Characteristics of each disease type in 281 newborns with neonatal-onset mitochondrial disease
| Characteristic | N | |||
| MsMD (n=194), n (%) | LS (n=26), n (%) | CM (n=38), n (%) | HD (n=23), n (%) | |
| Male | 91 (47) | 18 (69) | 17 (45) | 12 (52) |
| Female | 103 (53) | 8 (31) | 21 (55) | 11 (48) |
| Preterm delivery* | 64/175 (37) | 4/21 (19) | 12/29 (41) | 7/20 (35) |
| SGA* | 64/168 (38) | 6/20 (30) | 7/28 (25) | 6/19 (32) |
| Alive† | 108 (56) | 20 (77) | 15 (39) | 12 (52) |
| Deceased (≤28 days after birth)† | 51 (26) | 0 | 9 (24) | 6 (26) |
| Deceased (>28 days after birth)† | 35 (18) | 6 (23) | 14 (37) | 5 (22) |
| Onset (0–1 day after birth)† | 163 (84) | 17 (65) | 33 (87) | 13 (57) |
| Onset (2–28 days after birth)† | 31 (16) | 9 (35) | 5 (13) | 10 (43) |
| Hyperlactataemia (>2.1 mM)*† | 132/146 (90) | 16/20 (80) | 14/20 (70) | 13/17 (76) |
| Diagnosed by biochemical approach | 189 (97) | 24 (92) | 36 (95) | 22 (96) |
| Diagnosed by MRC enzyme activity | 122 (63) | 13 (50) | 26 (69) | 20 (87) |
| C I | 57 (30) | 4 (15) | 10 (27) | 8 (35) |
| C II | 0 | 0 | 0 | 1 (4) |
| C III | 4 (2) | 0 | 2 (5) | 0 |
| C IV | 16 (8) | 4 (15) | 1 (3) | 1 (4) |
| Combined | 45 (23) | 5 (20) | 13 (34) | 10 (43) |
| Diagnosed by OCR‡ | 67 (34) | 11 (42) | 10 (26) | 2 (9) |
| Diagnosed by genetic approach | 5 (3) | 2 (8) | 2 (5) | 1 (4) |
*Number of patients with available information only.
†There is a significant difference in the multiple comparisons with Fisher’s exact tests using the Bonferroni method among four disease types.
‡No decrease in MRC enzyme activity.
C I, complex I; C II, complex II; C III, complex III; C IV, complex IV; CM, cardiomyopathy; HD, hepatic disease; LS, Leigh syndrome; MRC, mitochondrial respiratory chain; MsMD, multisystem mitochondrial disease; OCR, oxygen consumption rate; SGA, small-for-gestational-age.