Welcome to Cross-Canada Paediatric - Respiratory Residency Rounds


Mustafa Osman,
Clinical Fellow, Pediatric Respiratory Medicine
University of Toronto


A 2 and 1/2 year old boy with lysinuric protein intolerance presented with recurrent respiratory distress. He was born at term with no perinatal issues but did start to fail to thrive soon after weaning.


In June 2006, at the age of 1, he presented acutely unwell with hepato-splenomegaly. A metabolic investigation showed massive amounts of lysine, arginine and ornithine in the urine and he was diagnosed with Lysinuric Protein Intolerance(LPI). Genetic testing subsequently confirmed the LPI. Two other siblings were healthy and his mother and father were carriers. He was managed successfully with dietary restriction and citrulline apart from a brief spell of hyperammonemia in November 2006. Around the same time he was admitted with para-influenza. He had further "chest infections" and had immune studies done which were normal. His presumed respiratory infections occurred every 2 months and would typically require hospitalisation and antibiotics. In March 2006 he presented with fever and tachypnea which were initially nocturnal, but became diurnal. Bronchoscopy showed diffuse chronic bronchitis prevalent in right and left lower lobes. Esophagoscopy and biopsy were non-contributory though he was treated with anti-reflux treatment with reported improvement.

Images from high resolution CT scan

Figure 1a

Figure 1b

Figure 1c

Figure 1d

What does the CT scan show?

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