Abstracts

Rationale:
Potocki-Lupski Syndrome (PTLS) is a genetic disorder caused by duplication in 17p11.2. The various recognized symptoms include developmental delays including language and cognitive impairment, hypotonia, oropharyngeal dysphagia, failure to thrive during infancy and features of autism spectrum disorder. While abnormal EEGs are seen in PTLS, this diagnosis lacks an association with epilepsy. Our intent is to describe a patient with PTLS, epilepsy, and electrical status epilepticus in sleep (ESES) and to broaden the clinical spectrum of PTLS.
Method:
Literature review in conjunction with chart review.
Results:
A 21-month-old female born at 37 weeks gestational age referred for evaluation of developmental delays and staring spells. The patient did not sit unassisted until 9 months and was not walking until 19 months. The staring spells began in infancy lasting up to 30 seconds. During these, she was unresponsive to touch or sound. Brain MRI was normal, but EEG showed bilateral centrotemporal spikes. She was started on oxcarbazepine given concerns for an epileptic etiology. Shortly thereafter, the patient developed her first generalized tonic-clonic seizure with prolonged duration of over 20 minutes. Genetic testing (Invitae epilepsy panel) uncovered variants of unknown significance in KCNH2 gene and QARS gene, and CGH showed an area of homozygosity at 13q21.1, and a duplication at 17p11.2, consistent with PTLS. Further seizure activity led to additional anticonvulsants clobazam, zonisamide and levetiracetam being tried over a period of 10 months. Clobazam and levetiracetam were not tolerated due to increasing episodes and behavioral concerns. Patient showed declines in ambulation having frequent falls, along with decreasing use of verbal communication, and frequent breakthrough seizures lasting between 1 and 10 minutes. At 32 months of age, 24-hour continuous video EEG showed sleep potentiated independent multifocal epileptiform discharges more prominent on the left side, with spike-wave index of 30-40% during wakefulness and 70-90% during sleep, which was consistent with ESES.
Conclusion:
PTLS is a genetic condition which affects multiple organ systems and is associated with developmental delays. EEG abnormalities have been reported including diffuse background slowing focal and generalized epileptiform discharges. While non-epileptic behavioral spells and abnormal movements are common in patients with developmental delays, neither clinical nor electrographic seizures have been previously reported in PTLS patients. This case expands the recognized phenotypic presentation of PTLS. Epilepsy, subclinical seizures and ESES should be considered in patients with known or suspected PTLS, particularly in the setting of developmental regression.
Funding:
:No funding received