A 50-kb deletion disrupting the RSPO2 gene is associated with tetradysmelia in Holstein Friesian cattle

Abstract Background Tetradysmelia is a rare genetic disorder that is characterized by an extremely severe reduction of all limb parts distal of the scapula and pelvic girdle. We studied a Holstein Friesian backcross family with 24 offspring, among which six calves displayed autosomal recessive tetradysmelia. In order to identify the genetic basis of the disorder, we genotyped three affected calves, five dams and nine unaffected siblings using a Bovine Illumina 50 k BeadChip and sequenced the whole genome of the sire. Results Pathological examination of four tetradysmelia cases revealed a uniform and severe dysmelia of all limbs. Applying a homozygosity mapping approach, we identified a homozygous region of 10.54 Mb on chromosome 14 (Bos taurus BTA14). Only calves that were diagnosed with tetradysmelia shared a distinct homozygous haplotype for this region. We sequenced the whole genome of the cases’ sire and searched for heterozygous single nucleotide polymorphisms (SNPs) and small variants on BTA14 that were uniquely present in the sire and absent from 3102 control whole-genome sequences of the 1000 Bull Genomes Project, but none were identified in the 10.54-Mb candidate region on BTA14. Therefore, we subsequently performed a more comprehensive analysis by also considering structural variants and detected a 50-kb deletion in the targeted chromosomal region that was in the heterozygous state in the cases’ sire. Using PCR, we confirmed that this detected deletion segregated perfectly within the family with tetradysmelia. The deletion spanned three exons of the bovine R-spondin 2 (RSPO2) gene, which encode three domains of the respective protein. R-spondin 2 is a secreted ligand of leucine-rich repeats containing G protein-coupled receptors that enhance Wnt signalling and is involved in a broad range of developmental processes during embryogenesis. Conclusions We identified a 50-kb deletion on BTA14 that disrupts the coding sequence of the RSPO2 gene and is associated with bovine tetradysmelia. To our knowledge, this is the first reported candidate causal mutation for tetradysmelia in a large animal model. Since signalling pathways involved in limb development are conserved across species, the observed inherited defect may serve as a model to further elucidate fundamental pathways of limb development.

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A Nonsense Variant in Hephaestin Like 1 (HEPHL1) Is Responsible for Congenital Hypotrichosis in Belted Galloway Cattle

Genes ◽

10.3390/genes12050643 ◽

2021 ◽

Vol 12 (5) ◽

pp. 643

Author(s):

Thibaud Kuca ◽

Brandy M. Marron ◽

Joana G. P. Jacinto ◽

Julia M. Paris ◽

Christian Gerspach ◽

...

Keyword(s):

Genome Wide Association Study ◽

Homozygosity Mapping ◽

Mendelian Inheritance ◽

Large Animal Model ◽

Large Animal ◽

Loss Of Function ◽

Protein Coding ◽

Positional Candidate ◽

Genome Wide ◽

A Genome

Genodermatosis such as hair disorders mostly follow a monogenic mode of inheritance. Congenital hypotrichosis (HY) belong to this group of disorders and is characterized by abnormally reduced hair since birth. The purpose of this study was to characterize the clinical phenotype of a breed-specific non-syndromic form of HY in Belted Galloway cattle and to identify the causative genetic variant for this recessive disorder. An affected calf born in Switzerland presented with multiple small to large areas of alopecia on the limbs and on the dorsal part of the head, neck, and back. A genome-wide association study using Swiss and US Belted Galloway cattle encompassing 12 cases and 61 controls revealed an association signal on chromosome 29. Homozygosity mapping in a subset of cases refined the HY locus to a 1.5 Mb critical interval and subsequent Sanger sequencing of protein-coding exons of positional candidate genes revealed a stop gain variant in the HEPHL1 gene that encodes a multi-copper ferroxidase protein so-called hephaestin like 1 (c.1684A>T; p.Lys562*). A perfect concordance between the homozygous presence of this most likely pathogenic loss-of-function variant and the HY phenotype was found. Genotyping of more than 700 purebred Swiss and US Belted Galloway cattle showed the global spread of the mutation. This study provides a molecular test that will permit the avoidance of risk matings by systematic genotyping of relevant breeding animals. This rare recessive HEPHL1-related form of hypotrichosis provides a novel large animal model for similar human conditions. The results have been incorporated in the Online Mendelian Inheritance in Animals (OMIA) database (OMIA 002230-9913).

