Caregivers' Perceptions of Clinical Symptoms, Disease Management, and Quality of Life Impact in Cases of Cyclin-Dependent Kinase-Like 5 Deficiency Disorder: Cross-Sectional Online Survey.

Abstract

Background: Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is an ultrarare genetic condition causing developmental epileptic encephalopathy characterized by seizures and motor and intellectual disabilities. No disease-modifying therapies are available, and treatments focus mainly on symptom management to improve quality of life.

Objective: The aim of this study was to better understand the burden of CDD based on family caregivers' perceptions.

Methods: The study was a cross-sectional, web-based survey comprising 40 questions for caregivers of patients with CDD and focusing on sociodemographic and medical characteristics, disease burden, unmet needs, treatments, and support. An adapted version of the EQ-5D-5L instrument was included to measure patients' health-related quality of life as perceived by their caregivers.

Results: A total of 132 caregivers, mostly from western parts of Europe, responded. The median patient age was 7.6 (IQR 2.9-12.2) years. Seizure onset occurred early, with the median onset at 2.0 (IQR 1.0-3.0) months of age. The median age at diagnosis was 1.2 (IQR 0.6-4.0) years. Epilepsy (123/132, 93.2%) and limited communication skills (111/132, 84.1%) were the most commonly reported symptoms. The highest number of different types of symptoms was reported for patients aged 5-9 years, with a median of 9.0 (IQR 7.5-10.0) symptoms. Most patients with epilepsy experienced daily seizures (81/123, 65.9%), and nearly all (119/123, 96.7%) were on antiseizure medications. A minority was on a ketogenic diet (21/123, 17.1%) or underwent vagus nerve stimulation (14/123, 11.4%). The care received was multidisciplinary. Compared to younger patients, adults had fewer medical appointments and a smaller variety of health care professionals in their care team. The EQ-5D-5L, adapted for caregivers, indicated low health-related quality of life for patients, with a median global index value of 0.18 (IQR 0.11-0.32). The most severe consequences of CDD on patients' daily lives were reported for mobility (88/132, 66.7%), self-care (120/132, 90.9%), and everyday activities (103/132, 78.0%). Caregiver burden was also substantial, with all life aspects reportedly impacted by CDD, including professional life and financial resources (median impact ratings of 9.0/10 and 7.0/10, respectively). Access to support and care varied depending on location. Caregivers outside Europe reported a longer time between the first seizure and diagnosis (26.5, IQR 3.2-47.0 months) compared to European caregivers (11.0, IQR 5.0-45.0 months). They also reported a higher impact of CDD on their financial resources (rating of 10/10) compared to European caregivers (rating of 6/10) and greater challenges in covering costs.

Conclusions: The study findings provide valuable insights on symptoms and disease burden related to CDD. This burden was quantitatively characterized with the EQ-5D-5L for the first time and was perceived as substantial by family caregivers. Discrepancies between geographic regions and age groups were highlighted, especially regarding available support and access to resources and care.