Werewolf, There Wolf: Variants in Hairless Associated with Hypotrichia and Roaning in the Lykoi Cat Breed.

A variety of cat breeds have been developed via novelty selection on aesthetic, dermatological traits, such as coat colors and fur types. A recently developed breed, the lykoi (a.k.a. werewolf cat), was bred from cats with a sparse hair coat with roaning, implying full color and all white hairs. The lykoi phenotype is a form of hypotrichia, presenting as a significant reduction in the average numbers of follicles per hair follicle group as compared to domestic shorthair cats, a mild to severe perifollicular to mural lymphocytic infiltration in 77% of observed hair follicle groups, and the follicles are often miniaturized, dilated, and dysplastic. Whole genome sequencing was conducted on a single lykoi cat that was a cross between two independently ascertained lineages. Comparison to the 99 Lives dataset of 194 non-lykoi cats suggested two variants in the cat homolog for Hairless (HR) (HR lysine demethylase and nuclear receptor corepressor) as candidate causal gene variants. The lykoi cat was a compound heterozygote for two loss of function variants in HR, an exon 3 c.1255_1256dupGT (chrB1:36040783), which should produce a stop codon at amino acid 420 (p.Gln420Serfs*100) and, an exon 18 c.3389insGACA (chrB1:36051555), which should produce a stop codon at amino acid position 1130 (p.Ser1130Argfs*29). Ascertainment of 14 additional cats from founder lineages from Canada, France and different areas of the USA identified four additional loss of function HR variants likely causing the highly similar phenotypic hair coat across the diverse cats. The novel variants in HR for cat hypotrichia can now be established between minor differences in the phenotypic presentations.

Exercise-induced hyperthermia syndrome (canine stress syndrome) in four related male English springer spaniels.

OBJECTIVE: This retrospective study describes the signalment, clinical presentation, diagnostic findings, and mode of inheritance in four young male English springer spaniel dogs with presumptive canine stress syndrome. MATERIALS AND METHODS: Appropriate cases were located through medical searches of medical records of two large private referral centers. Inclusion criteria comprised of English springer spaniel dogs with tachypnea and hyperthermia that subsequently developed weakness or collapse, with or without signs of hemorrhage, soon after a period of mild-to-moderate exercise. The pedigrees of the four affected dogs, as well as eleven related English springer spaniels, were then analyzed to determine a presumptive mode of genetic inheritance. RESULTS: Four dogs met the inclusion criteria. All four were male, suggesting the possibility of a recessive sex-linked heritable disorder. Pedigree analysis suggests that more dogs may be potentially affected, although these dogs may have never had the concurrent triggering drug/activity/event to precipitate the clinical syndrome. There was complete resolution of clinical signs in three of the four dogs with aggressive symptomatic and supportive therapy, with one dog dying during treatment. CONCLUSION: Dogs with canine stress syndrome have the potential for rapid recovery if treated aggressively and the complications of the disease (eg, coagulopathy) are anticipated. All four dogs were male, suggesting the possibility of a recessive sex-linked mode of inheritance. Further genetic analyses should be strongly considered by those involved with the English springer spaniel breed, either with a genome-wide association study using canine single-nucleotide polymorphism arrays or whole-genome sequencing of affected and closely related dogs.

A FAS-ligand variant associated with autoimmune lymphoproliferative syndrome in cats.

British shorthair (BSH) kittens in multiple litters died as a result of a severe non-neoplastic lymphoproliferative disease that showed many similarities with human autoimmune lymphoproliferative syndrome (ALPS). Human ALPS is caused by inherited defects in FAS-mediated lymphocyte apoptosis and the possibility of similar defects was investigated in BSH cats. The whole genomes of two affected kittens were sequenced and compared to 82 existing cat genomes. Both BSH kittens had homozygous insertions of an adenine within exon 3 of the FAS-ligand gene. The resultant frameshift and premature stop codon were predicted to result in a severely truncated protein that is unlikely to be able to activate FAS. Three additional affected BSH kittens were homozygous for the variant, while 11 of 16 unaffected, but closely related, BSH cats were heterozygous for the variant. All BSH cats in the study were from a population with significant inbreeding. The variant was not identified in a further survey of 510 non-BSH cats. Identification of a genetic defect in the FAS-mediated apoptosis pathway confirms that the lymphoproliferative disease in BSH cats fulfills the diagnostic criteria for ALPS in humans. These results will enable the development of a genetic test to detect BSH carrier animals.

