title: Skin malformations in a neonatal foal tested homozygous positive for Warmblood Fragile Foal Syndrome.
abstract: BACKGROUND
  Skin malformations that resembled manifestations of Ehlers-Danlos-Syndrome were described in a variety of domestic animals during the last century as cutis hyperelastica, hyperelastosis cutis, dermatosparaxis, dermal/collagen dysplasia, dermal/cutaneous asthenia or Ehlers-Danlos-like syndrome/s. In 2007, the mutation responsible for Hereditary Equine Regional Dermal Asthenia (HERDA) in Quarter Horses was discovered. Several case reports are available for similar malformations in other breeds than Quarter Horses (Draught Horses, Arabians, and Thoroughbreds) including four case reports for Warmblood horses. Since 2013, a genetic test for the Warmblood Fragile Foal Syndrome Type 1 (WFFS), interrogating the causative point mutation in the equine procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1, or lysyl hydroxylase 1) gene, has become available. Only limited data are available on the occurrence rate and clinical characteristics of this newly detected genetic disease in horses. In humans mutations in this gene are associated with Ehlers-Danlos Syndrome Type VI (kyphoscoliotic form).
  
  
  METHODS
  This is the first report describing the clinical and histopathological findings in a foal confirmed to be homozygous positive for WFFS. The Warmblood filly was born with very thin, friable skin, skin lesions on the legs and the head, and an open abdomen. These abnormalities required euthanasia just after delivery. Histologic examination revealed abnormally thin dermis, markedly reduced amounts of dermal collagen bundles, with loosely orientation and abnormally large spaces between deep dermal fibers.
  
  
  CONCLUSIONS
  WFFS is a novel genetic disease in horses and should be considered in cases of abortion, stillbirth, skin lesions and malformations of the skin in neonatal foals. Genetic testing of suspicious cases will contribute to evaluate the frequency of occurrence of clinical WFFS cases and its relevance for the horse population.
authors: Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. cmonthoux@vetclinics.uzh.ch.
authors: Chloé
authors: C
authors: Monthoux
authors: Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. simone.debrot@nottingham.ac.uk.|Current address: School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, LE12 5RD, UK. simone.debrot@nottingham.ac.uk.
authors: Simone
authors: S
authors: de Brot
authors: Equine Department, Section Surgery, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. mjackson@vetclinics.uzh.ch.
authors: Michelle
authors: M
authors: Jackson
authors: Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. ubleul@vetclinics.uzh.ch.
authors: Ulrich
authors: U
authors: Bleul
authors: Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland. jwalter@vetclinics.uzh.ch.
authors: Jasmin
authors: J
authors: Walter
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000235:genetics; D004535:Ehlers-Danlos Syndrome / Q000235:genetics / Q000473:pathology / Q000662:veterinary*; D005260:Female; D006720:Homozygote; D006734:Horse Diseases / Q000235:genetics / Q000473:pathology*; D006736:Horses / Q000235:genetics; D010375:Pedigree; D012867:Skin / Q000473:pathology*
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