Asparagine synthetase deficiency is an autosoma
l recessive neurometabo
lic disorder characterized c
linica
lly by severe congenita
l microcepha
ly, g
loba
l deve
lopmenta
l de
lay, intractab
le epi
lepsy, and motor impairment in the form of spastic quadriparesis. Diagnosis is confirmed by findings of
low cerebra
l spina
l f
luid or p
lasma
asparagine in addition to a mutation of the subsequent
ly in
ASNS gene. There is no documented tria
l of
asparagine as a treatment for this disorder.
Patient Description
We present a child with asparagine synthetase deficiency whose mental status improved slightly from a vegetative state to a minimally conscious state after starting asparagine supplementation. He subsequently became irritable, developed sleep disturbance, and experienced worsening seizures, requiring discontinuation of the asparagine supplements.
Conclusions
Asparagine supplementation may be not effective in controlling the seizures in asparagine synthetase deficiency, and it is likely to make them worse.