International consensus on clinical severity scale use in evaluating Niemann-Pick disease Type C in paediatric and adult patients: results from a Delphi Study.

In achieving a consensus on the use of the 17-domain NPCCSS scale as the first choice for assessing clinical severity of NPC in clinical trial settings but prioritising the domains in the 5-domain NPCCSS scale for routine clinical practice, this study can help to inform future discussion around the use of the existing NPC clinical severity scales. For routine clinical practice, the study helps provide clarity on which scale is favoured by a significant proportion of a representative body of experts, in this case, the 5-domain NPCCSS scale.