Population diversity of the genetically determined TTR expression in human tissues and its implications in TTR amyloidosis.
Transthyretin (TTR) amyloidosis is a hereditary disease with a complex genotype-phenotype correlation. We conducted a literature survey to define the clinical landscape of TTR amyloidosis across populations worldwide. Then, we investigated whether the genetically determined TTR expression differs among human populations, contributing to the differences observed in patients. Polygenic scores for genetically determined TTR expression in 14 clinically relevant tissues were constructed using data from the GTEx (Genotype-Tissue Expression) project and tested in the samples from the 1,000 Genomes Project.



We observed differences among the ancestral groups and, to a lesser extent, among the investigated populations within the ancestry groups. Scandinavian populations differed in their genetically determined TTR expression of skeletal muscle tissue with respect to Southern Europeans (p = 6.79*10-6). This is in line with epidemiological data related to Swedish and Portuguese TTR Val30Met endemic areas. Familial amyloidotic cardiomyopathy (TTR deposits occur primarily in heart tissues) presents clinical variability among human populations, a finding that agrees with the among-ancestry diversity of genetically determined TTR expression in heart tissues (i.e., Atrial Appendage p = 4.55*10-28; Left Ventricle p = 6.54*10-35).



Genetically determined TTR expression varied across human populations. This might contribute to the genotype-phenotype correlation of TTR amyloidosis.
Department of Biology, University of Rome Tor Vergata, Rome, Italy.
Andrea
A
Iorio
Department of Biology, University of Rome Tor Vergata, Rome, Italy.
Flavio
F
De Angelis
Clinical Pathophysiology Center, AFaR Foundation - "San Giovanni Calibita" Fatebenefratelli Hospital, Isola Tiberina, Rome, Italy.
Marco
M
Di Girolamo
Departments of Geriatrics, Neurosciences & Orthopedics, Institute of Neurology, Catholic University of the Sacred Heart, Fondazione Policlinico Universitario A. Gemelli, Rome, Italy.
Marco
M
Luigetti
Division of Neurology and Neurorehabilitation, San Giuseppe Hospital, IRCCS-Istituto Auxologico Italiano, Piancavallo (VB), Italy.
Luca G
LG
Pradotto
Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy.
Anna
A
Mazzeo
Genetic Diagnostics Unit, Laboratory Department, Careggi University Hospital, Florence, Italy.
Sabrina
S
Frusconi
Division of Neurology, "Vito Fazzi" Hospital, Lecce, Italy.
Filomena
F
My
Clinical Pathophysiology Center, AFaR Foundation - "San Giovanni Calibita" Fatebenefratelli Hospital, Isola Tiberina, Rome, Italy.
Dario
D
Manfellotto
Department of Biology, University of Rome Tor Vergata, Rome, Italy.
Maria
M
Fuciarelli
Department of Psychiatry, Yale University School of Medicine and VA CT Healthcare Center, VA CT 116A2, 950 Campbell Avenue, West Haven, CT, 06516, USA. renato.polimanti@yale.edu.
Renato
R
Polimanti
D000686:Amyloidosis / Q000235:genetics* / Q000473:pathology*; D005786:Gene Expression Regulation; D005838:Genotype; D006801:Humans; D010641:Phenotype; D011228:Prealbumin / Q000235:genetics*
D011228:Prealbumin
Amyloid; Gene expression; Genotype-phenotype correlation; Mutation; Transthyretin