Epilepsy as a Novel Phenotype of BPTF-Related Disorders.

BACKGROUND: Neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL) is associated to BPTF gene haploinsufficiency. Epilepsy was not included in the initial descriptions of NEDDFL, but emerging evidence indicates that epileptic seizures occur in some affected individuals. This study aims to investigate the electroclinical epilepsy features in individuals with NEDDFL. METHODS: We enrolled individuals with BPTF-related seizures or interictal epileptiform discharges (IEDs) on electroencephalography (EEG). Demographic, clinical, genetic, raw EEG, and neuroimaging data as well as response to antiseizure medication were assessed. RESULTS: We studied 11 individuals with a null variant in BPTF, including five previously unpublished ones. Median age at last observation was 9 years (range: 4 to 43 years). Eight individuals had epilepsy, one had a single unprovoked seizure, and two showed IEDs only. Key features included (1) early childhood epilepsy onset (median 4 years, range: 10 months to 7 years), (2) well-organized EEG background (all cases) and brief bursts of spikes and slow waves (50% of individuals), and (3) developmental delay preceding seizure onset. Spectrum of epilepsy severity varied from drug-resistant epilepsy (27%) to isolated IEDs without seizures (18%). Levetiracetam was widely used and reduced seizure frequency in 67% of the cases. CONCLUSIONS: Our study provides the first characterization of BPTF-related epilepsy. Early-childhood-onset epilepsy occurs in 19% of subjects, all presenting with a well-organized EEG background associated with generalized interictal epileptiform abnormalities in half of these cases. Drug resistance is rare.

The effect of growth hormone treatment in children with novel BPTF gene variants: A report of two cases and literature review.

BACKGROUND: Neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL) is a rare neurodevelopmental disease caused by BPTF gene variants. To date, there are only 36 cases reported in the literature, and patients mainly presented with a developmental delay, language delay, and microcephaly. About 35% of the patients had short stature, but there had no reports published on the treatment. METHODS: The exome sequencing was performed in two probands. Sanger sequencing was used to confirm the identified variants both in probands and their parents. RESULTS: As for the Chinese population, we report two novel variants in BPTF gene (NM_004459.6: c.1133G>A, c.5941delC) causing NEDDFL from two unrelated families. Both children had short stature and responded to recombinant human growth hormone (rhGH) treatment - the first report of this therapy in NEDDFL patients. CONCLUSION: Our findings broaden the genotypic spectrum of BPTF variants. The salutary effect of rhGH in the NEDDFL is documented.