Eleven (22%) children with IBD were also eventually diagnosed via genetic testing with monogenic diseases, including chronic granulomatous disease (n = 6), familial Mediterranean fever (n = 1), Wiskott-Aldrich syndrome (n = 1), STAT-3 gain of function (n = 1), Hoyeraal Hreidarsson syndrome (n = 1), and activated PI3K-delta syndrome (n = 1). The gene discussed is STAT3; the disease is Hoyeraal-Hreidarsson syndrome.