**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Milou Berends
Department of Internal Medicine
University Medical Center Groningen, Amyloidosis Center of Expertise
Groningen, the Netherlands

**Main Body of the Abstract**
Background: Genetic testing may be useful in individuals with suspected cardiac amyloidosis. This study aims to establish the diagnostic yield of early gene panel testing.
Method: All consecutive patients with suspected cardiac amyloidosis without a known familial genetic variant for amyloidosis referred to the University Medical Center Groningen, the Netherlands, between 2017-2023 were enrolled. Patients underwent genetic testing using a gene panel, irrespective of their Perugini grade cardiac tracer uptake.
Results: 219 unrelated patients underwent genetic testing. Eleven(5%) had a pathogenic variant. Seven had hereditary transthyretin amyloidosis (ATTRv), four had a pathogenic variant in another gene (APOC2, GSN, APOA1, OSMR). Mass spectrometry typing of amyloid showed ATTR amyloid in the APOC2 carrier. There were no extracardiac symptoms associated with the mutated GSN gene. Therefore these two patients were diagnosed with wildtype ATTR (ATTRwt). All these ATTRv and ATTRwt patients had Perugini grade 2-3. One patient with a pathogenic APOA1 variant, consistent with mass spectrometry typing, had Perugini grade 1. One patient had a pathogenic OSMR variant and Perugini grade 0 without disease manifestations associated with the mutated OSMR gene (Figure 1).
Conclusion: The yield of genetic testing in patients with suspected cardiac amyloidosis was 5%. Genetic testing may be helpful in cases with suspected amyloidosis and Perugini grade 0-1. Although gene panel testing revealed two rare non-TTR pathogenic variants (APOC2, GSN) among patients with Perugini grade 2-3, these patients were diagnosed with ATTRwt, suggesting that genetic testing of TTR is sufficient for patients with Perugini grade 2-3 in our population.



**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Milou Berends
Department of Internal Medicine
University Medical Center Groningen, Amyloidosis Center of Expertise
Groningen, the Netherlands

**Main Body of the Abstract**
**Background:** Genetic testing may be useful in individuals with suspected cardiac amyloidosis. This study aims to establish the diagnostic yield of early gene panel testing.
**Method:** All consecutive patients with suspected cardiac amyloidosis without a known familial genetic variant for amyloidosis referred to the University Medical Center Groningen, the Netherlands, between 2017-2023 were enrolled. Patients underwent genetic testing using a gene panel, irrespective of their Perugini grade cardiac tracer uptake.
**Results:** 219 unrelated patients underwent genetic testing. Eleven(5%) had a pathogenic variant. Seven had hereditary transthyretin amyloidosis (ATTRv), four had a pathogenic variant in another gene (_APOC2, GSN, APOA1, OSMR_). Mass spectrometry typing of amyloid showed ATTR amyloid in the _APOC2_ carrier. There were no extracardiac symptoms associated with the mutated _GSN_ gene. Therefore these two patients were diagnosed with wildtype ATTR (ATTRwt). All these ATTRv and ATTRwt patients had Perugini grade 2-3. One patient with a pathogenic _APOA1_ variant, consistent with mass spectrometry typing, had Perugini grade 1. One patient had a pathogenic _OSMR_ variant and Perugini grade 0 without disease manifestations associated with the mutated _OSMR_ gene (Figure 1).
**Conclusion:** The yield of genetic testing in patients with suspected cardiac amyloidosis was 5%. Genetic testing may be helpful in cases with suspected amyloidosis and Perugini grade 0-1. Although gene panel testing revealed two rare non-_TTR_ pathogenic variants (_APOC2, GSN)_ among patients with Perugini grade 2-3, these patients were diagnosed with ATTRwt, suggesting that genetic testing of _TTR_ is sufficient for patients with Perugini grade 2-3 in our population.



Diagnostic yield of multigene panel analysis in patients with suspected cardiac amyloidosis PB42 (#473)

We invite you to attend the XIX International Symposium on Amyloidosis to be held in Rochester, MN.

This symposium is organized as a hybrid meeting (with the focus on in-person) held from Sunday, May 26 through Thursday, May 30, 2024.

Together with the ISA Board and members of Mayo Clinic, a very attractive scientific hybrid program is being planned. The program will cover a variety of types of systemic amyloidosis: ATTR (hereditary and wild-type), AL (light-chain), AA and less frequent forms. There will be key lectures, specific symposia including those company sponsored, oral presentations and poster sessions of accepted abstracts.

COURSE DESCRIPTION
This program will provide a comprehensive review of state-of-the-art education in systemic amyloidosis: basic science, pathophysiology, diagnosis, current and emerging treatments. Scientific presentations will include competitive oral and poster abstracts. The rapid evolution of scientific discovery and expanding treatment options has created tremendous interest in the field and this meeting will fill and important gap in educating scientists and clinicians.