Occurrence of and mortality from childhood neuronal ceroid lipofuscinoses in norway.

The aim of this study was to estimate the prevalence of, incidence of, and survival from childhood neuronal lipofuscinoses in Norway. All children with neuronal ceroid lipofuscinoses living in Norway are referred to the Tambartun National Resource Centre for the Visually Impaired. We based the data collection on the medical records at Tambartun. We identified 70 children with neuronal ceroid lipofuscinoses who were born in Norway from 1957 to 1998. Seven had a diagnosis of late infantile neuronal ceroid lipofuscinoses, and 63 had the juvenile form of neuronal ceroid lipofuscinoses. In 2005, the prevalence of childhood neuronal ceroid lipofuscinoses was 8.3 per million inhabitants in Norway, and all children were diagnosed with the juvenile form. The average annual incidence rate of childhood neuronal ceroid lipofuscinoses was 1.8 per 100,000 live births using the years from 1957 to 1978 and 3.9 using the years from 1978 to 1999. The trend in incidence increased at an annual rate of about 3.3% per year (P = .001), averaged over this period. Restricted to the most recent period (1967-1998), the trend was much weaker (1.4% increase per year; P = .3), and confidence intervals included the possibility of no trend. The median age at death of children diagnosed with late infantile neuronal ceroid lipofuscinoses was 12 years (95% confidence interval 9-14) and 26 years (95% confidence interval 25-30) for children diagnosed with the juvenile form. The results did not support the hypothesis that children with neuronal ceroid lipofuscinoses born in 1975 or later lived longer than those born from 1957 to 1975 (relative risk 1.0, 95% confidence interval 0.36-2.8). Mortality was similar for both genders (hazard ratio 0.97, 95% confidence interval 0.4-2.2).