the possibility of a translocation. In conclusion, we suspect that the trisomy of bovine chromosome 29 led to the lethal phenotype, including facial dysplasia in the stillborn calf. [Extracted from the article]