Constitution of a cohort of IBMF patients, likely inherited, with unresolved origin after initial evaluation. *FA diagnosis was performed at initial evaluation, for all patients whose samples were sent in our laboratory, as we previously described, for example, MMC sensitivity in peripheral blood and skin fibroblast cells.^18,19  **Typical DBA, SDS, and other CN, and DC patients who were diagnosed up front with these syndromes based on a syndromic presentation were not included in the current “undiagnosed cases” WES study. Nevertheless, we subsequently identified additional patients with mutated DBA, SDS, or DC genes in our cohort through WES analysis. A posteriori, some of these patients had a presentation that might have been recognized as syndromic if fully evaluated. ***Physical abnormalities suggesting an inherited origin included skeletal abnormalities (thumb, jaw, or any limb malformation); neurological defects (developmental delay or intellectual disability, dyspraxia, attention deficit disorder, or abnormal MRI image); growth retardation; skin, nail, or hair abnormalities; genitourinary or renal malformations (renal agenesis, cryptorchidic testis); cardiac abnormalities (valvular heart disease, heart failure); lung abnormalities (mainly restrictive syndrome or fibrosis), liver abnormalities (cirrhosis, fibrosis). BMF, bone marrow failure; MMC, mitomycin C; WES, whole-exome sequencing.