Table 4:

Distribution of abnormal values in different patient groups, by biomarker^*

	FGF-21 (pg/mL)		Lactate (mmol/L)		Pyruvate (μmol/L)		Lactate:pyruvate†		Creatine kinase (U/L)‡
	<200	>200	<2.4	>2.4	<70	>70	<30	>30	Normal	Raised
Adult muscle-manifesting mitochondrial disorders (MELAS, PEO, and MNGIE; n=29)	3	26	15	10	4	7	10	1	15	7
Adult mitochondrial disorders with nervous system involvement (MIRAS; n=12)	7	5	10	1	2	7	9	0	11	1
Child muscle-manifesting mitochondrial disorders (n=23)	1	22	2	19	2	10	3	9	3	7
Non-mitochondrial neurological disorders (adults [n=22]/children [n=15])	17/11	5/1	8/6	0/3	0/1	0/0	0/1	0/0	5/1	17/1
Controls	71	3	50	2	40	6	46	0	50	2

MELAS=mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes. PEO=progressive external ophthalmoplegia. MNGIE=mitochondrial neurogastrointestinal encephalomyopathy. MIRAS=mitochondrial recessive ataxia syndrome.

^*Numbers vary across biomarkers because all data were not available for all patients.

^†Calculated as 1000×(lactate)/(pyruvate).

^‡Reference values for age-groups are described on webappendix p 5.