%C England %L discovery10065788 %V 12 %K connective tissue disease, immunology %N 1 %J BMJ Case Reports %X Selective immunoglobulin M deficiency (sIgMD) is an immunodeficiency with undefined pathogenesis and commonly presenting with recurrent infections. 1 The European Society for Immunodeficiencies Registry defines sIgMD as a serum IgM level repeatedly below 2 SD of normal with normal levels of serum IgA, IgG and IgG subclasses, normal vaccination responses, absence of T-cell defects and absence of causative external factors. Rarely it can also be associated with autoimmune diseases. 2-7 Here we describe a patient with primary sIgMD; who presented with multiple autoimmune diseases without a history of recurrent infections and we provide a short literature review on sIgMD and autoimmune diseases. %A C Campochiaro %A S Atay %A KEN Clark %A V Ong %A CP Denton %T Autoimmunity and immunodeficiency at the crossroad: autoimmune disorders as the presenting feature of selective IgM deficiency %O This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. %D 2019