title: Evaluation of a test for identification of Arabian horses heterozygous for the severe combined immunodeficiency trait.
abstract: OBJECTIVE
  To determine whether a recently developed test would correctly identify horses heterozygous for the severe combined immunodeficiency (SCID) trait.
  
  
  METHODS
  Case series.
  
  
  METHODS
  17 healthy Arabian horses that had previously produced foals with SCID, 1 healthy Arabian foal whose dam and sire had produced foals with SCID, 4 foals with SCID, and 1 healthy non-Arabian foal.
  
  
  METHODS
  DNA was extracted from leukocytes or fibroblasts, amplified by means of polymerase chain reaction, and hybridized with probes specific for the normal and mutant alleles of the catalytic subunit of DNA-dependent protein kinase, the factor whose absence is responsible for SCID in Arabian foals.
  
  
  RESULTS
  Amplified DNA from the healthy non-Arabian foal hybridized only to the probe specific for the normal allele, whereas amplified DNA from the 4 foals with SCID hybridized only to the probe specific for the mutant allele. Amplified DNA from the 2 stallions and 15 mares hybridized with both probes, as did amplified DNA from the healthy foal whose dam and sire had previously produced foals with SCID, indicating that these horses were all heterozygous for the SCID trait.
  
  
  CONCLUSIONS
  Results suggest that the genetic test will be useful in identifying Arabian horses heterozygous for the SCID trait and foals with SCID, provided that all Arabian horses with SCID have the same genetic mutation.
authors.affiliation: Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235-8884, USA.
authors.forename: E K
authors.initials: EK
authors.lastname: Shin
authors.forename: L E
authors.initials: LE
authors.lastname: Perryman
authors.forename: K
authors.initials: K
authors.lastname: Meek
mesh_terms: D000483:Alleles; D000818:Animals; D001483:Base Sequence; D001947:Breeding; D004247:DNA / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D015342:DNA Probes / Q000235:genetics; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D005260:Female; D005347:Fibroblasts / Q000737:chemistry; D006580:Genetic Carrier Screening / Q000379:methods*; D005817:Genetic Counseling / Q000379:methods; D006579:Heterozygote; D006734:Horse Diseases / Q000175:diagnosis* / Q000209:etiology / Q000235:genetics*; D006736:Horses; D007962:Leukocytes / Q000737:chemistry; D008297:Male; D009154:Mutation; D009693:Nucleic Acid Hybridization; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary; D017346:Protein Serine-Threonine Kinases / Q000032:analysis / Q000235:genetics / Q000502:physiology; D016511:Severe Combined Immunodeficiency / Q000175:diagnosis / Q000235:genetics / Q000662:veterinary*
chemical_list: D015342:DNA Probes; D004268:DNA-Binding Proteins; D004247:DNA; D051747:DNA-Activated Protein Kinase; D017346:Protein Serine-Threonine Kinases