Table 1.

Main Clinical and Genetic Characteristics of Patients With TK2 Deficiency

ID	Age at onset	Ambulant	Age at Mv onset	Muscle biopsy	Muscle mtDNA levels	Multiple deletions	Genetics (allele 1)	Genetics (allele 2)	Ns	Exitus (age)
1	<12 mo	—	—	1	9%	ND	p.Arg130Trp	p.Ile168ThrfsTer2	0	1
2	<12 mo	—	—	1	ND	ND	p.Thr108Met	p.Leu233Pro	0	1 (4 y)
3	<12 mo	—	—	1	ND	ND	p.Arg254Ter	p.Arg254Ter	0	1
4	<12 mo	1	0	1	18%	1	p.Thr108Met	p.Thr108Met	1	0
5	12–36 mo	1	0	1	42%	1	p.Thr108Met	p.Arg192Lys	0	—
6	12–36 mo	—	27 y	1	ND	1	p.Tyr208Cys	p.Tyr208Cys	0	1
7	12–36 mo	0	17 mo	1	17%	0	p.His121Asn	p.Arg192Lys	1	0
8	12–36 mo	0	29 mo	1	15%	0	p.Tyr208Cys	p.Arg130Trp	1	0
9	12–36 mo	1	0	1	17%	0	p.Thr108Met	p.Arg192Lys	1	0
10	12–36 mo	1	0	1	25%	0	p.Asp177Tyr	p.Lys202del	1	0
11	12–36 mo	0	21 y	1	45%	1	p.Thr108Met	p.Thr108Met	1	0
12	12–36 mo	1	0	0	ND	ND	p.Thr108Met	p.Thr108Met	1	0
13	12–36 mo	1	0	0	ND	ND	p.Lys202del	p.Gln125Ter	1	0
14	12–36 mo	0	6 y	1	ND	ND	p.Lys202del	p.Ser51Ilefs*99	0	1 (8 y)
15	12–36 mo	1	0	1	8%	0	p.Thr108Met	p.Thr108Met	1	0
16	3–12 y	1	0	1	ND	ND	p.Thr108Met	p.Pro227Serfs*9	1	0
17	3–12 y	0	14 y	1	<10%	1	p.Arg183Gly	p.Lys202del	1	0
18	3–12 y	1	0	1	57%	1	p.Thr108Met	p.Thr108Met	0	—
19	3–12 y	1	35 y	1	29%	1	p.Thr108Met	p.Thr108Met	1	0
20	3–12 y	—	0	1	ND	ND	p.Lys202del	p.Lys202del	0	1 (29 y)
21	3–12 y	1	42 y	1	48%	1	p.Tyr208Cys	p.Lys202del	0	0
22	12–40 y	0	38 y	1	ND	1	p.Thr108Met	p.Thr108Met	0	1 (49 y)
23	12–40 y	1	56 y	1	ND	1	p.Thr108Met	p.Thr108Met	1	0
24	12–40 y	1	32 y	1	17%	1	p.Thr108Met	p.Thr108Met	1	0
25	12–40 y	1	0	1	48%	1	p.Thr108Met	p.Thr108Met	0	0
26	12–40 y	1	0	1	ND	1	p.Tyr208Cys	p.Tyr208Cys	1	0
27	12–40 y	1	0	1	ND	1	p.Lys202del	p.Lys202del	0	0
28	12–40 y	1	38 y	1	ND	1	p.Thr108Met	p.Thr108Met	0	0
29	12–40 y	1	28 y	1	39%	1	p.Thr108Met	p.Thr108Met	1	1 (28 y)
30	12–40 y	—	40 y	1	ND	1	p.Ser51Ilefs*99	p.Ala139Thr	0	0
31	12–40 y	—	—	1	ND	ND	p.Lys202del	p.Lys202del	0	1
32	12–40 y	1	30 y	1	ND	ND	p.Thr108Met	p.Thr108Met	0	1 (40 y)
33	12–40 y	1	0	1	ND	ND	p.Tyr208Cys	p.Tyr208Cys	1	0
34	12–40 y	—	—	1	ND	ND	p.Lys202del	p.Lys202del	0	1 (42 y)
35	12–40 y	1	45 y	1	ND	1	p.Thr108Met	p.Thr108Met	1	0
36	12–40 y	1	0	1	53%	1	p.Lys202del	p.Lys202del	0	0
37	12–40 y	1	61 y	1	ND	ND	p.Lys202del	p.Lys202del	0	0
38	12–40 y	1	0	1	ND	1	p.Lys202del	p.Lys202del	0	1
39	12–40 y	1	61 y	1	60%	1	p.Lys202del	p.Lys202del	1	0

Abbreviations: ID = identification number; MV = mechanical ventilation; ND = not done; UNK = unknown; 0 = No; 1 = yes; — = data not available. Patients with onset of symptoms before 1 year of age, between 1 and 3 years of age, between 3 and 12 years of age, and 12 and 40 years of age.