An autosomal recessive primary immunodeficiency characterized by recurrent bacterial infections associated with agammaglobulinemia and absence of circulating B cells. Additional features include failure to thrive and skin involvement. The severity is variable: more severe cases may require hematopoietic stem cell transplantation, whereas others can be treated effectively with Ig replacement therapy. The disease is agammaglobulinemia 9, autosomal recessive (MONDO_0030519). Also known as: AGM9.