Objective: To determine the prevalence of and identify factors associated with gastrointestinal (GI) symptoms among patients with channelopathy-associated developmental and epileptic encephalopathy (DEE).

Study design: Parents of 168 patients with DEEs linked to SCN1A (N=59), KCNB1 (N=31), or KCNQ2 (N=78) completed online CLIRINX surveys about their children's GI symptoms. Analysis examined prevalence, frequency, and severity of GI symptoms, as well as DEE type, functional mobility, feeding difficulties, ketogenic diet, anti-seizure medication, autism spectrum disorder (ASD), and seizures. Statistical analyses included chi-square tests, Wilcoxon rank-sum analyses, and multiple logistic regression.

Results: Patients (median age of 6.3 years; 92 [55%] females) included 59 (44%) with SCN1A-DEE, 31 (35%) with KCNB1-DEE, and 78 (71%) with KCNQ2-DEE. GI symptoms were reported in 92/168 (55%) patients among whom 63/86 (73%) reported daily or weekly symptoms, 29/92 (32%) had frequent or serious discomfort, and 13/91 (14%) had appetite disturbances as a result. After adjustment for DEE type, current use of ketogenic diet (6% reported), and gastrostomy tube (13% reported) were both associated with GI symptoms in a statistically, but not clinically significant manner (P < .05). Patient age, functional mobility, feeding difficulties, ASD, and seizures were not clearly associated with GI symptoms. Overall, no individual anti-seizure medication was significantly associated with GI symptoms.

Conclusions: GI symptoms are common and frequently severe in DEE patients.

Keywords: Constipation; gastrointestinal dysmotility; voltage-gated potassium channel; voltage-gated sodium channel.