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  • Open Access

Glu89Gln transthyretin-related amyloidosis in Italy and Bulgaria: does geographic area influence phenotype beyond the shared mutation?

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Orphanet Journal of Rare Diseases201510 (Suppl 1) :P23

  • Published:


  • Cardiomyopathy
  • Amyloidosis
  • Geographic Origin
  • Ventricular Wall
  • Phenotypic Expression


Glu89Gln transthyretin (TTR) variant is a well-known cause of systemic amyloidosis with a cardiologic, neurologic or mixed phenotype. Even though Glu89Gln transthyretin (TTR) variant has been described worldwide, it remains unknown whether geographical area influences the phenotypic expression of the disease (as happens with the Val30Met mutation, which is known to manifest with different phenotypes in different geographical contexts). We hypothesized that significant phenotypic differences exist between patients with Glu89Gln-related amyloidosis according to the specific geographic origin.


We retrospectively analysed and compared the clinical, electrocardiographic and echocardiographic findings of 64 patients with Glu89Gln TTR-related amyloidosis from Italy and Bulgaria.


Despite a similar age at diagnosis of the disease (55 [52-60] years) patients in Bulgarian cohort have a mixed phenotype. A more severe left ventricular wall thickening was present in Bulgarian cohort compared to Italian one (17 [16-18] mm vs 15 [13-16], p=0.009) with a normal ejection fraction in all cases.


This is the largest series so far of patients with Glu89Gln TTR-related amyloidosis systematically analysed. Overall, disease onset is late with a mixed phenotypic expression. Despite a similar age at onset and a predominance of neurological routes, Bulgarian patients showed a more pronounced cardiomyopathy.

Authors’ Affiliations

Diagnostic and Specialty Medicine – DIMES, Alma Mater Studiorum, University of Bologna, Cardiology, 40138, Bologna, Italy
University Hospital Alexandrovska, Clinic of Cardiology, 1000 Sofia, Bulgaria
University Hospital Alexandrovska, Clinic of Neurology, 1000 Sofia, Bulgaria
Bellaria Hospital, Neurology, 40100 Bologna, Italy


© Gagliardi et al. 2015

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.