A One Health overview, facilitating advances in comparative medicine and translational research.

TABLE OF CONTENTS: A1 One health advances and successes in comparative medicine and translational researchCheryl StroudA2 Dendritic cell-targeted gorilla adenoviral vector for cancer vaccination for canine melanomaIgor Dmitriev, Elena Kashentseva, Jeffrey N. Bryan, David T. CurielA3 Viroimmunotherapy for malignant melanoma in the companion dog modelJeffrey N. Bryan, David Curiel, Igor Dmitriev, Elena Kashentseva, Hans Rindt, Carol Reinero, Carolyn J. HenryA4 Of mice and men (and dogs!): development of a commercially licensed xenogeneic DNA vaccine for companion animals with malignant melanomaPhilip J. BergmanA5 Successful immunotherapy with a recombinant HER2-expressing Listeria monocytogenes in dogs with spontaneous osteosarcoma paves the way for advances in pediatric osteosarcomaNicola J. Mason, Josephine S. Gnanandarajah, Julie B. Engiles, Falon Gray, Danielle Laughlin, Anita Gaurnier-Hausser, Anu Wallecha, Margie Huebner, Yvonne PatersonA6 Human clinical development of ADXS-HER2Daniel O'ConnorA7 Leveraging use of data for both human and veterinary benefitLaura S. TremlA8 Biologic replacement of the knee: innovations and early clinical resultsJames P. StannardA9 Mizzou BioJoint Center: a translational success storyJames L. CookA10 University and industry translational partnership: from the lab to commercializationMarc JacobsA11 Beyond docking: an evolutionarily guided OneHealth approach to drug discoveryGerald J. Wyckoff, Lee Likins, Ubadah Sabbagh, Andrew SkaffA12 Challenges and opportunities for data applications in animal health: from precision medicine to precision husbandryAmado S. GuloyA13 A cloud-based programmable platform for healthHarlen D. HaysA14 Comparative oncology: One Health in actionAmy K. LeBlancA15 Companion animal diseases bridge the translational gap for human neurodegenerative diseaseJoan R. Coates, Martin L. Katz, Leslie A. Lyons, Gayle C. Johnson, Gary S. Johnson, Dennis P. O'BrienA16 Duchenne muscular dystrophy gene therapyDongsheng DuanA17 Polycystic kidney disease: cellular mechanisms to emerging therapiesJames P. CalvetA18 The domestic cat as a large animal model for polycystic kidney diseaseLeslie A. Lyons, Barbara GandolfiA19 The support of basic and clinical research by the Polycystic Kidney Disease FoundationDavid A. BaronA20 Using naturally occurring large animal models of human disease to enable clinical translation: treatment of arthritis using autologous stromal vascular fraction in dogsMark L. WeissA21 Regulatory requirements regarding clinical use of human cells, tissues, and tissue-based productsDebra A. WebsterA22 Regenerative medicine approaches to Type 1 diabetes treatmentFrancis N. KaranuA23 The zoobiquity of canine diabetes mellitus, man's best friend is a friend indeed-islet transplantationEdward J. RobbA24 One Medicine: a development model for cellular therapy of diabetesRobert J. Harman.

Aristaless-Like Homeobox protein 1 (ALX1) variant associated with craniofacial structure and frontonasal dysplasia in Burmese cats.

