Human Genetics Society of Australasia

The Human Genetics Society of Australasia (HGSA) was formed in 1977 to provide a forum for the various disciplines collected under the title of human genetics.

The Society has reviewed the evidence and consulted with its expert members to develop the following recommendations to support best patient care and reduce the use of unnecessary or ineffective practices within a given clinical context.

Download the Human Genetics Society of Australasia's Top-5 recommendations (PDF)

Top-5 recommendations on low-value practices

1. Don’t use brain magnetic resonance imagery (MRI) for routine surveillance of asymptomatic neurofibromatosis type 1.

Rationale and evidence

Rationale

Neurofibromatosis type I (NF-1) is a tumour disorder caused by the mutation of a gene on chromosome 17 that is responsible for control of cell division. It causes tumours along the nervous system that can grow anywhere in the body. Routine screening investigations are not recommended for the detection of the majority of complications associated with the condition. Baseline brain and spine MRI, and routine imaging of the chest and abdomen to identify asymptomatic tumours, do not influence management and should not be undertaken.

Evidence

Ferner RE, Huson SM, Thomas N, et al. Guidelines for the diagnosis and management of individuals with neurofibromatosis 1. Journal of Medical Genetics. 2007; 44:81-88.


2. Do not undertake sequential testing for heterogenous genetic disorders when targeted next generation sequencing (NGS) is available.

Rationale and evidence

Rationale

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 (IPN).

Evidence

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. Practice guidelines for Targeted Next Generation Sequencing Analysis and Interpretation. Association for Clinical Genetic Science Guidelines, May 2014.


3. Do not undertake genetic testing for methylenetetrahydrofolate reductase (MTHFR), apolipoprotein E (APOE) and other such tests where the clinical utility for diagnostic purposes is extremely low.

Rationale and evidence

Rationale

While genetic testing can help indicate susceptibility to particular genetic conditions, there are some conditions where the presence of particular alleles is neither necessary nor sufficient to cause the condition or where the alleles have a higher prevalence in the general population than the condition itself. This is the case for instance with apolipoprotein E as a genetic marker for Alzheimer’s disease and methylenetetrahydrofolate as a marker for venous thromboembolism.

Evidence

Goldman JS, Hahn SE, Catania JW, et al. Genetic counseling and testing for Alzheimer disease: Joint practice guidelines of the American College of Medical Genetics and the National Society of Genetic Counselors. Genetic Medicine. 2011; 13(6): 597-605.

Hickey SE, Curry CJ & Toriello HV. ACMG Practice Guideline: lack of evidence for MTHFR polymorphism testing. Genetic Medicine. 2013; Feb 15(2): 153-6.


4. Do not 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.

Rationale and evidence

Rationale

With a rare recessive disorder, although the individual with the family history will have an increased risk of being a carrier, their unrelated partner will have a low general population risk. Therefore, their a priori combined risk of having a child with this rare recessive condition will generally be less than 1%. If the gene has no known common disease causative mutations then testing the unrelated partner for carrier status has low sensitivity and specificity.

Evidence

Meikle PJ, Hopwood JJ, Clague AE, Carey WF. Prevalence of lysosomal storage disorders. JAMA. 1999; 20: 281(3): 249-54.


5. Do not undertake genetic testing when clinical diagnostic criteria exist and there are no reproductive or predictive testing implications.

Rationale and evidence

Rationale

Like other screening or diagnostic tests, genetic tests do not have inherent utility. It is the adoption of therapeutic or preventive interventions that influences health outcomes. If clinical diagnostic criteria already exist for the condition in question and there are no reproductive or other predictive testing implications as a result of definitively identifying a genetic cause for the condition, then this renders genetic testing unnecessary.

Evidence

Ferner RE, Huson SM, Thomas N, et al. Guidelines for the diagnosis and management of individuals with neurofibromatosis 1. Journal of Medical Genetics. 2007; 44: 81-88.

 

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