Smith-Magenis syndrome (SMS) is a sporadic congenital disorder involving multiple organ systems caused by chromosome 17p11.2 deletions. Smith-Magenis syndrome features craniofacial and skeletal anomalies, cognitive impairment, and neurobehavioral abnormalities. In addition, some SMS patients may exhibit hypogammaglobulinemia. We report the first case of SMS-associated autoimmunity in a woman who presented with adult onset of multiple autoimmune disorders, including systemic lupus erythematosus, antiphospholipid antibody syndrome, and autoimmune hepatitis. Molecular analysis using single-nucleotide polymorphism array confirmed a de novo 3.8-Mb deletion (breakpoints, chr17: 16,660,721-20,417,975), resulting in haploinsufficiency for TACI (transmembrane activator and CAML interactor). Our data are consistent with potential loss of function for the BAFF (B cell–activating factor) receptor TACI as a contributing factor to human autoimmune phenomena.
From the*Division of Rheumatology, Department of Medicine, University of Minnesota, Minneapolis, MN; and †Cancer Genetics Branch, ‡Medical Genetics Branch, and §Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD.
This research was supported in part by the Intramural Research Program of the National Human Genome Research Institute, National Institutes of Health, Bethesda, MD.
The authors declare no conflict of interest.
Correspondence: Erik J. Peterson, MD, Division of Rheumatology, Department of Medicine and Center for Immunology, 2-112 MBB, 2101 6th St SE, University of Minnesota, Minneapolis, MN 55455. E-mail: firstname.lastname@example.org.