Short communication, Note

https://doi.org/10.24869/psyd.2018.216

CLINICAL EXOME SEQUENCING IN DEMENTIAS: A PRELIMINARY STUDY

Bojan Zalar ; University Psychiatric Clinic Ljubljana, Ljubljana, Slovenia
Aleš Maver ; Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia
Ana Kovanda ; Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia
Ana Peterlin ; Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia
Borut Peterlin ; Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia

Abstract

Background: Dementias are clinically and genetically heterogeneous group of neurodegenerative disorders. Often, dementias
with genetic etiology are clinically indistinguishable from non-genetic ones. The aim of this retrospective study was to evaluate the
yield of clinical exome sequencing in dementias, potentially associated with monogenic genetic predisposition.
Subjects and methods: For this purpose 20 consecutive patients younger than 65 years were studied in the period from January
2014 to December 2017; 14 with the diagnosis of Frontotemporal dementia (FTD), 3 with early-onset Alzheimer disease (EOAD)
and 3 with unspecified dementia. In addition to clinical exome sequencing including 57 genes associated with dementia, C9orf72
hexanucleotide expansion as tested in all patients.
Results: We found genetic etiology in 6 patients: 2 mutations in the PSEN1 gene (p.Pro264Ser and p.Phe105Cys) in the EOAD
patients, C9orf72 expansion and MAPT (c.1920+16C>T), mutation in the FTD group of patients as well as MAPT (c.1920+16C>T)
mutation and likely pathogenic mutation in the TYROBP mutation (p.Asp32Asn) in patients with unspecified diagnosis.
Conclusions: Our preliminary results imply significant diagnostic yield in identifying rare genetic causes of dementia,
combining comprehensive clinical exome sequencing and targeted C9orf72 expansion testing.

Keywords

dementia; exome sequencing; early-onset dementia; Alzheimer’s disease; frontotemporal dementia

Hrčak ID:

202237

URI

https://hrcak.srce.hr/202237

Publication date:

26.6.2018.

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