J Genet Med.
2009 Dec;6(2):170-174.
A Case of Dihydropteridine Reductase Deficiency
- Affiliations
-
- 1Department of Pediatrics, College of Medicine, Soonchunhyang University, Korea.ldh@hosp.sch.ac.kr
- 2Department of Laboratory Medicine & Genetics, Soonchunhyang University Bucheon Hospital and Soonchunhyang University College of Medicine, Korea.
- 3Department of Laboratory Medicine & Genetics, Samsung Medical Center, ungkyunkwan University School of Medicine, Korea.
Abstract
- Tetrahydrobiopterin (BH4) deficiency is caused by mutations in genes encoding enzymes involved in the synthesis and regeneration of BH4. The condition is usually accompanied by hyperphenylalaninemia (HPA) and deficiency of neurotransmitter precursors L-dopa and 5-hydroxytryptophan. BH4 deficiency is much rarer than classical phenylketonuria. Dihydropteridine reductase (DHPR) deficiency, an autosomal recessive genetic disorder, is a cause of malignant hyperphenylalaninemia due to BH4 deficiency. When left untreated, DHPR deficiency leads to neurologic deterioration at the age of 4 or 5 months, including psychomotor retardation, tonicity disorders, drowsiness, irritability, abnormal movements, hyperthermia, hypersalivation, and difficulty swallowing. Treatment of DHPR deficiency should be initiated as early as possible with BH4 supplementation and replacement of the neurotransmitter precursors L-dopa and 5-hydroxytryptophan. We report the first case of DHPR deficiency in Korea, a child diagnosed at 9 years of age by genetic testing.