Table 1.
Clinical, neuroradiological, biochemical and genetic features of five patients from three families with SDH-defective leukoencephalopathy and four unrelated patients with other, diverse phenotypes of complex II deficiency
| Patient (origin) | Sex | Present age | Affected/unaffected siblings | Consanguinity of parents | Age at onset | Presenting sign | MRI, proton MRS of the brain | Postmortem | Complex II activity measured in: (SDH residual activity normalized to CS) | SDHAF1mutation |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 (T) |
f |
Died at 18 mo |
1 (#2)/2 |
+ |
10 mo |
Motor regression |
Bilateral LE, succinate peak |
Leigh syndrome |
Muscle (46%), fibroblasts (24%) |
c.164 G > C a p.Arg55Pro |
| | ||||||||||
| 2 (T) |
f |
Died at 11 yrs |
1 (#1)/2 |
+ |
10 mo |
Motor regression |
Bilateral LE, succinate peak |
- |
Fibroblasts (74%) |
c.164 G > C a p.Arg55Pro |
| | ||||||||||
| 3 (N) |
m |
16 yrs |
-/2 |
Uncertain |
20 mo |
Spasticity, clumsiness |
Bilateral LE, succinate peak |
- |
Fibroblasts (16%) |
c.22C > T b p.Gln8X |
| | ||||||||||
| 4 (P) |
f |
Died at 5 yrs |
1 (#5)/1 |
+ |
14 mo |
Spasticity, motor regression |
Bilateral LE, succinate peak |
- |
Lymphocytes (39%) |
c.170 G > A b p.G57E |
| | ||||||||||
| 5 (P) |
f |
3 yrs |
1 (#4)/1 |
+ |
4 mo |
Spasticity |
Bilateral LE, succinate peak |
- |
Lymphocytes (58%) |
c.170 G > A b p.G57E |
| | ||||||||||
| 6 (G) |
m |
15 yrs |
-/- |
- |
3 yrs |
Exercise intolerance |
Normal, no succinate peak |
- |
Muscle (55%) |
None |
| 7 (J) |
f |
Died at 2 yrs |
-/- |
- |
18 mo |
Acute liver failure, liver transplantation |
- |
- |
Liver |
None |
| |
(42%) |
|||||||||
| 8 (J) |
f |
9 yrs |
-/2 |
- |
birth |
Psychomotor retardation, muscle weakness, hearing loss |
Normal |
- |
Muscle |
None |
| |
(45%) |
|||||||||
| 9 (J) |
f | 7 yrs | -/- | - | birth | Psychomotor retardation, muscle weakness, hypotonia | Normal | - | Muscle |
None |
| (71%) | ||||||||||
SDH succinate dehydrogenase; CS citrate synthase; (T) Turkish origin; (N) Norwegian origin; (P) Palestinian origin; (G) German origin; (J) Jewish origin; f female; m male; mo months; yrs years; + = present; - = absent/not done; LE = leukoencephalopathy; a mutation reported previously [2], b mutation not reported previously.