NDUFAF8-related pathology is associated with autosomal recessive inheritance. Diagnostic screening of NDUFAF8 is available as part of the NHS Genomic Medicine Service. Alston, Veling et al. describe pathogenic NDUFAF8 variants in three unrelated individuals including clear loss of function variants – 1 deep intronic splicing variant (reported in two unrelated individuals), 1 frameshift variant and 1 variant that is predicted to abolish the methionine initiation codon. 1 homozygous missense variant was also reported. Analysis of available patient cells showed a defect in complex I assembly that was rescued by expression of wild type NDUFAF8 cDNA.