However, homozygosity for the c.847delG (p.Asp283fs+54 aa) TIMMDC1 variant in a patient with Leigh syndrome was shown to have barely detectable TIMMDC1 protein, and thus lower levels of ATP content, mitochondrial respiratory activity and complex I in patient LCLs compared to control cells20. The gene discussed is TIMMDC1; the disease is Leigh syndrome.