Recenzija, Prikaz slučaja

https://doi.org/10.11613/BM.2018.030801

Metabolic follow-up of a Croatian patient with gyrate atrophy and a new mutation in the OAT gene: a case report

Marija Zekušić ; Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
Ana Škaričić ; Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
Ksenija Fumić ; Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
Dunja Rogić ; Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
Tamara Žigman ; Department of Pediatrics, University Hospital Center Zagreb, Zagreb, Croatia
Danijela Petković Ramadža ; Department of Pediatrics, University Hospital Center Zagreb, Zagreb, Croatia; School of Medicine, University of Zagreb, Zagreb, Croatia
Nenad Vukojević ; Department of Ophthalmology, University Hospital Center Zagreb, Zagreb, Croatia
Véronique Rüfenacht ; Division of Metabolism, University Children’s Hospital, Zürich, Switzerland
Valentina Uroić ; Department of Nutrition and Dietetics, University Hospital Center Zagreb, Zagreb, Croatia
Ivo Barić ; Department of Pediatrics, University Hospital Center Zagreb, Zagreb, Croatia; School of Medicine, University of Zagreb, Zagreb, Croatia

Sažetak

Gyrate atrophy (GA) of the choroid and retina is a rare autosomal recessive disorder that occurs due to deficiency of the mitochondrial enzyme ornithine
aminotransferase (OAT). Hyperornithinemia causes degeneration of the retina with symptoms like myopia, reduced night vision and progressive
vision loss. Our patient is a 10-year-old girl with impaired vision and strabismus. As part of the metabolic work-up, plasma amino acid analysis
revealed significantly increased concentration of ornithine (1039 μmol/L; reference interval 20 - 155 μmol/L). Molecular genetic analysis revealed
homozygous mutation in exon 7 of the OAT gene that has not been reported previously (c.868_870delCTT p.(Leu290del)). This in frame deletion
was predicted to be deleterious by in silico software analysis. Our patient was treated with pyridoxine (vitamin B6 in a dose of 2 x 100 mg/day),
low-protein diet (0.6 g/kg/day) and L-lysine supplementation which resulted in a significant reduction in plasma ornithine concentrations to 53%
of the initial concentration and the ophthalmologic findings showed significant improvement. We conclude that low protein diet and lysine supplementation
can lead to long-term reduction in plasma ornithine concentrations and, if started at an early age, notably slow the progression of retinal
function loss in patients with GA. The effect of therapy can be reliably monitored by periodical measurement of plasma ornithine concentration. To
our knowledge, this is the first report of OAT deficiency in Croatia.

Ključne riječi

ornithinemia; amino acids; tandem mass spectrometry

Hrčak ID:

206788

URI

https://hrcak.srce.hr/206788

Datum izdavanja:

15.10.2018.

Posjeta: 1.797 *