Sepiapterin reductase deficiency in a 2-year-old girl with incomplete response to treatment during short-term follow-up.
J Inherit Metab Dis
; 32 Suppl 1: S5-10, 2009 Dec.
Article
in En
| MEDLINE
| ID: mdl-19130291
ABSTRACT
Sepiapterin reductase (SR) catalyses the last step in the tetrahydrobiopterin biosynthesis pathway; it converts 6-pyruvoyl-tetrahydropterin (6-PTP) to BH(4) in an NADPH-dependent reaction. SR deficiency is a very rare autosomal recessive disorder with normal phenylalanine (Phe) concentration in blood and diagnostic abnormalities are detected in CSF. We present a 16-month-old girl with SR deficiency. From the newborn period she presented with an adaptation regulatory disorder. At the age of 3 months, abnormal eye movements with dystonic signs and at 4.5 months psychomotor retardation were noticed. Since that time axial hypotonia with limb spasticity (or rather delayed reflex development), gastro-oesophageal reflux and fatigue at the end of the day has been observed. Brain MRI was normal; EEG was without epileptiform discharges. Analysis of biogenic amine metabolites in CSF at the age of 16 months showed very low HVA and 5-HIAA concentrations. Analysis of CSF pterins revealed strongly elevated dihydrobiopterin (BH(2)), slightly elevated neopterin and elevated sepiapterin levels. Plasma and CSF amino acids concentrations were normal. A phenylalanine loading test showed increased Phe after 1 h, 2 h and 4 h and very high Phe/Tyr ratios. SR deficiency was confirmed in fibroblasts and a novel homozygous g.1330C>G (p.N127K) SPR mutation was identified. On L-dopa and then additionally 5-hydroxytryptophan, the girl showed slow but remarkable progress in motor and intellectual ability. Now, at the age of 3 years, she is able to sit; expressive speech is delayed (to 1 1/2 years), passive speech is well developed. Her visual-motor skills, eye-hand coordination and social development correspond to the age of 2 1/2 years.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Psychomotor Disorders
/
Alcohol Oxidoreductases
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Dystonia
/
Metabolism, Inborn Errors
Type of study:
Observational_studies
/
Prognostic_studies
Limits:
Child, preschool
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Female
/
Humans
Language:
En
Journal:
J Inherit Metab Dis
Year:
2009
Document type:
Article
Affiliation country:
Poland