Koolen‐de Vries syndrome associated with continuous spike‐wave in sleep

Abstract

Koolen-de Vries syndrome (KdVS) is a genetic condition caused by 17q21.31 microdeletions or pathogenic variants in KANSL1. Affected patients most commonly exhibit some or all of the following: neonatal hypotonia, developmental impairment, facial dysmorphic features, and congenital malformations. Epilepsy occurs in approximately half, often with phenotypes on the epilepsyaphasia spectrum. We describe six children with KdVS found to have continuous spike-wave in sleep (CSWS) on EEG, four of whom were diagnosed with epileptic encephalopathy with CSWS and two with Landau-Kleffner syndrome. When compared with other children with CSWS on EEG, patients with KdVS may present at slightly later ages and with a longer interval between seizure diagnosis and identification of CSWS. There is no clear best treatment for children with CSWS, but two patients in our cohort were trialed on a variation of the ketogenic diet, and both reported clinical improvement. In one of the patients, the response was dramatic, and CSWS recurred when weaning of the ketogenic diet was attempted. Based on our findings, an EEG capturing a prolonged period of sleep should be arranged in any child with KdVS presenting with developmental regression or plateau, particularly if they have a preceding history of seizures.

Continuous Spike–Waves during Slow Sleep Today: An Update

“…Two cases underwent a KD variation, and for both, a clinical improvement was reported. The authors concluded that a prolonged EEG during sleep should be performed in all KdVS children showing a regression or plateau of development, especially when there is a previous history of seizures [263]. Mowat-Wilson syndrome is a rare genetic disease due to a heterozygous deletion or function loss of the ZEB2 gene located on chromosome 2.…”

Koolen-de Vries Syndrome: a journey from diagnosis to treatments

“…Koolen-de Vries Syndrome (KdVS) is a multi-system disorder due to a de novo, heterozygous 17q21.31 deletion or pathogenic variant in the KANSL1 gene. 1 KdVS is characterized by neonatal hypotonia, developmental delay, intellectual disability, speech difficulties, 2 epilepsy, 3 , 4 congenital abnormalities of the heart and/or urogenital system, respiratory problems, ophthalmic issues, facial dysmorphism and musculoskeletal problems. 5 , 6 Some children with KdVS are born with one or more congenital abnormalities, 5 and a large portion present with neonatal hypotonia and feeding problems.…”