Childhood motor speech disorders: who to prioritise for genetic testing

Area of Science:

• Genetics
• Pediatrics
• Speech-Language Pathology

Background:

• Childhood motor speech disorders, including dysarthria and apraxia, have poorly understood etiologies.
• Previous research suggests a genetic component in these rare and severe speech disorders.
• No prior studies have evaluated the genetic diagnostic yield in a clinical setting for childhood apraxia of speech (CAS) and dysarthria.

Purpose of the Study:

• To investigate the genetic diagnostic yield for motor speech disorders in a clinical setting.
• To identify variables predictive of a genetic diagnosis in children with motor speech disorders.
• To compare the genetic diagnostic yield for motor speech disorders with conditions like epilepsy and cerebral palsy.

Main Methods:

• A cohort of 153 children with motor speech disorders underwent assessment by clinical geneticists and speech pathologists.
• Genomic testing included chromosomal microarray, Fragile X testing, and exome sequencing.
• Statistical analysis using odds ratios identified predictors of genetic diagnosis.

Main Results:

• A 29% diagnostic yield of pathogenic variants was observed in 44/153 children, including de novo variants.
• Predictors of genetic diagnosis included delayed walking, motor deficits, receptive language/cognitive impairment, and dysmorphism.
• CAS with dysarthria showed a higher genetic yield than CAS alone; autism spectrum disorder was less associated with genetic findings.

Conclusions:

• The clinical genetic diagnostic yield for motor speech disorders is comparable to epilepsy and cerebral palsy.
• Genomic testing should be considered routine for children with motor speech disorders, particularly those with co-occurring deficits.
• Prioritizing children with motor speech disorder and associated motor, language, or learning impairments for genomic testing is recommended.