Tatiana Prokaeva, Elena S Klimtchuk, Polina Feschenko, Brian Spencer, Haili Cui, Eric J Burks, Roshanak Aslebagh, Khaja Muneeruddin, Scott A Shaffer, Elizabeth Varghese, John L Berk, Lawreen H Connors
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引用次数: 0
Abstract
Background: The amyloidogenic transthyretin (TTR) variant, V122I, occurs in 4% of the African American population and frequently presents as a restricted cardiomyopathy. While heterozygosity for TTR V122I predominates, several compound heterozygous cases have been previously described. Herein, we detail features of ATTRv amyloidosis associated with novel compound heterozygous TTR mutation, T60I/V122I and provide evidence supporting the amyloidogenecity of T60I.
Methods: A 63-year-old African American female presented with atrial fibrillation, congestive heart failure, autonomic and peripheral neuropathy. In vitro studies of TTR T60I and V122I were undertaken to compare the biophysical properties of the proteins.
Results: Congophilic deposits in a rectal biopsy were immunohistochemically positive for TTR. Serum screening by isoelectric focussing revealed two TTR variants in the absence of wild-type protein. DNA sequencing identified compound heterozygous TTR gene mutations, c.239C > T and c.424G > A. Adipose amyloid deposits were composed of both T60I and V122I. While kinetic stabilities of T60I and V122I variants were similar, distinct thermodynamic stabilities and amyloid growth kinetics were observed.
Conclusions: This report provides clinical and experimental results supporting the amyloidogenic nature of a novel TTR T60I variant. In vitro data indicate that the destabilising effect of individual T60I and V122I variants appears to be additive rather than synergistic.
期刊介绍:
Amyloid: the Journal of Protein Folding Disorders is dedicated to the study of all aspects of the protein groups and associated disorders that are classified as the amyloidoses as well as other disorders associated with abnormal protein folding. The journals major focus points are:
etiology,
pathogenesis,
histopathology,
chemical structure,
nature of fibrillogenesis;
whilst also publishing papers on the basic and chemical genetic aspects of many of these disorders.
Amyloid is recognised as one of the leading publications on amyloid protein classifications and the associated disorders, as well as clinical studies on all aspects of amyloid related neurodegenerative diseases and major clinical studies on inherited amyloidosis, especially those related to transthyretin. The Journal also publishes book reviews, meeting reports, editorials, thesis abstracts, review articles and symposia in the various areas listed above.