Garvan researchers help establish new test for genetic kidney disease

A team of researchers from the Garvan Institute of Medical Research and St Vincent’s Hospital have demonstrated the validity of a new method of testing for autosomal dominant polycystic kidney disease (ADPKD) using whole genome sequencing.

The research findings were recently profiled by PKD Australia and the test is now available through Genome.One.

ADPKD is an inherited and currently incurable disorder affecting more than 1 in 1000 Australians, in which cysts progressively expand and destroy the kidneys, eventually causing renal failure. Earlier diagnosis can help guide management of the disease, predict prognosis and inform selection of living kidney donors for kidney transplantation.

Testing for the condition using traditional gene sequencing methods is complicated by six “pseudogenes”, which are non-functional genes that are almost identical in DNA sequence to the causative gene, and are located right next to them in the genome.

PKD Australia last year awarded a seed grant to Dr Amali Mallawaarachchi (pictured), a genomics researcher in the Genomics and Epigenetics Division at the Garvan, and a team of clinicians and scientists from Garvan’s Kinghorn Centre for Clinical Genomics and St. Vincent’s Hospital to develop a new whole genome sequencing test for the condition. The research team also included Professor John Shine, Dr Timothy Furlong, Dr Mark Cowley and Yvonne Hort.

The research team partnered with the Mayo Clinic in the US to compare the results of a cohort of ADPKD patients who had undergone diagnostic testing using traditional gene sequencing methods with results using the whole genome sequencing (WGS) method.

Their findings showed that the WGS method was as accurate at diagnosing the condition as the traditional gene sequencing tests, but required less laborious laboratory preparation and was better able to detect gene deletions, duplications and structural variants.

Dr Mallawaarachchi said the research was a valuable step in accrediting the first diagnostic genetic test for ADPKD in Australia.

The new testing method would allow patients to be diagnosed sooner, help family planning and living kidney donor decisions, help predict prognosis and, in the long term, could accelerate understanding of the underlying cause of ADPKD – an important step in finding a cure, she said.

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