Frontonasal dysplasia (FND) can have severe presentations that are medically and socially debilitating. Several genes are implicated in FND conditions, including Aristaless-Like Homeobox 1 (ALX1), which is associated with FND3. Breeds of cats are selected and bred for extremes in craniofacial morphologies. In particular, a lineage of Burmese cats with severe brachycephyla is extremely popular and is termed Contemporary Burmese. Genetic studies demonstrated that the brachycephyla of the Contemporary Burmese is a simple co-dominant trait, however, the homozygous cats have a severe craniofacial defect that is incompatible with life. The craniofacial defect of the Burmese was genetically analyzed over a 20 year period, using various genetic analysis techniques. Family-based linkage analysis localized the trait to cat chromosome B4. Genome-wide association studies and other genetic analyses of SNP data refined a critical region. Sequence analysis identified a 12bp in frame deletion in ALX1, c.496delCTCTCAGGACTG, which is 100% concordant with the craniofacial defect and not found in cats not related to the Contemporary Burmese.

Hspb1 and Tp53 Mutation and Expression Analysis in Cat Mammary Tumors.

BACKGROUND: Molecular marker based cancer diagnosis gaining more attention in the current genomics era. So, Hspb1 and Tp53 gene characterization and their mRNA expression might be helpful in diagnosis and prognosis of cat mammary adenocarcinoma. It will also add information in comparative cancer genetics and genomics. OBJECTIVES: Eight tumors of Siamese cats were analyzed to ascertain germ-line and tissue-specific somatic DNA variations of Hspb1 and Tp53 genes along with the ectopic differential expression in tumorous and normal tissues were also analyzed. MATERIALS AND METHODS: Tumorous tissues and peripheral blood from mammary adenocarcinoma affected Siamese cats were collected from the Pet center-UVAS. DNA and RNA were extracted from these tissues to analyze the Hspb1 and Tp53 DNA variants and ectopic expression of their mRNA within cancerous and normal tissues. RESULTS: Exon 1 and 3 revealed as hotspots in Hspb1 gene. The 5´UTR region of the exon1 bear six mutation including 3 transitions, 2 transversion and one heterozygous synonymous transversion in two samples at locus c.34C>C/A. Exon 3 has 1 transversion at c.773A>A/T, 3´UTR of this exon harbor two point mutations at 1868A>T and 2193C>T loci. Intron 2 has two alterations at 1490C>C/T and GTCT4del at 1514. Overall up-regulation of Hspb1 gene was observed. While exons 3, 4 and 7 of Tp53 harbor a single variationat c.105A>A/G, c.465T>T/C and c.859G>T respectively. The locus c.1050G>G/A in exon 9 is a heterozygous (G/A) in 3 samples and homozygous (G) in 2 other tumours. Introns 3, 5, 7 and 9 harbor 3, 4, 2 and 7 altered loci respectively. Sixty percent of cancers showed up-regulated trend of Tp53 gene. CONCLUSIONS: Tumor specific mutations and ectopic expression of Hspb1 and Tp53 genes might be helpful in the diagnosis of the mammary lesions and endorse their involvement in cat mammary neoplasm.

COLQ variant associated with Devon Rex and Sphynx feline hereditary myopathy.

Some Devon Rex and Sphynx cats have a variably progressive myopathy characterized by appendicular and axial muscle weakness, megaesophagus, pharyngeal weakness and fatigability with exercise. Muscle biopsies from affected cats demonstrated variable pathological changes ranging from dystrophic features to minimal abnormalities. Affected cats have exacerbation of weakness following anticholinesterase dosing, a clue that there is an underlying congenital myasthenic syndrome (CMS). A genome-wide association study and whole-genome sequencing suggested a causal variant for this entity was a c.1190G>A variant causing a cysteine to tyrosine substitution (p.Cys397Tyr) within the C-terminal domain of collagen-like tail subunit (single strand of homotrimer) of asymmetric acetylcholinesterase (COLQ). Alpha-dystroglycan expression, which is associated with COLQ anchorage at the motor end-plate, has been shown to be deficient in affected cats. Eighteen affected cats were identified by genotyping, including cats from the original clinical descriptions in 1993 and subsequent publications. Eight Devon Rex and one Sphynx not associated with the study were identified as carriers, suggesting an allele frequency of ~2.0% in Devon Rex. Over 350 tested cats from other breeds did not have the variant. Characteristic clinical features and variant presence in all affected cats suggest a model for COLQ CMS. The association between the COLQ variant and this CMS affords clinicians the opportunity to confirm diagnosis via genetic testing and permits owners and breeders to identify carriers in the population. Moreover, accurate diagnosis increases available therapeutic options for affected cats based on an understanding of the pathophysiology and experience from human CMS associated with COLQ variants.

