Objective: To investigate spoken language comprehension (SLC), speech and functional communication in GNAO1-associated disorder (GNAO1-AD).

Background: GNAO1-AD is ultra-rare and clinically heterogeneous. Often, children with GNAO1-AD have (severe) motor impairments. Assessment of SLC using conventional tests may be challenging, as this usually requires the child to complete a motor task. This leads to an underestimation of communication skills, which may lead to inadequate support, feelings of frustration or even (social) isolation.

Method: SLC and functional communication were assessed using the Computer-Based instrument for Low motor Language Testing (C-BiLLT) and the Communication Function Classification System (CFCS, classifying functional communication), respectively. The C-BiLLT, specifically developed for persons with speech and motor impairments, incorporates alternative access methods for communication, including eye-tracking systems and wheelchair head-controls. It is a norm-referenced test, based on a large norm data of  typically developing children. Disease severity and motor functions were assessed using the GNAO1-Severity Scale, Gross Motor Function Classification System (GMFCS), Manual Ability Classification System (MACS) and Viking Speech Scale (VSS).

Results: Three girls and six boys with GNAO1-AD were included (median age: 11 years; range: 3-14) [table1]. Median C-BiLLT score was 0-76 (max score = 87) [figure1]. A strong, negative correlation was found between C-BiLLT raw scores and levels of CFCS (r_s(7) = -0,688, p = 0.040), indicating that better SLC correlated with better functional communication [figure2]. No significant associations were found between C-BiLLT scores and GNAO1-Severity Scale scores, GMFCS, MACS or VSS levels.

Conclusion: This study shows considerable heterogeneity of communication performance in children with GNAO1-AD. Children with better SLC communicate more effectively in daily life. The level of SLC, however, was not related to the severity of motor impairments. These findings underline the need for tailored approaches to support communication in daily life. Additionally, we stress the importance of assessment instruments suitable for children with motor disabilities, such as the C-BiLLT, as they are vital in standard of care for paediatric movement disorders.

Patient characteristics

Raw scores and chronological age

Functional communication, speech and SLC

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MDS Abstracts - https://www.mdsabstracts.org/abstract/exploring-the-variability-in-spoken-language-comprehension-speech-and-functional-communication-in-children-with-gnao1-associated-disorder-a-case-series/