Lysinuric protein intolerance (Hyperammonemia disorder). Dibasicaminoaciduria II.
Incidence
Autosomal recesive. It is a familial disorder of dibasic aminoacid transport.
Clinical Characteristics
Patients are symptom-free while are breast-fed. Then, when protein intake increase= refusal to feed, FTT, coma upon ingesting high protein diets. While fasting= nl ammonia but very high postprandially. Late hepatoesplenomegaly, sparse hair, osteoporosis, Mild MR, Insterstitial lung disease, may be fatal. Massive dibasic aminoaciduria (mainly lysine, but also arginina & ornithine). Generalized increase of aminoacids in blood, but low dibasic AA.
Precipitants
Protein ingestion. In 2 patients with Lysinuric Protein Intolerance, Michael Geraghty have seen peak ammonium values between 1-2 hours post protein load.
Provocation Tests
no
Diagnostic Procedures
Aminoacids in urine