Investigation of inherited diseases in cats: genetic and genomic strategies over three decades.

PRACTICAL RELEVANCE: The health of the cat mirrors a complex interaction between its environment (nurture) and its genetics (nature). To date, over 70 genetic mutations (variants) have been defined in the cat; many involve diseases, structural anomalies, coat color and texture, including numerous that are clinically relevant. This trend will continue as more of the feline genome is deciphered. Genetic testing, and eventually whole-genome sequencing, should become routine diagnostic tools in feline healthcare within the foreseeable future. GLOBAL IMPORTANCE: Cat breeds have dispersed around the world. Thus, feline medicine clinicians should be aware of breeds common to their region and common mutations found within those regional populations. Random-bred populations of domestic cats can also have defined genetic characteristics and mutations, which are equally worthy of understanding by feline medicine clinicians. OUTLINE: This article reviews the chronology and evolution of genetic and genomic tools pertinent to feline medicine. Possible strategies for mapping genetic traits and defects, and how these impact on feline health, are also discussed. The focus is on three historical periods: (1) research conducted before the availability of the cat genome; (2) research performed immediately after the availability of sequences of the cat genome; and (3) current research that goes beyond one cat genome and utilizes the genome sequences of many cats. EVIDENCE BASE: The data presented are extracted from peer-reviewed publications pertaining to mutation identification, and relevant articles concerning heritable traits and/or diseases. The authors draw upon their personal experience and expertise in feline genetics.

Periodic hypokalaemic polymyopathy in Burmese and closely related cats: a review including the latest genetic data.

GLOBAL IMPORTANCE: Hypokalaemic polymyopathy is a genetic disease of Burmese cats that has been encountered in Australasia, Europe and South Africa. CLINICAL FEATURES: Affected cats usually present with signs of muscle weakness and muscle pain in the first year of life. Although certain clinical features, such as ventroflexion of the head and neck, are especially characteristic, some cats do not display these signs. Usually weakness is periodic or episodic, but occasionally it is incessant. DIAGNOSTIC CHALLENGES: In the past, diagnosis was problematic in that clinical signs and a lowered serum potassium concentration were not always observed synchronously. This necessitated serial serum potassium concentration determinations, testing of serum creatine kinase activity and exclusion of other potential causes of muscle disease in cats (including muscular dystrophies, Toxoplasma myositis, immune-mediated polymyositis, organophosphorus intoxication and envenomations). Signs in affected cats often waxed and waned, possibly in response to changes in dietary factors and stress, and some cats could apparently 'grow out of' the condition. RECENT ADVANCES AND FUTURE PROSPECTS: Recent molecular genetics research has identified a single nonsense mutation in the gene (WNK4) coding for lysine-deficient 4 protein kinase, an enzyme present primarily in the distal nephron. The underlying pathomechanism in affected cats is therefore likely to be a potassium wasting nephropathy, as this enzyme is involved in complex sodium/potassium exchange mechanisms in the kidney. Additional functional characterisation of the condition is warranted to define precisely how, why and when the serum potassium concentration declines. The diagnosis of Burmese hypokalaemia is now straightforward, as an inexpensive PCR test can identify affected homozygous individuals, as well as carriers. The elimination of this condition from the Burmese breed, and also from pedigree cats infused with Burmese lines, such as the Bombay, Tonkinese and Tiffanie breeds, should therefore be possible.

A novel mutation in CLCN1 associated with feline myotonia congenita.

