Professor Angela Morgan is head of speech and language at the Murdoch Children’s Research Institute and Professor of Speech Pathology at the University of Melbourne and was the recipient of the 2020 NHMRC Elizabeth Blackburn Investigator Grant Award (Leadership in Clinical Medicine and Science).
Speech is a uniquely human skill. The ability to communicate underpins every aspect of our daily lives as humans. From birth, our trajectory and success in speech development is a core predictor for later literacy skills, educational attainment, employment opportunities, and ultimately, quality of life. Yet as a community, we generally take speech ability for granted, and we rarely stop to consider the true impact of a speech disorder on a child or family.
From a young age, I was struck by the inequities that significant speech disorders caused for those around me. At high school on the north-west coast of Tasmania, in particular, I was surrounded by children with communication disability. Children with severe speech disorders such as apraxia of speech, stuttering or dysarthria, experienced extreme anxiety, limited friendships and social isolation. Impacts on academic ability were also striking. Severe speech disorders place an individual at three times the risk for literacy impairment and 70 per cent of individuals with communication impairment end up unemployed or in the lowest income brackets.
Parents of children with severe speech disorders also experience anxiety, isolation, and feelings of inadequacy as a parent, as extended family and well-meaning friends try to give advice on how to teach their child to talk; a skill that is usually considered to be an innately programmed, unstoppable force. But not for everyone.
As a child in the 1980s, I spent a lot of time wondering why some of my peers had speech and language disorders and whether there was more that could be done to support their development. The only aetiologies for speech and language disorders that were well understood at that time were acquired brain injury, long-standing genetic syndromes (eg. Down syndrome) or hearing impairment. Another part of the aetiological puzzle seemes to be that some children with neurodevelopmental disorders such as autism, intellectual disability or epilepsy also had speech and language disorders. Yet even into the 90s during my academic training, there was little interest in the comorbidities of speech and language and always an assumption that communication difficulties were secondary to co-existing conditions, rather than being central to the overall profile. The company speech and language disorders kept was not thought to be of very much relevance to their diagnosis nor management.
These questions, formed early in my childhood, still drive my research today. Over the past ten years, our team have shown that single gene aetiologies explain 30 per cent of cases of severe speech disorder in children and across languages. Our team have also shown that many of the ‘genes for speech’ are genes associated with other neurodevelopmental conditions with varying levels of co-occurring speech and language impairment. That is, a gene that has been associated with epilepsy, ID or autism in one child, may also be associated with speech disorder either with or without these conditions in another child. This finding of diverse or overlapping phenotypes derived from the same gene change is common across all genetic-based neurodevelopmental disorders, yet had not previously been shown to be relevant to speech and language disorders. Careful phenotyping, paired with new developments in gene sequencing and analysis methods, has led to identification of tens of novel genes explanatory for speech disorder and to a greater understanding of how speech disorders interact with other disorders of neurodevelopment.
Identification of ‘genes for speech’ has been significant for affected children and families. Being able to explain the ‘why’ for a child and family who have put in many years of expensive and burdensome speech therapy, sometimes with little impact, has been life changing for many families. Understanding ‘why’ alleviates unwarranted feelings of guilt (was it something I did during pregnancy?) and ends the diagnostic journey of often non-informative and sometimes invasive, tests and specialist appointments. With a burgeoning number of, and better understanding of, single gene conditions, our work has enabled families to identify with others affected by the same genetic condition, globally. The sense of belonging to single gene support groups, such as the Koolen de Vries Syndrome Foundation for children with KANSL1-related condition or SETBP1 society for those with SETBP1 haploinsufficiency disorder is life changing, with this sense of relatedness being linked to positive, lasting, and significant interpersonal relationships.
Our team are focused on providing more aetiological, diagnostic and prognostic information to children and families with severe speech disorder. As well as continuing our gene discovery work, we also take a ‘genes first’ approach in studying speech and language abilities in children with known rare genetic syndromes. When a child is born with a genetic condition, there is rarely information to explain whether a child will develop speech and if so, whether they will ever develop age-appropriate speech ability. Families with novel rare genetic conditions have no prognostic data to inform whether they will ever hear their child say first words or speak well enough to harness education and attend mainstream school. Our team are working to better understand the natural history and prognosis for these genetic-based speech conditions and to provide educational and support packages for affected children, families and clinicians working with children with severe speech disorder. Into the future, greater understanding of the biological bases of these conditions will lead to precision therapies.
Professor Morgan with Professor Sharon Lewin and Professor Ingrid Scheffer at the Research Excellence Awards.
The Elizabeth Blackburn Investigator Grant Awards are named to honour the Australian Nobel Laureate Professor Elizabeth Blackburn AC FRS FAA FRSN, a molecular biologist who received the Nobel Prize in Physiology or Medicine in 2009 jointly with Professor Jack Szostak and Professor Carol Greider for the discovery of how chromosomes are protected by telomeres and the enzyme telomerase. The awards were established to promote and foster the career development of female researchers and are awarded annually to the highest ranked female applicant (Leadership category) in each of the Basic Science, Clinical Medicine and Science, Public Health and Health Services research areas of the Investigator Grants scheme.
The full list of Research Excellence Awards recipients announced in 2020 is available on NHMRC's website.