Effects of miglustat therapy on neurological disorder and survival in early-infantile Niemann-Pick disease type C: a national French retrospective study.

BACKGROUND: Niemann-Pick disease type C (NP-C) is a rare neurovisceral lysosomal lipid storage disease characterized by progressive neurodegeneration and premature death. While miglustat can stabilize neurological manifestations in later onset forms of NP-C, its efficacy in the early-infantile neurological form has not been demonstrated. In this observational retrospective study, we compared long-term neurodevelopmental outcome and survival between an untreated and a treated group of early infantile NP-C patients. METHODS: Data available on all NP-C patients with early infantile neurological onset diagnosed in France between 1990 and 2013 were compiled. Patients with incomplete data or who had died from a systemic perinatal, rapidly fatal form were excluded. RESULTS: Ten patients were included in the treated group (year of birth: 2006-2012), and 16 patients in the untreated group [born 1987-2005 (n = 15), 2012 (n = 1)]. The median age at neurological onset was 9 months (5-18) in the treated group, and 12 months (3-18) in the untreated group (p = 0.22). Miglustat therapy was started at a median age of 24.5 months (9-29) and median duration was 30 months (11-56). Gastrointestinal adverse events were reported in 7/10 patients on miglustat. All patients developed loss of psychomotor acquisitions or additional neurological symptoms despite miglustat therapy. The ages of developmental milestones and neurological involvement did not significantly differ between the two groups. Four patients in the untreated group were lost to follow up. The 22 remaining patients had died by the end of the study and no patient survived beyond the age of 7.4 years. The median survival age was 4.42 years in the untreated group and 5.56 years in the treated group; the Kaplan-Meier survival curves were not significantly different (log-rank test: p = 0.11). CONCLUSIONS: Miglustat allowed no significant long-term neurodevelopmental improvement nor significant increase of survival in patients with early infantile NP-C.

UQCRC2-related mitochondrial complex III deficiency, about 7 patients.

Isolated complex III defect is a relatively rare cause of mitochondrial disorder. New genes involved were identified in the last two decades, with only a few cases described for each deficiency. UQCRC2, which encodes ubiquinol-cytochrome c reductase core protein 2, is one of the eleven structural subunits of complex III. We report seven French patients with UQCRC2 deficiency to complete the phenotype reported so far. We highlight the similarities with neoglucogenesis defect during decompensations - hypoglycaemias, liver failure and lactic acidosis - and point out the rapid improvement with glucose fluid infusion, which is a remarkable feature for a mitochondrial disorder. Finally, we discuss the relevance of coenzyme Q10 supplementation in this defect.

Miglustat therapy in the French cohort of paediatric patients with Niemann-Pick disease type C.

BACKGROUND: Niemann-Pick disease type C (NP-C) is a rare neurovisceral lysosomal lipid storage disease characterized by progressive neurological deterioration. Published data on the use of miglustat in paediatric patients in clinical practice settings are limited. We report findings from a prospective open-label study in the French paediatric NP-C cohort. METHODS: Data on all paediatric NP-C patients treated with miglustat in France between October 2006 and December 2010 were compiled. All patients had a confirmed diagnosis of NP-C, and received miglustat therapy according to manufacturer's recommendations. Pre-treatment and follow-up assessments were conducted according to a standardized protocol. RESULTS: Twenty children were enrolled; 19 had NPC1 gene mutations and 1 had NPC2 gene mutations. The median age at diagnosis was 1.5 years, and the median age at miglustat initiation was 6.0 years. Eight NPC1 patients had the early-infantile, eight had the late-infantile, and three had the juvenile-onset forms of NP-C. A history of hepatosplenomegaly and/or other cholestatic symptoms was recorded in all 8 early-infantile onset patients, 3/8 late-infantile patients, and 1/3 juvenile onset patients. Brain imaging indicated white matter abnormalities in most patients. The median (range) duration of miglustat therapy was 1.3 (0.6-2.3) years in early-infantile, 1.0 (0.8-5.0) year in late-infantile, and 1.0 (0.6-2.5) year in juvenile onset patients. NP-C disability scale scores indicated either stabilization or improvement of neurological manifestations in 1/8, 6/8, and 1/3 NPC1 patients in these subgroups, respectively. There were no correlations between brain imaging findings and disease course. Mild-to-moderate gastrointestinal disturbances were frequent during the first 3 months of miglustat therapy, but were easily managed with dietary modifications and/or anti-propulsive medication. CONCLUSIONS: Miglustat can improve or stabilize neurological manifestations in paediatric patients with the late-infantile and juvenile-onset forms of NP-C. Among early-infantile onset patients, a shorter delay between neurological disease onset and miglustat initiation was associated with an initial better therapeutic outcome in one patient, but miglustat did not seem to modify overall disease course in this subgroup. More experience is required with long-term miglustat therapy in early-infantile onset patients treated from the very beginning of neurological manifestations.