Table 1 Clinical features of cases with asparagine synthetase deficiency due to ASNS gene mutation
From: Hyperekplexia, microcephaly and simplified gyral pattern caused by novel ASNS mutations, case report
Present report | Ruzzo et al. [1] | Ben Salem et al. [3] | Alfadhel et al. [2] | ||
|---|---|---|---|---|---|
Patient 1 | Patient 2 | ||||
Number of pts | 2 | 9 | 1 | 2 | |
Number of families | 2 | 4 | 1 | 1 | |
Age | 1 month | 4 Yrs | 9 month–14 Yrs | 5 Yrs | 2 Yrs/4 Yrs |
Gender | M | M | 8M/1F | M | 1M/1F |
Ethnic origin | Arab | Arab | Iranian Jews, French | Arab | Arab |
Canadian, Bangladeshi | |||||
Consanguinity | Yes | Yes | Yes in two families | Yes | Yes |
Mutation in ASNS gene | c.1219C > T | c.944A > G | c. 1084T > G(p.Phe 362Val | c. 1193 A > C p.Y 398 C | c. 1160A > G |
p.(Arg407) | p.Y 315 C | c. 1648C > T(p.Arg 550Cys | p. Tyr 377Cys | ||
c 17C > A(p. A6E | |||||
Type of mutation | Nonsense homozygous | Missense, homozygous | Missense, homozygous, compound heterozygous | Missense, homozygous | Missense, homozygous |
Developmental delay | Severe | Severe | Severe | Severe | |
Head circumference (cm )at birth | 29 | 29 | 28.5–33 | 29.5 | 30 and 26.5 |
Hypertonia | No | Yes | Yes | Yes | Yes |
Spastic quadriplegia | No | Yes | Yes | Yes | Yes |
Seizure | Yes | No | 6 patients | Yes | Yes, both |
Hyperekplexia | Yes | Yes | Three patients | No | No |
EEG Pattern | Epileptic encephalopathy in a transitional phase with predominant SZ burdens | Low amplitude bilaterally but no clear epileptiform discharge | • Disorganized background In hyperekplexia cases • Hypsarrhythmia • Suppression burst | Abnormal background activity bilaterally, low amplitude and frequent interictal multifocal spike | Multiple independent spike foci |
MRI Brain | Microcephaly, smooth thin cerebral cortex, simplified gyral pattern, global brain atrophy, delayed myelination, hypoplastic cerebellum and pons | Microcephaly, smooth thin cerebral cortex, simplified gyral pattern, global brain atrophy, delayed myelination, hypoplastic cerebellum and pons | All have severe microcephaly, brain atrophy delayed myelination, decreased size of the pons and simplified gyral pattern | Severe microcephaly thin corpus callosum, ventriculomegaly, brain atrophy, decreased size of pons, simplified gyral pattern | Both severe microcephaly brain atrophy, delayed myelination and simplified gyral pattern |