The influence of haplotypes and single nucleotide polymorphisms (SNPs) of mitochondrial DNA (mtDNA) on the penetrance of the primary Leber's hereditary optic neuropathy (LHON) mutation m.11778G>A in MT-ND4 in 47 unrelated Polish male patients. The authors suggest that haplogroup K and several mtDNA SNPs could determine the penetrance of this variant in the cohort. However, the conclusions are deemed speculative due to the small sample size and inconclusive distribution of SNPs between patients and controls. The authors' statement that LHON symptoms are limited to a single organ is challenged, as LHON is considered a multisystem disease. The claim that LHON is the most common mitochondrial disorder is also disputed, with non-syndromic mitochondrial disorders being more prevalent. Additionally, the primary site of affection in LHON is argued to be the retina, not the optic nerve. The study's limitations include the unclear clinical status of patients and lack of information on idebenone treatment. Further research is suggested to investigate the influence of nuclear DNA genes on the penetrance of mtDNA variants.