Abstract Proceedings EROC 2011 - New York Osteopathic Medical ...

EROC 2011 Abstract Proceedings – March 4, 2011
Dept. of Pediatrics, Good Samaritan Hospital Medical Center, West Islip, NY
Title: Rare Presentation of Undiagnosed Arginase Deficiency
Authors: Stanley Phillips, D.O. (1) David Gold, M.D. (2)
(1) Department of Medical Education, (2) Department of Pediatrics Division of Pediatric
Gastroenterology, Good Samaritan Hospital Medical Center, West Islip, New York
Introduction: Arginase deficiency is a rare autosomal recessive disorder caused by (a)
mutation(s) in the ARG1 gene on chromosome 6q23. It usually becomes symptomatic by early
childhood with the first symptoms being neurologic. A favorable outcome can be expected with
appropriate treatment. If untreated, symptoms are progressive with plateauing in cognitive
development and subsequent loss of developmental milestones.
Case Description: An 18-year-old male with mental retardation, cerebral palsy, seizure disorder
and global developmental delay that began in early childhood presented to the ER with a 3-day
history of right knee swelling. It was not associated with trauma, pain or recent infection.
Physical examination revealed mild swelling of the right knee without erythema or warmth and a
mildly distended abdomen without organomegaly. Laboratory findings demonstrated
pancytopenia, prolonged prothrombin time unresponsive to vitamin K, elevated transaminases,
normal bilirubin and hypoalbuminemia. Imagining of the lower extremities revealed no fracture,
but diffuse osteoporosis. Doppler ultrasound showed no evidence of deep venous thrombosis.
Abdominal ultrasound revealed splenomegaly, ascites, and a small, echogenic liver suggestive of
cirrhosis. Cirrhosis was confirmed by liver biopsy. Further testing revealed an elevated
ammonia level of 95. Plasma amino acids showed an elevated arginine level and a diagnosis of
arginase deficiency was made. Treatment was initiated using sodium phenylbutyrate and a low
protein diet with supplementation of essential amino acids.
Discussion: This case demonstrates portal hypertension and cirrhosis in a neurologically
impaired child with undiagnosed arginase deficiency. This child has significant neurologic
sequelae that might have been ameliorated with a more prompt diagnosis and treatment.
However, it is uncertain if early diagnosis and institution of therapy would have prevented his
liver disease. Arginase deficiency should be considered in older children and adults with lower
limb spasticity, especially when accompanied by ataxia, seizures, mental retardation or liver
abnormalities.
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