Patients with complex I or I/III: clinical and biochemical features
| Patient | Age (yr) | ETC Activity | Abnormal Labs | Clinical | MRI Findings | |
|---|---|---|---|---|---|---|
| Complex I | Citrate Synthase | |||||
| 1 | 13 | 15% | 96% | None | DD, S, GI-C, H, M, ADHD | Normal |
| 2 | 13 | 16.7% | 111% | UOA | DD, S, FTT, Micro, A, GI-C | Micro |
| 3 | 7 | 25% | 100% | UOA, Lac | DD, M, GI-C, H | Normal |
| 4 | 3 | 11.7% | 140% | UOA | DD, H, M, GI-C | Normal |
| 5 | 1 | 4% | 94% | CSF | DD, S, FTT, GI-C, M, H | Mild cerebral volume loss |
| 6 | 8 | 5% | <5%a | None | HA, M, OP | Normal |
| 7 | 13 | 0% | 100% | None | DD, M, GI, H, OP | Normal |
| 8 | 4 | 8% | 130% | UOA, Lac-B | H, DD, S, GI, M | Normal |
| 9 | 2 | 15% | 179% | UOA | DD, M, GI-C, GI, H | Normal |
| 10 | 5 | 0% | 84% | None | DD, FTT, GI, M | Mild cerebral and cerebellar volume loss |
Note:—ETC indicates electron chain transfer; UOA, urine organic acids; Lac, lactic academia; Lac-B, lactate peak on MRS; CSF, elevated cerebral spinal fluid protein; OP, ophthalmologic abnormality; DD, developmental delay; S, seizures; FTT, failure to thrive; M, muscle weakness/endurance problems; GI, gastrointestinal dysmotility; GI-C, severe constipation; H, hypotonia; Micro, microcephaly; A, autism spectrum disorder; ADHD, attention deficit/hyperactivity disorder; HA = migraine headache.
↵a Complex II was 100% in this patient.