Table 1.

Biochemical and Clinical Findings in Individuals with TRMT10C Variants

ID	Sex	TRMT10C Variants	OXPHOS Activities in Skeletal Muscle					Clinical Features
		cDNA (NM_017819.3); Protein (NP_060289.2)	RCC	% Mean Enzyme Activity	Absolute Values	Control Mean (Reference Range)	Muscle Biopsy Findings	Age at Onset	Clinical Course	Other Clinical Features and Relevant Family History
Subject 1a	male	c.[542G>T];[814A>G]; p.[Arg181Leu];[Thr272Ala]	I II III IV	48% (↓) 103% 98% 23% (↓)	0.050 0.150 0.543 0.259	0.104 ± 0.036 (n = 25) 0.145 ± 0.047 (n = 25) 0.554 ± 0.345 (n = 25) 1.124 ± 0.511 (n = 25)	COX-deficient, ragged-red fibers	birth	died at 5.5 months	myopathy, hypotonia, sensorineural deafness, liver involvement; elevated serum and CSF lactate levels
Subject 2b	female	c.[542G>T];[542G>T]; p.[Arg181Leu];[Arg181Leu]	I II III IV CS	64% (↓) 293% 8% (↓) 6% (↓) 332%	11 88 24 9 319	17 ± 4 (n = 50) 30 ± 7 (n = 50) 303 ± 57 (n = 50) 144 ± 34 (n = 50) 96 ± 18 (n = 50)	ND	birth	died at 5 months	hypotonia, deafness; elevated serum, urine, and CSF lactate levels

^aRespiratory chain complex (RCC) activities are expressed as nmols NADH oxidised.min⁻¹.unit citrate synthase⁻¹for complex I, nmols DCPIP reduced.min⁻¹.unit citrate synthase⁻¹ for complex II and K.s⁻¹.unit citrate synthase⁻¹ × 10³ for complexes III and IV

^bRespiratory chain complex (RCC) activities are expressed as nmol/min/mg protein