Investigation | No of participants (% of total) | Comments |
Blood investigations | ||
Clotting | 5 | Abnormal in one patient, but already known to be abnormal prior to referral for investigation of EDI |
Folate | 8 | Not diagnostic in any participant |
C reactive protein | 1 | Not diagnostic in any participant |
Erythrocyte sedimentation rate | 4 | Not diagnostic in any participant |
Glucose | 58 | No abnormalities |
Lactate | 178 | Persistently abnormal in one boy investigated at 1.4 years of age with dysmorphia, pulmonary stenosis, squint and hypertonia; MRS showed lactate peak although respiratory chain enzymes normal and no genetic diagnosis of mitochondrial disease made |
Acylcarnitine screen | 100 | Not diagnostic in any participant |
Magnesium | 3 | Not diagnostic in any participant |
Ammonia | 67 | Not diagnostic in any participant |
Homocysteine | 11 | Not diagnostic in any participant |
Uric acid | 103 | Not diagnostic in any participant |
Lipid/cholesterols | 40 | Not diagnostic in any participant |
White cell enzymes | 45 | Not diagnostic in any participant |
Very long chain fatty acids | 60 | Not diagnostic in any participant |
Transferrin isoelectric focusing | 46 | Not diagnostic in any participant |
Galactosaemia screen | 15 | Not diagnostic in any participant |
Copper | 21 | Not diagnostic in any participant |
Caeruloplasmin | 20 | Not diagnostic in any participant |
Free T3 | 9 | Not diagnostic in any participant |
Cortisol | 12 | Not diagnostic in any participant |
Vitamin A | 7 | Not diagnostic in any participant |
Vitamin B12 | 10 | Not diagnostic in any participant |
Vitamin D | 193 | Low levels were not felt to be the aetiological cause of EDI in any participant |
Vitamin E | 9 | Not diagnostic in any participant |
Coeliac screen | 40 | Not diagnostic in any participant |
Amylase | 5 | Not diagnostic in any participant |
Parathyroid hormone | 48 | Not diagnostic in any participant |
Immunoglobulins | 42 | Not diagnostic in any participant |
LDH | 3 | Not diagnostic in any participant |
Alpha fetoprotein | 5 | Not diagnostic in any participant |
ANA | 4 | Not diagnostic in any participant |
Rheumatoid factor | 2 | Not diagnostic in any participant |
Congenital infection screen | 34 | Not diagnostic in any participant |
Urine investigations | ||
Urine amino acids | 150 | Not diagnostic in any participant |
Urine creatinine | 13 | Not diagnostic in any participant |
Oligosaccharides | 12 | Not diagnostic in any participant |
Purine/pyrimidine studies | 30 | Often done after a marginally low uric acid, normal in all participants |
Cerebrospinal fluid tests | ||
CSF glucose lactate | 58 | Lactate raised in one boy investigated at 1.4 years of age with dysmorphia, pulmonary stenosis, squint and hypertonia; MRS showed lactate peak although respiratory chain enzymes normal and no genetic diagnosis of mitochondrial disease made Glucose low in two patients: a boy investigated at 1.7 years with EDI, hypotonia, seizures and paroxysmal upgaze when fasted; a girl investigated at 1.9 years with EDI, left hemiplegia and seizures. Both confirmed to have mutations in Glut 1 deficiency syndrome gene |
CSF amino acids | 19 | Diagnostic in two cases: a boy, investigated at 4 months of age for developmental impairment, poor visual function, evolving dystonia and microcephaly diagnosed with serine deficiency; a boy investigated at 0.8 year for developmental impairment, poor visual function and microcephaly whose plasma amino acids revealed low serine, ultimately diagnosed with serine deficiency |
CSF neurotransmitters | 32 | N`ot diagnostic in any participant |
CSF viral studies | 18 | Not diagnostic in any participant |
Other | ||
Skeletal survey | 2 | Not diagnostic in any participant |
Muscle biopsy | 9 | Not diagnostic in any participant |
Fibroblast culture | 2 | Sent for variety of tests—not diagnostic in any participant |
ANA, antinuclear antibody; CSF, cerebrospinal fluid; EDI, early developmental impairment; LDH, lactate dehydrogenase; MRS, magnetic resonance proton spectroscopy.