The neuronal ceroid lipofuscinoses (NCL, Batten disease) are a group of 13 inherited lysosomal storage disorders characterised by neurodegeneration, seizures, visual failure and a progressive decline in cognitive and motor abilities. They can present at any age though most often they begin in childhood.
The introduction of enzyme replacement therapy (ERT) for the treatment of NCL type 2 disease (CLN2) has produced dramatic improvements in disease management. Assessment of therapeutic effect for ERT are limited to clinical observational measures, namely the CLN2 Clinical Rating Scale, a subjective measure of motor and language performance. To address this, we examined lymphocytes in blood buffy coats by electron microscopy, to identify the specific abnormal storage product present in NCL 2. We observed a dramatic reduction of affected cells over the course of treatment and propose that this reliable and minimally invasive test may form part of a panel of biomarker to examine these complex disorders.