Myotonia congenita (MC) is a skeletal muscle channelopathy characterized by inability of the muscle to relax following voluntary contraction. Worldwide population prevalence in humans is 1:100,000. Studies in mice, dogs, humans and goats confirmed myotonia associated with functional defects in chloride channels and mutations in a skeletal muscle chloride channel (CLCN1). CLCN1 encodes for the most abundant chloride channel in the skeletal muscle cell membrane. Five random bred cats from Winnipeg, Canada with MC were examined. All cats had a protruding tongue, limited range of jaw motion and drooling with prominent neck and proximal limb musculature. All cats had blepharospasm upon palpebral reflex testing and a short-strided gait. Electromyograms demonstrated myotonic discharges at a mean frequency of 300 Hz resembling the sound of a 'swarm of bees'. Muscle histopathology showed hypertrophy of all fiber types. Direct sequencing of CLCN1 revealed a mutation disrupting a donor splice site downstream of exon 16 in only the affected cats. In vitro translation of the mutated protein predicted a premature truncation and partial lack of the highly conserved CBS1 (cystathionine ß-synthase) domain critical for ion transport activity and one dimerization domain pivotal in channel formation. Genetic screening of the Winnipeg random bred population of the cats' origin identified carriers of the mutation. A genetic test for population screening is now available and carrier cats from the feral population can be identified.

First WNK4-hypokalemia animal model identified by genome-wide association in Burmese cats.

Burmese is an old and popular cat breed, however, several health concerns, such as hypokalemia and a craniofacial defect, are prevalent, endangering the general health of the breed. Hypokalemia, a subnormal serum potassium ion concentration ([K(+)]), most often occurs as a secondary problem but can occur as a primary problem, such as hypokalaemic periodic paralysis in humans, and as feline hypokalaemic periodic polymyopathy primarily in Burmese. The most characteristic clinical sign of hypokalemia in Burmese is a skeletal muscle weakness that is frequently episodic in nature, either generalized, or sometimes localized to the cervical and thoracic limb girdle muscles. Burmese hypokalemia is suspected to be a single locus autosomal recessive trait. A genome wide case-control study using the illumina Infinium Feline 63K iSelect DNA array was performed using 35 cases and 25 controls from the Burmese breed that identified a locus on chromosome E1 associated with hypokalemia. Within approximately 1.2 Mb of the highest associated SNP, two candidate genes were identified, KCNH4 and WNK4. Direct sequencing of the genes revealed a nonsense mutation, producing a premature stop codon within WNK4 (c.2899C>T), leading to a truncated protein that lacks the C-terminal coiled-coil domain and the highly conserved Akt1/SGK phosphorylation site. All cases were homozygous for the mutation. Although the exact mechanism causing hypokalemia has not been determined, extrapolation from the homologous human and mouse genes suggests the mechanism may involve a potassium-losing nephropathy. A genetic test to screen for the genetic defect within the active breeding population has been developed, which should lead to eradication of the mutation and improved general health within the breed. Moreover, the identified mutation may help clarify the role of the protein in K⁺ regulation and the cat represents the first animal model for WNK4-associated hypokalemia.

Scintigraphic, neuroradiological and clinical comparison in two patients with primary sporadic and two with secondary Fahr's disease.

Bilateral striopallidodentate calcification, usually termed Fahr's disease, can give rise to various clinical manifestations including hyperkinetic movement disorders or a hypokinetic Parkinsonian syndrome, behavioural and mood changes, cognitive deficits and even frank dementia. We describe four patients all of whom underwent a detailed scintigraphic, neuroradiological and clinical work-up: two had primary, sporadic Fahr's disease and two had Fahr's disease secondary to hypoparathyroidism. The neuroradiological and clinical studies disclosed similar anatomical and pathological changes in the four patients but variable and sometimes unexpected clinical manifestations. Both patients with primary forms had hypokinetic Parkinsonian syndrome, both patients with secondary forms had hyperkinetic movements. Dopamine autotransporter scan brain scintigraphy disclosed an unexpected unilateral putamen involvement despite substantially symmetric calcifications.