Clinical Actionability of Genetic Findings in Cerebral Palsy: A Systematic Review and Meta-Analysis.

Abstract

IMPORTANCE: Single gene variants can cause cerebral palsy (CP) phenotypes, yet the impact of genetic diagnosis on CP clinical management has not been systematically evaluated. OBJECTIVE: To evaluate how frequently genetic testing results would prompt changes in care for individuals with CP and the clinical utility of precision medicine therapies. DATA SOURCES: Published pathogenic or likely pathogenic variants in OMIM genes identified with exome sequencing in clinical (n = 1345) or research (n = 496) cohorts of CP were analyzed. A systematic literature review for evidence of effective therapies for specific genetic etiologies was performed. STUDY SELECTION: Nonstandard interventions that led to a detectable improvement in a defined outcome in individuals with variants in the gene of interest were included. DATA EXTRACTION AND SYNTHESIS: Literature was evaluated using PRISMA guidelines. A diverse, expert working group was established, scoring rubrics adapted, and scoring consensus built with a modified Delphi approach. MAIN OUTCOMES AND MEASURES: Overall clinical utility was calculated from metrics assessing outcome severity if left untreated, safety and practicality of the intervention, and anticipated intervention efficacy on a scale from 0 to 3. RESULTS: Of 1841 patients with CP who underwent exome sequencing, 502 (27%) had pathogenic or likely pathogenic variants related to their phenotype. A total of 243 different genes were identified. In 1841 patients with identified genetic etiologies of CP, 140 (8%) had a genetic etiology classified as actionable, defined as prompting a change in clinical management. Also identified were 58 of 243 genes with pathogenic or likely pathogenic variants with actionable treatment options: 16 targeting the primary disease mechanism, 16 with specific prevention strategies, and 26 with specific symptom management. The level of evidence was also graded according to ClinGen criteria; 45 of 101 interventions (44.6%) had evidence class D or below. The potential interventions have clinical utility with 98 of 101 outcomes (97%) being moderate-high severity if left untreated and 63 of 101 interventions (62%) predicted to be of moderate-high efficacy. Most interventions (72 of 101 [71%]) were considered moderate-high safety and practicality. CONCLUSIONS AND RELEVANCE: The findings indicate that actionable genetic findings occurred in 8% of individuals referred for genetic testing with CP. Evaluation of potential efficacy, outcome severity, and intervention safety and practicality indicates moderate-high clinical utility of these genetic findings. Genetic sequencing can identify precision medicine interventions that provide clinical benefit to individuals with CP. The relatively limited evidence base underscores the need for additional research.