ClinVar

This variant is classified as a variant of unknown significance because its contribution to lethal infantile mitochondrial myopathy (LIMM; 551000) has not been confirmed.

Yoon et al. (1991) described 2 patients with severe respiratory chain enzyme deficiency and associated lactic acidosis who died within days after birth. They detected an A-to-G mutation at nucleotide pair (np) 15924 in one patient and an A-to-G mutation at nucleotide pair 15923 in the other. Both mutations occurred within the tRNA anticodon stem-loop structure. Brown et al. (1992) screened 3 LIMM and multiple control subjects for these mutations and reported that the nucleotide pair 15924 A-to-G mutation found in one of the patients was not the primary cause of LIMM because the mutation was detected in the proband's unaffected mother. Furthermore, Brown et al. (1992) found the nucleotide pair 15924 mutation in approximately 11% (11/103) of Caucasian controls. The nucleotide pair 15923 mutation was not detected in 91 Caucasians, 35 Africans, and 57 Asians.