Genetic testing in ALS: A survey of current practices

Objective: to determine the degree of consensus among clinicians on the clinical use of genetic testing in ALS and the factors that determine decision making.

Methods: ALS researchers worldwide were invited to participate in a detailed online survey to determine their attitudes and practices relating to genetic testing.

Results: Responses from 167 clinicians from 21 different countries were analysed. The majority of respondents (73.3%) do not consider that there is a consensus definition of FALS. 57% consider a family history of FTD and 48.5% the presence of a known ALS genetic mutation as sufficient for a diagnosis of FALS. Most respondents (90.2%) offer genetic testing to patients they define as having FALS and 49.4% to patients with sporadic ALS. Four main genes (SOD1, C9ORF72, TARDBP and FUS) are commonly tested. 55.2% of respondents would seek genetic testing if they had personally received a diagnosis of ALS. 42% never offer pre-symptomatic testing to family member of patients with FALS. Responses varied between ALS specialists and non-specialists and based on the number of new patients seen per year.

Conclusions: There is a lack of consensus amongst clinicians as to the definition of FALS. Significant variation exists in attitude and practices related to genetic testing of patients and pre-symptomatic testing of their relatives across geographic regions, and between experienced specialists in ALS and non-specialists.