Cindy Yee Kong mysterious disabling disease is Dopa-responsive dystonia ,also known as Tyrosine Hydroxylase deficiency is an autosomal recessive disorder resulting from cerebral catecholamine deficiency. Tyrosine hydroxylase helps convert the protein building block (amino acid) tyrosine to L-dopa to a catecholamine called dopamine.

Dopamine transmits signals to help the brain control physical movement and emotional behavior and learning. It helps control the  brain's reward and pleasure centers and enables us not only to see rewards, but to take action to move toward them. Dopamine helps in focus, attention, memory and flow of information from others area of the brain. Dopamine is a precursor for three important neurotransmitters: norepinephrine, epinephrine and serotonin. The treatment for dopa-responsive dystonia is L-dopa.

Resources

http://en.wikipedia.org/wiki/Dopamine 

https://www.psychologytoday.com/basics/dopamine

https://en.wikipedia.org/wiki/Norepinephrine 

https://en.wikipedia.org/wiki/Epinephrine 

https://en.wikipedia.org/wiki/Tyrosine_hydroxylase 

http://www.news-medical.net/health/What-is-Epinephrine-(Adrenaline).aspx 

http://www.ncapd.org/What_is_APD_.html 

http://ghr.nlm.nih.gov/condition/tyrosine-hydroxylase-deficiency 

http://www.scilearn.com/blog/dopamine-learning-brains-reward-center-teach-educators 

http://www.addictscience.com/dopamine-learning/ 

http://en.wikipedia.org/wiki/L-DOPA 

http://en.wikipedia.org/wiki/Catecholamine 

http://www.news-medical.net/health/Dopamine-Functions.aspx 

http://www.neurogistics.com/thescience/whatareneurotransmi09ce.asp 

http://en.wikipedia.org/wiki/Dopamine-responsive_dystonia 

http://ghr.nlm.nih.gov/condition/dopa-responsive-dystonia