Use of miglustat in a child with late-infantile-onset Niemann-Pick disease type C and frequent seizures: a case report.

INTRODUCTION: Niemann-Pick disease type C is a rare genetic lysosomal storage disease associated with impaired intracellular lipid trafficking and a range of progressive neurological manifestations. The influence of seizure activity on disease course and response to miglustat therapy is not currently clear. CASE PRESENTATION: Niemann-Pick disease type C homozygous for NPC1 mutation p.S940L [c. 2819 C>T] was diagnosed in a four-and-a-half-year-old Norwegian Caucasian girl. The patient, who died at eight years and seven months of age, had a history of prolonged neonatal jaundice and subsequently displayed progressive neurological manifestations that started with delayed speech, ataxia, and gelastic cataplexy. A regimen of 100mg of miglustat three times a day was initiated when she was four years and 11 months old. She showed decreased neurological deterioration during about three and a half years of treatment. However, she displayed periods of distinct worsening that coincided with frequent epileptic seizures. Anti-epileptic therapy reduced seizure frequency and severity and allowed re-stabilization of her neurological function. Prior to her death, which was possibly due to acute cardiac arrest, seizure activity was well controlled. CONCLUSIONS: Miglustat delayed the expected deterioration of neurological function in this patient with p.S940L-homozygous late-infantile-onset Niemann-Pick disease type C and provided important quality-of-life benefits. This case demonstrates the importance of effective seizure control therapy in achieving and maintaining neurological stabilization in Niemann-Pick disease type C.

Leukoencephalopathy with accumulated succinate is indicative of SDHAF1 related complex II deficiency.

BACKGROUND: Deficiency of complex II (succinate dehydrogenase, SDH) represents a rare cause of mitochondrial disease and is associated with a wide range of clinical symptoms. Recently, mutations of SDHAF1, the gene encoding for the SDH assembly factor 1, were reported in SDH-defective infantile leukoencephalopathy. Our goal was to identify SDHAF1 mutations in further patients and to delineate the clinical phenotype. METHODS: In a retrospective data collection study we identified nine children with biochemically proven complex II deficiency among our cohorts of patients with mitochondrial disorders. The cohort comprised five patients from three families affected by SDH-defective infantile leukoencephalopathy with accumulation of succinate in disordered cerebral white matter, as detected by in vivo proton MR spectroscopy. One of these patients had neuropathological features of Leigh syndrome. Four further unrelated patients of the cohort showed diverse clinical phenotypes without leukoencephalopathy. SDHAF1 was sequenced in all nine patients. RESULTS: Homozygous mutations of SDHAF1 were detected in all five patients affected by leukoencephalopathy with accumulated succinate, but not in any of the four patients with other, diverse clinical phenotypes. Two sisters had a mutation reported previously, in three patients two novel mutations were found. CONCLUSION: Leukoencephalopathy with accumulated succinate is a key symptom of defective complex II assembly due to SDHAF1 mutations.