What is Type 2 Gaucher disease?
Type 2 Gaucher disease is a very rare, rapildly progessive form of Gaucher disease which affects the brain (central nervous system) as well as the spleen, liver, lungs and bones. Formerly called infantile Gaucher disease, it is characterised by severe neurological (brain) involvement in the first year of life. It is also called acute neuronopathic Gaucher disease. Fewer than 1 in 100,000 newborn babies have Type 2 disease and this form of the disease shows no ethnic predilection.
Babies usually appear normal at birth but develop symptoms by the age of 3 to 6 months. Type 2 is almost always apparent by 6 months of age. The vast majority of children die by the age of two years. However, a small number have survived a little longer.
Signs and symptoms include failure to thrive, rigidity of the neck and limbs (hypertonia), head thrust back, lockjaw (trismus), squinting (strabismus) and difficultly in swallowing. Other difficulties include vocal cord (laryngeal) spasm, seizures and a failure to shake off chest infections. The spleen and liver often become very enlarged with accompanying low blood counts. The baby may eventually become increasingly unresponsive for a period before death.
Much of what is known about Type 1 and 3 Gaucher disease is equally true of Type 2. The nzyme deficiency, how the waste materal is stored in the body, and the mode of inheritance are all identical.
No specific treatment for Type 2 Gaucher disease is available. Enzyme replacement therapy which is used to treat patients with Type 1 and 3 Gaucher disease is ineffective in Type 2.
With help and support, parents can deal with many unfamiliar situations. Doctors may outline, at the time of diagnosis, how the disease will progress but it may be difficult at that moment for parents to fully anticipate the practical difficulties which may arise.
There are certain specific problems that may need symptomatic treatment which are not caused by brainstem involvement:
1. Swallowing - is affected very early in the course of the disease. The earliest symptoms are choking or refusal of food. Later, the inability to keep the airway clear during the act of swallowing means that food may go down into the windpipe. (trachea) and lungs. This is known as aspiration and may result in repeated chest infections. Frequent assessments should be carried out to ensure that the swallowing is safe. If necessary a dysphagia (swallowing difficulties) speech and language therapist should assess this although it is usually fairly obvious when there is a problem. If swallowing becomes difficult, then an alternative method of feeding needs to be considered. Initially nasogastric (a tube passed through the nose into the stomach) feeding may need to be used but if it is felt that there is no possibility of improvement then a gastrostomy (a permanent opening into the stomach for food and medication) may need to be considered. For further information you can download a A factsheet entitled 'Gastrostomy: Living with a gastrostomy' from the Institute of Child Health website.
2. Breathing - difficulties in breathing may arise for two reasons:
a) Aspiration as mentioned above.
b) Narrowing of the glottis (this is the opening of the trachea through which air passes on it way to the lungs). This opening is control led by the brainstem. So when the brainstem is affected, the opening may suddenly close from time to time. This results in less air going through the glottis (the area if the voice box); and produces a characteristic sound known as stridor. These attacks can be frightening especially as consciousness is not lost. They tend to get more frequent as the disease progresses, and also more prolonged. Eventually one of these may be so severe as to be fatal. The management of these attacks can be very difficult. In particular, the knowledge that the child is aware of what is happening and may be frightened can be very distressing for the parents. So it may be appropraite to consider a tracheostomy (the surgical creation of an artifical airway in the windpipe). For further information you can download a factsheet entitled Tracheostomy: Living with a tracheostomy from the Institute of Child Health website.
3. Anti-convulsant drugs to control fits and antibiotics to treat infection may be prescribed.
If you wish to speak to someone who has lost a child through Type 2 Gaucher disease, contact the Gauchers Association who will put you in touch with other members who have had a child with Type 2 Gaucher disease.
A book Twinkle, Twinkle Little Star written by Catherine North who describes in diary form how she had and lost a daughter at 7 months though Type 2 Gaucher disease. The book is available free of charge from the Gaucher Association or you can download it here.