PT - JOURNAL ARTICLE AU - Eri Imagawa AU - Aviva Fattal-Valevski AU - Ori Eyal AU - Satoko Miyatake AU - Ann Saada AU - Mitsuko Nakashima AU - Yoshinori Tsurusaki AU - Hirotomo Saitsu AU - Noriko Miyake AU - Naomichi Matsumoto TI - Homozygous p.V116* mutation in <em>C12orf65</em> results in Leigh syndrome AID - 10.1136/jnnp-2014-310084 DP - 2016 Feb 01 TA - Journal of Neurology, Neurosurgery &amp; Psychiatry PG - 212--216 VI - 87 IP - 2 4099 - http://jnnp.bmj.com/content/87/2/212.short 4100 - http://jnnp.bmj.com/content/87/2/212.full SO - J Neurol Neurosurg Psychiatry2016 Feb 01; 87 AB - Background Leigh syndrome (LS) is an early-onset progressive neurodegenerative disorder associated with mitochondrial dysfunction. LS is characterised by elevated lactate and pyruvate and bilateral symmetric hyperintense lesions in the basal ganglia, thalamus, brainstem, cerebral white matter or spinal cord on T2-weighted MRI. LS is a genetically heterogeneous disease, and to date mutations in approximately 40 genes related to mitochondrial function have been linked to the disorder.Methods We investigated a pair of female monozygotic twins diagnosed with LS from consanguineous healthy parents of Indian origin. Their common clinical features included optic atrophy, ophthalmoplegia, spastic paraparesis and mild intellectual disability. High-blood lactate and high-intensity signal in the brainstem on T2-weighted MRI were consistent with a clinical diagnosis of LS. To identify the genetic cause of their condition, we performed whole exome sequencing.Results We identified a homozygous nonsense mutation in C12orf65 (NM_001143905; c.346delG, p.V116*) in the affected twins. Interestingly, the identical mutation was previously reported in an Indian family with Charcot-Marie Tooth disease type 6, which displayed some overlapping clinical features with the twins.Conclusions We demonstrate that the identical nonsense mutation in C12orf65 can result in different clinical features, suggesting the involvement of unknown modifiers.