What an NKH Family Says
Non-ketotic Hyperglycinemia is a condition where sufferers cannot make an enzyme that is used to metabolise, ie break down, glycine. It is a genetic condition and a genetic defect will have come from each parent. There are some cases where mutations cannot be found in one or both parents but this is very rare.
Glycine is an amino acid and is essential for our bodies to grow and develop.
By not being able to break down glycine and use it as we should, it causes two main problems.
Firstly development, movement, intelligence etc is severely affected as we need glycine for many things like cognitive function, learning and retaining information. As glycine is a neurotransmitter it is also vital in ensuring messages are transmitted correctly from the brain to other parts of the body.
Secondly, because glycine is not broken down and used, toxic levels of it build up in the blood, brain, spinal fluid, organs and tissues. This causes brain damage, seizures which can often be difficult to control, muscle weakness and/or spasticity and a variety of other serious medical issues.
There is no cure for NKH but there are treatments.
Sodium Benzoate (SB) is used to remove the excess glycine from the blood by, in effect, sticking to it, so it is passed out in urine. As SB only lowers levels in the blood, Dextromethorphan is used to dull the part of the brain that glycine aggravates when it is present in brain and spinal fluid. Most children will have at least one seizure medication and nearly all will take some sort of antacid or protein pump inhibitor to protect their stomach against the harsh effect of SB.
You will read many texts on NKH and what it does and all will be pretty depressing reading.
Sadly the mortality rate for children born with this condition is high and many die before they make it out of toddlerhood. Those that survive are often extremely disabled both mentally and physically with uncontrollable seizures. However, what you wont read is about mild cases, moderate cases and the successes and achievements of even the most severe cases. NKH is a devastating and often fatal condition but there are many many variations of it and these children consistently achieve more and live longer than we are led to believe.
A child with NKH has its own agenda and plan.
It wont have read the medical jargon on NKH and it will fight harder than you could ever imagine to simply be part of life. If you are a new parent to an NKH child, no matter what you are told, do not give up until the last. For every child that does exactly what the text books say they will, there is one that doesn’t.