Open AccessPersistent Hyperammonemia in Two Related Morgan Weanlings
Author(s) -
McConnico Rebecca S.,
Duckett Wendy M.,
Wood Philip A.
Publication year - 1997
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/j.1939-1676.1997.tb00101.x
Subject(s) - hyperammonemia , medicine , urea cycle , orotic acid , liver biopsy , ornithine , endocrinology , hepatic encephalopathy , biopsy , amino acid , biochemistry , biology , cirrhosis , arginine
Persistent hyperammonemia was diagnosed in 2 Morgan fillies with clinical signs that developed early in the post‐weaning period. Diagnostic evaluation, including routine serum chemistries, CBC, liver biopsy, hepatic ultrasonography, liver function test, and necropsy findings did not support a toxic, developmental, or infectious cause. Abnormal serum amino acid and urine orotic acid concentrations suggest that the foals may have had an inherited disorder, described in humans as hyperornithinemia, hyperammonemia, and homocitrullinuria (HHH) syndrome. The disorder is thought to be caused by a defective mitochondrial transporter protein, such that ornithine, required for complete urea synthesis, is deficient, thus causing increases in blood ammonia and ornithine concentrations.