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Updated: Jul 13, 2026
Antibody Profiling by Luciferase Immunoprecipitation Systems (LIPS)
Published on: October 7, 2009
First reported case of lysinuric protein intolerance (LPI) in Lithuania, confirmed biochemically and by DNA analysis
Loreta Cimbalistiene1, Willy Lehnert, Kirsi Huoponen
1Department of Human and Medical Genetics, Vilnius University, Vilnius, Santariskiu 2, Lithuania. loreta.cimbalistiene@santa.vu.lt
Insights
This case study highlights a rare genetic disorder, lysinuric protein intolerance (LPI), diagnosed after a 17-year delay. Early diagnosis is crucial for managing LPI and preventing severe health complications.
Area of Science:
- Medical Genetics
- Biochemistry
- Pediatrics
Background:
- Lysinuric protein intolerance (LPI) is a rare autosomal recessive metabolic disorder.
- It is characterized by defects in the cationic amino acid transporter, leading to impaired amino acid transport.
Observation:
- An 18-year-old Lithuanian female presented with hepatosplenomegaly, lactase deficiency, congenital cataract, and osteoporosis.
- Symptoms included drowsiness after high-protein meals, delayed diagnosis for 17 years, and various aminoacidurias (citrullinuria, lysinuria, etc.).
Findings:
- Laboratory results revealed mild hyperammonaemia and elevated plasma amino acids (citrulline, alanine, glycine, etc.).
- Molecular genetic testing identified a mutation in the SLC7A7 gene, confirming the diagnosis of LPI.
Implications:
- This case underscores the diagnostic challenges and prolonged delays in identifying LPI.
- Highlights the importance of considering LPI in patients with unexplained hyperammonaemia and aminoaciduria.
- Emphasizes the need for early genetic testing and timely therapeutic intervention for LPI patients.
Abstract:
We report on an 18-year-old Lithuanian girl with hepatosplenomegaly noticed at birth, which progressed thereafter. The patient had to wait about 17 years for an accurate diagnosis and appropriate therapy. Lactase deficiency, congenital cataract of the right eye, and osteoporosis were observed. Episodes of drowsiness were caused by intake of high-protein food. Laboratory findings included slight hyperammonaemia, high plasma Citr, Ala, Gly, Glu, Ser levels, as well as citrullinuria, lysinuria, glutaminuria, alaninuria, argininuria, prolinuria, hydroxyprolinuria, ornithinuria, and orotic aciduria. Aversion to high-protein diet strongly suggested a disorder resulting in hyperammonaemia. Citrullinaemia was suspected. Subsequently the diagnosis of LPI was made on the basis of biochemical and clinical features. Molecular genetic testing revealed a mutation in the SLC7A7 gene, confirming the diagnosis.
