We have previously shown that SIFD patient-derived fibroblasts exhibit reduced basal and maximal respirations rates due to decreased expression of key core ETC proteins (NDUFB8, SDHB, COXII) (13), likely resulting from defective TRNT1-mediated mitochondrial translation (7). Here, SDHB is linked to congenital sideroblastic anemia-B-cell immunodeficiency-periodic fever-developmental delay syndrome.