Publication
Human germline biallelic complete NFAT1 deficiency causes the triad of progressive joint contractures, osteochondromas, and susceptibility to B cell malignancy
Publisher:
Cold Spring Harbor Laboratory
Date:
03-02-2022
DOI:
10.1101/2022.01.30.22269378
Abstract: Discovery of humans with monogenic disorders has a rich history of generating new insights into biology. Here we report the first human identified with complete deficiency of nuclear factor of activated T cells 1 (NFAT1). NFAT1, encoded by NFATC2 , mediates calcium-calcineurin signals that drive cell activation, proliferation, and survival. The patient is homozygous for a damaging germline NFATC2 variant (c.2023_2026delTACC p.Tyr675Thrfs*18) and presented with joint contractures, osteochondromas, and B cell lymphoma. Absence of NFAT1 protein in chondrocytes caused enrichment in pro-survival and inflammatory genes. Systematic single-cell-omic analyses revealed an environment that promotes lymphomagenesis with accumulation of naïve B cells (with oncogenic signatures - MYC , JAK1 ), exhausted CD4 + T cells, impaired T follicular helper cells, and aberrant CD8 + T cells. This work highlights the pleiotropic role of human NFAT1, will empower the diagnosis of additional patients with NFAT1 deficiency, and further define detrimental effects a long-term use of calcineurin inhibitors.