The National Niemann-Pick C1 disease database: report of clinical features and health problems.

Niemann-Pick type C1 (NPC1) disease is an autosomal recessive disorder characterized clinically by neonatal jaundice, hepatosplenomegaly, vertical gaze palsy, ataxia, dystonia, and progressive neurodegeneration. The present study provides basic clinical and health information from the National Niemann-Pick C1 disease database that was obtained using a clinical questionnaire of 83 questions mailed to families affected by NPC1 disease living in the United States. The study was conducted over a 1-year period, during which time parents/caregivers and physicians completed the clinical questionnaire. Sixty-four percent (87/136) of the questionnaires were returned, with 53% and 47% representing male and female NPC1 patients, respectively. The average age of diagnosis for NPC1 disease was 10.4 years, with one-half of patients being diagnosed before the age of 6.9 years. The average age of death for NPC1 disease was 16.2 years, with one-half of patients dying before the age of 12.5 years. A common clinical symptom reported at birth was neonatal jaundice (52%), followed by enlargement of the spleen (36%) and liver (31%); ascites (19%) and neonatal hypotonia (6%) were much less frequent. With respect to developmental difficulties, the most common findings included clumsiness (87%), learning difficulties (87%), ataxia (83%), dysphagia (80%), and vertical gaze palsy (81%). Together, these findings confirm and extend previous reports investigating the clinical features associated with NPC1 disease.