title: Sulfite oxidase deficiency--an unusual late and mild presentation.
abstract: BACKGROUND
  Sulfite oxidase deficiency (SOD) is an autosomal recessive inherited disease usually presenting in the neonatal period with severe neurological symptoms including seizures, often refractory to anticonvulsant therapy, and a rapidly progressive encephalopathy resembling neonatal hypoxic ischemia, with premature death. Most patients develop dislocated ocular lenses. Later or milder presentations of SOD are being reported with increasing frequency. These presentations include neurological regression with loss of previously acquired milestones or movement disorders.
  
  
  METHODS
  We report a four years old girl presenting with intermittent ataxia and uncoordinated limb movements. A similar episode of ataxia had occurred previously, one year before, with complete neurologic recovery and normal developmental milestones. Bilateral lens dislocation had been recently diagnosed. Cranial MRI demonstrated bilateral globus pallidus enhancement. Low homocysteine was found in plasma and Sulfitest(R) was positive. Further investigations led to confirmation of isolated sulfite oxidase deficiency with no enzyme activity detected on skin fibroblasts culture.
  
  
  CONCLUSIONS
  This case illustrates the clinical variability of SOD and it is not only atypical but also seems to be the mildest form described so far. The association of ectopia lentis with a movement disorder, even without psychomotor regression, should prompt us to look for this diagnosis.
authors: Paediatric Neurology Department, Hospital de Dona Estefânia, Centro Hospitalar Lisboa Central EPE, Lisbon, Portugal.
authors: Susana
authors: S
authors: Rocha
authors: Metabolic Diseases Unit, Hospital de Dona Estefânia, Centro Hospitalar Lisboa Central EPE, Lisbon, Portugal.
authors: Ana Cristina
authors: AC
authors: Ferreira
authors: Paediatric Neurology Department, Hospital de Dona Estefânia, Centro Hospitalar Lisboa Central EPE, Lisbon, Portugal.
authors: Ana Isabel
authors: AI
authors: Dias
authors: Paediatric Neurology Department, Hospital de Dona Estefânia, Centro Hospitalar Lisboa Central EPE, Lisbon, Portugal.
authors: José Pedro
authors: JP
authors: Vieira
authors: Metabolic Diseases Unit, Hospital de Dona Estefânia, Centro Hospitalar Lisboa Central EPE, Lisbon, Portugal. Electronic address: metabolicas@chlc.min-saude.pt.
authors: Sílvia
authors: S
authors: Sequeira
mesh_terms: D017668:Age of Onset; D000592:Amino Acid Metabolism, Inborn Errors / Q000150:complications / Q000235:genetics*; D002675:Child, Preschool; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008279:Magnetic Resonance Imaging; D009154:Mutation / Q000235:genetics*; D012640:Seizures / Q000175:diagnosis / Q000209:etiology / Q000235:genetics*; D050876:Sulfite Oxidase / Q000172:deficiency* / Q000235:genetics
chemical_list: D050876:Sulfite Oxidase
keywords: Ataxia; Ectopia lentis; Globus pallidus; Homocysteine; Sulfite oxidase