Don’t undertake sequential testing for heterogeneous genetic disorders when targeted next generation sequencing (NGS) is available
A heterogeneous genetic disorder is one where the same disease or condition can be caused, or contributed to, by a number of different genes. The traditional strategy for genetic testing involves sequential sequencing of individual genes, selected according to the patient’s clinical presentation and family history. By contrast, next generation sequencing (NGS) involves the sequencing of millions of small fragments of DNA at the same time. Reductions in the cost of NGS now make it a more attractive solution for clinical diagnostic testing to identify the disease-causing mutation(s) in patients with genetically heterogeneous disorders than traditional sequential testing. In particular, the targeted NGS approach which restricts analysis to genes known to be implicated in a particular phenotype has been also successfully applied to heterogeneous disorders such as inherited peripheral neuropathy (IP).
- Antoniadi T, Buxton C, Dennis G, et al. Application of targeted multi-gene panel testing for the diagnosis of inherited peripheral neuropathy provides a high diagnostic yield with unexpected phenotype-genotype variability. BMC Medical Genetics 2015;16:84.
- Ellard S, Lindsay H, Camm N, et al. Practice guidelines for targeted next generation sequencing analysis and interpretation. Association for Clinical Genetic Science, 2014.
A preliminary list was developed by the Lead Fellow which was then distributed to all the clinical geneticists in Australia who are all members of the Australasian Association of Clinical Geneticists (AACG), a special interest group of the HGSA. Following feedback the topic was revisited at a meeting of this group during the annual scientific conference of the HGSA, after which the list was finalised.
- 1 Don’t use brain magnetic resonance imagery (MRI) for routine surveillance of asymptomatic neurofibromatosis type 1
- 2 Don’t undertake sequential testing for heterogeneous genetic disorders when targeted next generation sequencing (NGS) is available
- 3 Don’t undertake genetic testing for methylenetetrahydrofolate reductase (MTHFR), apolipoprotein E (APOE) and other such tests where the clinical utility for diagnostic purposes is extremely low
- 4 Don’t undertake carrier state testing for rare recessive disorders where a partner has a family history, the couple is non-consanguineous and there are no common causative mutations.
- 5 Don’t undertake genetic testing when clinical diagnostic criteria exist and there are no reproductive or predictive testing implications.