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Missense variant in LOXHD1 is associated with canine nonsyndromic hearing loss

Human Genetics ◽

10.1007/s00439-021-02286-z ◽

2021 ◽

Author(s):

Marjo K. Hytönen ◽

Julia E. Niskanen ◽

Meharji Arumilli ◽

Casey A. Brookhart-Knox ◽

Jonas Donner ◽

...

Keyword(s):

Hearing Loss ◽

Cell Function ◽

Autosomal Recessive Inheritance ◽

Missense Variant ◽

Homozygosity Mapping ◽

Large Animal Model ◽

Large Animal ◽

Hearing Disorder ◽

Nonsyndromic Hearing Loss ◽

Cochlear Hair Cell

AbstractHearing loss is a common sensory deficit in both humans and dogs. In canines, the genetic basis is largely unknown, as genetic variants have only been identified for a syndromic form of hearing impairment. We observed a congenital or early-onset sensorineural hearing loss in a Rottweiler litter. Assuming an autosomal recessive inheritance, we used a combined approach of homozygosity mapping and genome sequencing to dissect the genetic background of the disorder. We identified a fully segregating missense variant in LOXHD1, a gene that is known to be essential for cochlear hair cell function and associated with nonsyndromic hearing loss in humans and mice. The canine LOXHD1 variant was specific to the Rottweiler breed in our study cohorts of pure-bred dogs. However, it also was present in some mixed-breed dogs, of which the majority showed Rottweiler ancestry. Low allele frequencies in these populations, 2.6% and 0.04%, indicate a rare variant. To summarize, our study describes the first genetic variant for canine nonsyndromic hearing loss, which is clinically and genetically similar to human LOXHD1-related hearing disorder, and therefore, provides a new large animal model for hearing loss. Equally important, the affected breed will benefit from a genetic test to eradicate this LOXHD1-related hearing disorder from the population.

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Associations between novel single nucleotide polymorphisms in the Bos taurus growth hormone gene and performance traits in Holstein-Friesian dairy cattle

Journal of Dairy Science ◽

10.3168/jds.2010-3385 ◽

2010 ◽

Vol 93 (12) ◽

pp. 5959-5969 ◽

Cited By ~ 22

Author(s):

M.P. Mullen ◽

D.P. Berry ◽

D.J. Howard ◽

M.G. Diskin ◽

C.O. Lynch ◽

...

Keyword(s):

Growth Hormone ◽

Single Nucleotide Polymorphisms ◽

Dairy Cattle ◽

Bos Taurus ◽

Growth Hormone Gene ◽

Nucleotide Polymorphisms ◽

Single Nucleotide ◽

Holstein Friesian ◽

Performance Traits ◽

And Performance

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Missense Variant in LOXHD1 is Associated With Canine Nonsyndromic Hearing Loss

10.21203/rs.3.rs-288479/v1 ◽

2021 ◽

Author(s):

Marjo K Hytönen ◽

Julia E Niskanen ◽

Meharji Arumilli ◽

Casey A Knox ◽

Jonas Donner ◽

...

Keyword(s):

Hearing Loss ◽

Cell Function ◽

Autosomal Recessive Inheritance ◽

Missense Variant ◽

Homozygosity Mapping ◽

Large Animal Model ◽

Large Animal ◽

Hearing Disorder ◽

Nonsyndromic Hearing Loss ◽

Cochlear Hair Cell

Abstract Hearing loss is a common sensory deficit both in humans and dogs. In canines the genetic basis is largely unknown, as genetic variants have only been identified for a syndromic form of hearing impairment. We observed a congenital or early-onset sensorineural hearing loss in a Rottweiler litter. Assuming an autosomal recessive inheritance, we used a combined approach of homozygosity mapping and genome sequencing to dissect the genetic background of the disorder. We identified a fully segregating missense variant in LOXHD1, a gene that is known to be essential for cochlear hair cell function and associated with nonsyndromic hearing loss in humans and mice. The canine LOXHD1 variant was specific to the Rottweiler breed in our study cohorts of pure-bred dogs. However, it also was present in mixed-breed dogs, of which the majority showed Rottweiler ancestry. Low allele frequencies in these populations, 2.6 % and 0.04 %, respectively, indicate a rare variant. To summarize, our study describes the first genetic variant for canine nonsyndromic hearing loss, which is clinically and genetically similar to human LOXHD1-related hearing disorder, and therefore, provides a new large animal model for hearing loss. Equally important, the affected breed will benefit from a genetic test to eradicate the hearing disorder from the population.

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