C9orf72 hexanucleotide repeat expansion (HRE), the most common genetic cause underlying frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS), is a complex genetic alteration that cannot be detected using genome wide association studies. Annakaisa Haapasalo, PhD, University of Eastern Finland, Joensuu, Finland, talks on the identification of single nucleotide polymorphisms (SNPs) that may act as markers of C9orf72 HRE and facilitate early detection of expansion carriers. Using data from a large genetic database, the SNP rs139185008 was found to be associated with validated C9 expansion carriers. Following this, the SNP was studied in the FinnGen database to assess its ability to identify potential C9orf72 HRE carriers. The analysis revealed that rs3849942 was most strongly associated with a diagnosis of FTLD and ALS. Dr Haapasalo notes that the identified carriers of the SNP rs139185008 need to be directly phenotyped to evaluate its full potential as a marker of C9orf72 HRE. This interview took place at the Harvard European Alumni Training Network (HEAT-Net) 2021 meeting.
