Human complete NFAT1 deficiency causes a triad of joint contractures, osteochondromas, and B-cell malignancy
Mehul Sharma, Maggie P. Fu, Henry Y. Lu, Ashish Sharma, Bhavi P. Modi, Christina Michalski, Susan Lin, Joshua Dalmann, Areesha Salman, Kate L. Del Bel, Meriam A. Waqas, Jefferson Terry, Audi Setiadi, Pascal M. Lavoie, Wyeth W. Wasserman, Jill Mwenifumbo, Michael S. Kobor, Anna F. Lee, Florian Kuchenbauer, Anna Lehman, Sylvia Cheng, Anthony Cooper, Millan S. Patel, Stuart E. Turvey
Abstract
The 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 recurrent B-cell lymphoma. Absence of NFAT1 protein in chondrocytes caused enrichment in prosurvival and inflammatory genes. Systematic single-cell-omic analyses in PBMCs revealed an environment that promotes lymphomagenesis with accumulation of naïve B cells (enriched for oncogenic signatures MYC and 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 defines the detrimental effects associated with long-term use of calcineurin inhibitors.