Table 1.
Clinical characteristics of Chinese mainland type I sialidosis patients in our study.
| Patient 1, this study | Patient 2, this study | Patient 3, this study | Patient 4, this study | Patient 5, this study | |
|---|---|---|---|---|---|
| Age/gender | 17/M | 14/F | 31/M | 20/F | 19/M |
| Past history | Easily tired after exercise; bad sports performance | Bad sports performance | Unremarkable | Bad sports performance | Unremarkable |
| Family history | Unremarkable | Unremarkable | Unremarkable | Unremarkable | Unremarkable |
| Symptom onset age | 12 years old | 12 years old | 17 years old | 10 years old | 10 years old |
| Initial symptoms | GTCS | Symmetric distal neuropathic pain | Myoclonus | A and falls | GTCS |
| Seizures | GTCS; MCS | GTCS; MCS | GTCS; MCS | GTCS; MCS | GTCS; MCS |
| Other symptoms | D; falls; A; hyperreflexia | CI; D; falls; A; bedridden; hyperreflexia | D; falls; A; hypertonia; hyperreflexia | D; bedridden | D; A; nystagmus; unequal pupils; hyperreflexia; ankle clonus |
| Visual acuity | Gradually declined | Gradually declined | Gradually declined | Gradually declined | Gradually declined |
| Aural acuity | Gradually declined; bilateral nervous deafness | Normal | Normal | Normal | Normal |
| Brain MRI | Normal | Widening of bilateral cerebellar sulcus | Normal | Normal | Mild atrophy of cerebellar vermis and enlargement of midbrain aqueduct |
| EMG | Bilateral F‐waves were not elicited | Normal | Normal | U | Neurogenic damage of extremities |
| BAEP | Normal | Normal | Normal | U | Abnormal waveform differentiation |
| VEP (P100) | Abnormal peak latency and amplitude | Abnormal peak latency and amplitude | Normal | U | Prolonged peak latency |
| SEP of upper limb | Huge potential | Huge potential | Huge potential | U | Huge potential |
| SEP of lower limb | Abnormal deep sensory conduction | Abnormal deep sensory conduction | Abnormal deep sensory conduction | U | Abnormal deep sensory conduction |
| Ocular fundus | CRS | Punctate opacity of binocular lens; CRS | CRS | Punctate opacity of binocular lens; CRS | CRS |
| Visual field | Diffuse defect of OU visual field | OS, defect except the lower quadrant of nasal field; OD, enlargement of physiological blind spot | Normal | Normal | Normal |
| OCT | Diffuse weakness of bilateral RNFL and GCC; hyperreflex of macular inner layer | Basically normal | Hyperreflex of macular inner layer | U | Hyperreflex of macular inner layer |
| Blood examination | Normal | Normal | Normal | Normal | Normal |
| CSF examination | Normal | Weakly positive of oligoclonal band | Normal | Normal | Normal |
| Mutation of NEU1 | c.803A > G; c.239C > T | c.544A > G; c.239C > T | c.544A > G; c.239C > T | c.838G > A; c.403C > T | c.1118T > C; c.544A > G |
| Transmission | Hereditary mutation | Hereditary mutation | Hereditary mutation | Hereditary mutation | U |
| Therapy | LEV, 750 mg/bid; VPA, 500 mg/bid; CZP, 0.5 mg/bid | LEV, 500 mg/bid to 750 mg/bid; CZP, 1 mg/tid | LEV, 500 mg/bid; CZP, 1 mg/qn | LEV, 500 mg/bid | U |
| Outcome | 2 m later: GTCS, zero; MCS and A, obviously improved | 6 m later: loss of self‐sufficiency; 2 y later: GTCS, 1–3/m; MCS, daily; A and visual function deteriorated even further | 2 y later: seizures, A and visual function deteriorated even further | Seizures and A improved | U |
F, female; M, male; U, unsure; GTCS, generalized tonic–clonic seizure; A, ataxia; MCS, myoclonus seizures; CI, cognitive impairment; D, dysarthria; MRI, magnetic resonance imaging; EMG, electromyography; BAEP, brainstem auditory evoked potential; VEP, visual evoked potential; SEP, somatosensory evoked potential; CRS, cherry red spot; OD, oculus dexter; OS, oculus sinister; OU, oculus unati; OCT, optical coherence tomography; RNFL, retina nerve fiber layer; GCC, ganglion cell complex; CSF, cerebrospinal fluid; LEV, levetiracetam; CZP, carbamazepine; VPA, valproic acid.