Individuals with rare genetic conditions may experience a delay or loss of developmental skills. Many have limited verbal speech. The aim of this clinical trial is to examine how well a speech-generating device supports the communication skills of participants with a rare genetic condition. The speech-generating device is a communication program loaded onto an iPad.

This is a crossover trial, meaning that each participant will receive both the treatment (device) and a control (usual care; no device) phase. The order in which each participant receives the device versus the usual care (no device) will depend on which group the participant is assigned to. The changes in communication in each phase will then be compared.

During the trial, participants can expect to complete a series of assessments and attend a total of 2 x 1-hour therapy session per week for 6 weeks.

In Australia, a disease is considered rare if it affects less than 1 in 2,000 individuals. There are over 7,000 rare genetic conditions, with three quarters affecting children. Rare diseases are often serious and progressive, presenting with ongoing health and developmental challenges, including speech and language disorders.

Augmentative and alternative communication (AAC) is one of the ways to support children with little speech and children with rare genetic conditions should have access to such tools as early as possible to maximise learning opportunities. However, the efficacy of high-tech AAC methods, such as speech generating devices, for children with rare genetic conditions have not been rigorously examined.

In this randomised cross-over trial, 38 participants with a rare genetic condition will be randomised into two groups (n=19 per group), which will determine the sequence of treatment delivery. The primary aim of this trial is to evaluate the efficacy of implementing a speech-generating device on communication outcomes compared with their usual care (i.e. no device). Change in communication will be measured using a patient-defined outcome - this outcome is a 'communicative act' chosen at the beginning of the trial with participants and their family. This means that each participant will have an individualised communication outcome which will be targeted during treatment sessions and measured in assessment sessions. The secondary aims include parent-reported communication, family impact and language/communication competence.

Each participant will complete screening, preference testing and baseline assessments about 2-4 weeks before randomisation. Further assessments will be completed before and after each phase. For each participant, the change in assessment scores between the start and the end of each period will be calculated. The mean difference in the change in total score between the two periods will then be calculated.

Each participant is expected to be involved in the study for 12 weeks after randomisation. This is split into two phases (6 weeks each). In the treatment (device) phase, each participant will receive two 1-hour therapy sessions per week, for 6 weeks, with a communication device (or 12 x 1-hour therapy within a 6-week treatment phase). The device is implemented by a qualified speech pathologist on the project team and can occur at Murdoch Children's Research Institute or at the participants' home.

The control (usual care) phase involves another 6 weeks, however, no therapy sessions are provided by the project team. Weekly phone-call or telehealth check-ins will be performed to ensure things are going smoothly.

Inclusion Criteria:

• Is between the ages of 3 and 12 years, inclusive, at the time of enrolment
• Has a diagnosis of a rare genetic disorder
• Passes a visual-motor screening test, therefore being able to tap on an iPad spontaneously or by imitation and has adequate hearing
• Considered "minimally verbal" with less than 50 spontaneous words (or gestalts) at baseline assessments, confirmed with the LVIS.
• Is not currently using a speech-generating device with proficiency (i.e. using the device as a main mode of communication on a daily basis).
• Is English-speaking or consents to therapy being conducted in English (parents will need to be able to complete the parent-reported measures in English)

Exclusion Criteria:

• Has an additional or dual genetic variation (as this is likely to cause multiple complications and increase variability),
• Is extremely ill or has progressed into a later stage of their disease (i.e. child has clinically significant loss of vision, hearing, fine motor skills, or is unable to adequately attend sessions due to illness),
• This is to ensure treatment is beneficial, reduce harm and reduce attrition rates.
• Lives outside of the state of Victoria (making it difficult for in-person appointments)
• Inability or unwillingness of participant or legally acceptable representative to give written informed consent.

The de-identified data set collected for the analysis of this trial will be made available 12 months following analysis and publication of the primary outcome. The following will be made available long-term for use by future researchers from a recognised research institution:

• Individual participant data that underlie the results reported after anonymisation/deidentification (text, tables, figures and appendices),
• Trial protocol, Participant Information and Consent Form (PICF),
• Statistical Analysis Plan (SAP), statistical code. Note that the data sharing of de-identified speech and language data is an Optional Consent for participants.

12 months after publication of primary outcome

Interested researchers may request access to the data by submitting a formal data sharing request to the Sponsor. The request will be reviewed by the Sponsor and the Sponsor-Investigator, and any relevant Murdoch Children's Research Institute (MCRI) data sharing committee, considering factors such as scientific merit, data security, and adherence to the approved research objectives. The data may be obtained from MCRI by emailing mctc@mcri.edu.au

As well as the outcome assessments, research assistants completing coding/rating and integrity/reliability assessments will be blinded.