Table 2.
Demographic, clinical and electroencephalographic features observed in the present series with PNPO deficiency
| Clinical features and demographics | Incidence |
|---|---|
| Gender | Male n = 9; female n = 6 |
| Ethnicity | Caucasian n = 10; Turkish n = 1; Asian (British) n = 1; Kosovan n = 1; Pakastani n = 1; Unknown n = 1 |
| Parental consanguinity | 3/11 (27%) |
| Family history of infertility / foetal loss | 4/12 (25%) |
| Gestational age ≤ 37/40 | 6/13 (46%) |
| Abnormal intrauterine movements | 3/11 (27%) |
| Foetal distress | 4/11 (36%) |
| Apgar score <7 at 1 min | 2/11 (18%) |
| Acidosis | 5/10 (50%) |
| Respiratory distress | 4/11 (36%) |
| Hypotonia (neonatal) | 6/10 (60%) |
| Abdominal distension / vomiting | 1/7 (14%) |
| Irritability | 4/10 (40%) |
| Seizure onset within first 28 days | 12/14 (86%) |
| Resistance to antiepileptic drugs | Complete: 8/14 (57%); partial: 6/14 (43%) |
| EEG | Burst suppression: 6/11 (55%); Hypsarrhythmia: 1/11 (9%); Otherc: 4/11 (36%) |
| Seizure type: clonic | 5/11 (45%) |
| Seizure type: tonic | 3/10 (30%) |
| Seizure type: generalized tonic-clonic | 11/14 (79%) |
| Seizure type: myoclonic jerks | 6/11 (55%) |
| Seizure type: focal | 5/11 (45%) |
| Response to pyridoxine | 8/13 (62%) |
| Worsening of seizures upon change from PN to PLP | 3/8 (38%) |
| Trial of PLPa | 10/15 (67%) |
| Response to PLP trial | Immediate: 6/10 (60%); within 12 h to 3 days: 2/10 (20%) |
| Trial of PLP withdrawalb | 5/7 (71%) |
| Speech delay | 8/13 (62%) |
| Motor delay | Marked: 3/12 (33%); Minimal: 3/12 (17%); None: 6/12 (50)% |
| Breakthrough seizures with fever | 6/12 (50%) |
| Observed in the present series but not previously described in clinically diagnosed PNPO deficiency | |
| Severe neuropathy with persistent loss of ankle jerks (75 mg TDS PN) | 1 patient |
| Gut perforation and septicaemia | 1 patient |
| Liver function abnormalities | 2 patients |
aOne patient treated prophylactically.
bEither planned, accidental or reduced dose/kg due to age.
cIncluded suppression rhythms over right mid-temporal zone and focal seizures (bilateral, independent) for one patient and generalized suppressions and sharp wave complexes over both hemispheres for another. Where the incidence denominator is <15 the information was not completed/available for the patient in the proforma returned by the treating clinician.