Distinguishing CLN2 (Batten Disease): Navigating the differential diagnosis and referral pathways

‍This webinar addresses why NCL type 2 (CLN2/Batten) disease is so often missed in its earliest stages, even though the median diagnostic delay from first symptom to confirmed diagnosis is about 22 months.  Pasquale Striano and  Dr Marina Trivisano explain that early presentations, language delay, a first seizure, clumsiness, or behavioral change, look like common pediatric problems when considered in isolation, and that clinicians tend to anchor on the first plausible diagnosis (developmental delay, autism, epilepsy) rather than revisiting it as new findings emerge.

The core message is that CLN2 is recognized longitudinally: what matters is not a single symptom but the trajectory of change over time, and clinicians should actively distinguish delay (slower than expected but ongoing progress), plateau (progress stops), and regression (skills are lost), since regression is never part of uncomplicated developmental delay and should always trigger reassessment.

The talk sets out a practical diagnostic framework: when two or more red flags overlap, particularly language delay, a sense of regression, and one or more seizures, disease-specific testing is justified without waiting for the full textbook phenotype, since the therapeutic window is defined by how much neurological function remains rather than by age alone.

It covers the case for parallel rather than sequential testing (enzyme activity assay alongside gene panel or exome/genome sequencing, ensuring the TPP1 gene is included), the importance of clear ownership of the diagnostic next step to avoid diffusion of responsibility between pediatricians, neurologists, and metabolic teams, and key neurophysiological and imaging biomarkers, including the low-frequency photoparoxysmal response on EEG (present in most patients when specifically tested for) and posterior white matter abnormalities and cerebellar atrophy on brain MRI. The session closes with three illustrative patient cases showing different diagnostic routes to confirmed CLN2, and a live Q&A on the most common causes of delayed diagnosis in clinical practice.

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References: (1) Fietz M et al. Mol Genet Metab 2016;119:160–7 (expert recommendations) (2) Williams RE et al. Pediatr Neurol 2017;69:102–12 (3) Mole SE et al. Orphanet J Rare Dis 2021;16:185

This webinar is intended for healthcare professionals only.
This is a promotional webinar sponsored and funded by BioMarin. BioMarin medicines will be discussed.

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