An extremely rare genetic disorder that causes a build up of ammonia in the blood can now be tackled with a new drug approved by the US Food and Drug Administration (FDA).
The disease, N-acetylglutamate synthase or Nags deficiency, is present in babies soon after they are born and may be fatal if left untreated.
However, carglumic acid or Carbaglu tablets are now available, following lab tests revealing ammonia levels in subjects normalised within three days.
Dr Janet Woodcock, director of the FDA's centre for drug evaluation and research, said she and her organisation were hoping for similar progress in other medications.
"We are very excited that more drugs are being developed to treat very rare but often devastating genetic disorders," she added.
The FDA recently accepted the use of botox for treating upper-limb spasticity, with injections found to ease muscle tremors in those who have suffered strokes, brain damage or have multiple sclerosis.