CTLA4 Alteration and Neurologic Manifestations: A New Family with Large Phenotypic Variability and Literature Review.

Abstract

Cytotoxic-T-lymphocyte-antigen-4 (CTLA-4), a member of the immunoglobulin superfamily, is an essential negative regulator of immune responses that is constitutively expressed on both regulatory (Treg) and activated T cells. To date, heterozygous germline variants in CTLA4, leading to haploinsufficiency, have been associated with several immunological disorders, including hypogammaglobulinemia, multi-organ autoimmunity, lymphoproliferative disorders, and enlarged lymphoid organs. Indeed, CTLA4 carriers display highly heterogeneous clinical manifestations with a phenotypic spectrum ranging from asymptomatic carrier status to fatal autoimmunity. Here, we describe a family with autoimmune phenotypes (Hashimoto thyroiditis, psoriasiform dermatitis, celiac disease/inflammatory bowel disease, and rheumatoid arthritis), segregating across three different generations due to a recurrent missense variant [c.436G>A, p.(Gly146Arg)] in the CTLA4 gene. Interestingly, the proband showed prominent neurological manifestations, including seizures, hydrocephalus, and demyelination, which are less frequently reported in individuals with pathogenic variants in CTLA4. A detailed literature review of neurologic features that have been reported so far in CTLA4 carriers is also provided.