RMRP and immune system disorder: Nine patients were categorized as having other syndromic immunodeficiencies, in particular: hepatic veno-occlusive disease with immunodeficiency (n = 2 with SP110 mutations), STAT5B deficiency (n = 2), MYSM1 deficiency (n = 2) cartilage hair hypoplasia (n = 1 with RMRP mutation), TTC7A deficiency (n = 1), and HOIP deficiency (n = 1 with RNF31 mutation).