Affected Subject   S1   S2   S3   S4   S5   S06
Gender  female  female  male  male  male  female
Year of birth  1987  1998  1997  2000  2007  2009
Siblings (affected / unaffected / otherwise affected)  1 / 0 / 0  1 / 0 / 0  0 / 1 / 0  0 / 1 / 0  0 / 8 / 0  0 / 1 / 0
Consanguinity parents  −  −  +  +  +  −
Pregnancy, delivery, neonatal period  normal  normal  normal  normal  normal  normal
Initial motor & cognitive development  normal  normal  normal  normal  mildly delayed  normal
Single Episode of Regression
Age at presentation (years)  2.5  never developed neurological signs  3  5  5  2
Signs at presentation  L-hemiparesis, somnolence, irritability, loss of ambulation  NA  delayed speech, gait difficulties  gait difficulties  dysarthria and gait difficulties  frequent falls and leg weakness
Preceding event  recurrent vomiting and poor growth  NA  NA  NA  febrile illness  febrile illness
Signs of regression  severe spastic tetraparesis, lowered consciousness  NA  spastic tetraparesis L > R  spastic tetraparesis, ataxia and sensorimotor polyneuropathy with loss of unsupported walking  spastic tetraparesis, ataxia and sensorimotor polyneuropathy with loss of unsupported walking  spastic tetraparesis and sensorimotor polyneuropathy with loss of ambulation; gastrostomy due to swallowing defect
Treatment  temporary improvement on steroids; riboflavin, coenzyme Q10, thiamine and vitamin C  coenzyme Q10, carnitine and vitamin C  none  none  none  riboflavin, coenzyme Q10
Duration of regression  2 months  NA  2 years  2–3 months  2–3 months  5 months
Further regressions  seizures at age 4, controlled with carbamazepine; no further regression  NA  a somnolence episode with generalized seizure at age 5; 3 seizures during follow-up of 11 years; no further regression  no further regression  no further regression  no further regression
Outcome
Age (years)  26  14  16  13  6.5  4
Motor function  wheelchair-bound  normal  moderate spastic tetraparesis L > R; wheelchair-bound  walks, mild signs of spasticity, ataxia, and peripheral neuropathy  walks, mild signs of spasticity, ataxia, and peripheral neuropathy  walks, spastic gait
Cognitive level  decreased  normal  decreased  slightly decreased  normal  normal
Speech and language  single words, marked dysarthria  normal  dysarthria  normal  normal  normal