Genomic testing can end diagnostic odysseys for patients with complex neurological and neurodegenerative diseases
February 23, 2021
A Melbourne Genomics study published in the Journal of Neurological Sciences found that genomic testing is a valuable diagnostic tool for a range of complex neurological diseases.
Study leads Dr Dhamidhu Eratne and Professor Samuel Berkovic investigated whether genomic sequencing – combined with extended bioinformatics repeat expansion analysis – can provide a quicker, more accurate diagnosis in conditions including ataxia, early-onset dementia, spastic paraparesis, Parkinson’s disease, dystonia, motor neurone disease and complex or not-otherwise-specified disease.
Of the 160 patients tested in the study, 21% received a genetic diagnosis, with the highest rates in patients with spastic paraparesis (40%), ataxia (25%) and complex, not-otherwise-specified conditions (26%).
Bioinformatic analysis that detects repeat expansions – which is not yet routinely utilised in clinical settings – resulted in an unexpected additional diagnosis with a rare clinical presentation, highlighting the utility of complementary technologies in care.
“Diagnosis of complex neurological and neurodegenerative conditions typically takes years, three to five if not longer, and this ‘diagnostic odyssey’ can involve multiple assessments, misdiagnoses, and costly and invasive medical procedures,” said lead author Dr Dhamidhu Eratne of The Royal Melbourne Hospital.
“For many patients, an earlier, accurate genetic diagnosis, would have saved substantial healthcare costs and enabled accurate genetic counselling; prenatal, preimplantation and family genetic testing options; and most importantly, improved outcomes for patients and families. The median duration of symptoms in our cohort was nine years. Many patients had longer, even decades of symptoms.”
Despite most participants having long ‘diagnostic odysseys’, the study still found impacts on care from genomic testing in approximately two thirds of diagnosed patients.
“Earlier diagnosis could have not only spared a great deal of uncertainty, distress and costs but for several patients, specific, tailored interventions based on the genetic diagnosis could have significantly improved symptoms, progression of the illness and outcomes,” said Dr Eratne.
“Genomic testing has and – if made available – will make a difference to patients with complex neurological disease.”
The study received almost 250 referrals in approximately 12 months, indicating high interest, clinical need and demand amongst neurologists, neuropsychiatrists, geneticists, and their patients.
The complex neurological and neurodegenerative diseases study, published in the Journal of Neurological Sciences, was a multidisciplinary collaboration between Austin Health, The Royal Melbourne Hospital, The Royal Children’s Hospital, Monash Health and WEHI, under the auspices of Melbourne Genomics Health Alliance, funded by the State Government of Victoria.
Complex neurological and neurodegenerative diseases are one of 16 areas of health investigated by Melbourne Genomics, and patients in this study were among more than 3,800 adults and children who have received genomic testing since 2014.