Peripheral nervous system in gyrate atrophy of the choroid and retina with hyperornithinemia.
OBJECTIVE
To evaluate peripheral nervous system involvement in gyrate atrophy of the choroid and retina with hyperornithinemia (GA).


BACKGROUND
GA is an inborn error of amino acid metabolism caused by mutations in the enzyme ornithine aminotransferase. Patients with GA have hyperornithinemia, progressive centripetal loss of vision, minor CNS abnormalities, and type II muscle fiber atrophy with accumulation of tubular aggregates. The authors previously showed that muscle and brain creatine stores are depleted in the patients with GA.


METHODS
The authors searched evidence of peripheral nervous involvement in 40 patients with GA (mean age 31.6 +/- 16.3 years; range 5 to 74 years) by using neurography, quantitative sensory threshold testing, and evoked potential testing.


RESULTS
Neurography revealed abnormalities in 21 (53%) of the patients. The abnormalities associated with the severity of the ophthalmologic changes and the age of the patients. With quantitative sensory threshold testing, abnormal large-fiber function was found in seven (18%) and abnormal small-fiber function was found in four (10%) patients. Somatosensory evoked potential and brainstem auditory evoked potential responses were abolished in five patients.


CONCLUSIONS
These findings of peripheral nervous system involvement in GA suggest that GA is a systemic disease affecting not only CNS but also the peripheral nervous system.
Peltola
K E
KE
Department of Pediatrics, Turku University Central Hospital, Turku, Finland. katja.peltola@utu.fi
Jääskeläinen
S
S
Heinonen
O J
OJ
Falck
B
B
Näntö-Salonen
K
K
Heinänen
K
K
Simell
O
O
D000293:Adolescent; D000328:Adult; D000368:Aged; D015862:Choroid Diseases / Q000097:blood / Q000235:genetics / Q000503:physiopathology*; D004576:Electromyography; D016057:Evoked Potentials, Auditory, Brain Stem; D005073:Evoked Potentials, Somatosensory; D005260:Female; D018703:Founder Effect; D015799:Gyrate Atrophy / Q000097:blood / Q000235:genetics / Q000503:physiopathology*; D006720:Homozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009952:Ornithine / Q000097:blood*; D017933:Peripheral Nervous System / Q000503:physiopathology*; D012164:Retinal Diseases / Q000097:blood / Q000235:genetics / Q000503:physiopathology*; D012684:Sensory Thresholds
D009952:Ornithine