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Leukodystrophies

I was caught rather than saved by the bell. Myelin is the name of the white matter that forms the insulating coating around the nerves. It acts as an electrical insulator and speeds up the transmission of electrical impulses along the nerves by effectively allowing the nervous impulse to jump from one point on the nerve to another. When the myelin sheath is absent or damaged, the raw nerve cannot sustain the electrical impulse and it is lost. ““Leukodystrophy”” derives from the Greek words that mean—I paraphrase—““white stuff behaving badly.”” Leukodystrophies are a group of genetic disorders that are characterised by the imperfect development or poor maintenance of the myelin sheath. In simple terms, one can envisage the myelin sheath as resembling the insulating cover of an electrical wire. If that is frayed or cut, the electrical current loses its ability to reach the intended appliance or even shorts out. The same applies in our bodies: if the nerve is not insulated properly, the brain sends a message to the intended appliance, such as a muscle, but the message loses its way and fails to get through. We lose mobility, capability and even life. In more complex terms, leukodystrophies go by the names of adrenoleukodystrophy or ALD, which is one of most common forms; metachromatic leukodystrophy; Krabbe disease; Pelizaeus-Merzbacher disease; Canavan disease; childhood ataxia with central hypomyelination, better known as CACH or vanishing white matter disease; Refsum disease; cerebrotendineous xanthomatosis, also known as Van Bogaert-Scherer-Epstein syndrome, and Alexander disease. That is to name but a few of the 36 conditions that fall under the definition. Alexander disease goes by at least eight different clinical names, with which I will not detain the House. Multiple sclerosis is not a leukodystrophy. However, I mention it because we have all met someone with MS and we recognise the condition when we see it. For ease of enlightenment, it is worth pointing out that MS is caused by the degradation of the myelin sheath of axons—the long nerves—that connect the central nervous system to the muscles. In that respect, its symptoms are practically identical to some leukodystrophic conditions. The most significant difference between the two is that MS is thought to be caused by an immune system malfunction rather than a genetic disorder. Each leukodystrophy is the result of a unique genetic defect in a gene that causes the breakdown of myelin in the brain and nervous system. A child with a leukodystrophy is usually born with normal myelin and he or she develops as a healthy, intelligent and lively child. Some children may reach the age of 12 before the deadly disease kicks in and becomes apparent. Only then, when the symptoms manifest themselves, do the families start to find out anything about the time bomb that is ticking in their child’s body. Those children might, by the age of 12, speak multiple languages or excel in sports or school. They might be potential business leaders, diplomats or shop assistants. They might enjoy reading, climbing or computer games. They might be good at chess, maths or science. They are all ordinary children, covering the whole range of aptitude, ability and personality. Months later, as the hereditary condition takes hold, they may have lost their ability to walk, talk, hear, see, stand, sit and swallow. Eventually, they inevitably lose the ability to sustain life itself. The cruelty of the diseases is that the children who suffer become prisoners in their bodies. Their intelligence remains intact, but they become unable to communicate or function. Just as brutal, the parents are left helpless and hopeless as all they can do is watch their child die. Unfortunately, one thing that all leukodystrophies have in common is that, once the symptoms become apparent and it is clear that something is wrong, it is too late to rescue the child. However, it is possible to make a difference for these children before the symptoms become apparent and steal their young lives away. Ignorance might be bliss, but knowledge is power for these families. If we introduced universal newborn screening for these leukodystrophic conditions, the families could know what the situation was before the symptoms took hold of their child. With some leukodystrophies, treatment is available—but only, as I said, if it is administered before the symptoms appear. For example, Lorenzo’s oil is used as a treatment for ALD and is available on the NHS. There is a proposed course of enzyme replacement therapy for storage disorders such as Krabbe’s disease or metachromatic leukodystrophy. There is also the possibility of bone marrow transplants to address other leukodystrophies. All those treatments could give back the chance of life that is the right of each and every child—but only, I say again, if they are administered before the disease takes hold. ALD is a genetic condition linked to the X-chromosome, so it is typically found in boys. Its three phases are described as Addison’s disease, followed by childhood dementia and then a permanent vegetative state. Typically, ALD is diagnosed between the age of four and eight, and death will come within five years of diagnosis. Lorenzo’s oil is a medicine named after Lorenzo Odone, an American boy who was diagnosed with ALD 20 years ago. The oil was found to prevent the process of demyelination and thus prevent the damage that this particular gene malfunction causes. I had the pleasure of meeting Lorenzo’s brother just a few weeks ago when a delegation of supporters came to Westminster to see me deliver the petition—with 5,500 names—on their behalf. Many Members will be familiar with the work of Lorenzo’s sister—the journalist, Cristina Odone—who wrote about her brother’s condition in The Observer a few weeks ago. Even Lorenzo’s oil, however, is effective only if the treatment is applied early enough. Indeed, it is recommended only for pre-symptomatic cases, which can be diagnosed only through genetic screening. I guess that such screening happens today only if there is a family history of the disease. Lorenzo’s oil is presently the subject of clinical trials in America, so it is not as widely used yet as it might be. For any anoraks who may be listening, Lorenzo’s oil is also known as ““4:1 glyceryl trioleate-glyceryl trierucate””. You, Mr. Deputy Speaker, can meet Lorenzo on the Myelin Project website. He is now 28 years old. He has lost most of his bodily functions, but his mind is still there. He communicates through blinking his eyelids to say no and wiggling his fingers to say yes. He enjoys music and being read to. The website says:"““Lorenzo will not regain his speech or full mobility until we are successful with remyelination””." Discovering treatment to reverse the demyelination of nerves caused by leukodystrophies is one of the aims of the Myelin Project, which has already commissioned around 40 pieces of research at a cost of $4 million—principally in America. One in every 17,000 babies will have ALD like Lorenzo. Some will take months or years to reach a suitable diagnosis. Very few will live to Lorenzo’s age. The birth rate of children affected by other leukodystrophies ranges from one in 10,000 for Krabbe’s disease to one in 40,000 for MLD. Although each leukodystrophy may be a rare disease, when the birth rate of all 36 is combined, it becomes a potentially public concern. Already every year, the NHS spends about £65 million on the diagnosis and palliative treatment of demyelinating diseases such as the leukodystrophies. Far more expensive than that is the time that is spent by families in weeks, months and sometimes years of caring, not knowing why their child is slipping away and dying. When any child is born in the UK today within the NHS, a nurse pricks the heel and takes blood to test for a number of medical conditions. One of these is actually a leukodystrophy, phenylketonuria, often known as PKU. If it is not treated, PKU creates severe, and often permanent, brain damage, although this can be countered through a strict dietary regime during the child’s developmental years. After the age of puberty, the risk of damage is minimal, and the young person can go on to live a normal life. Without that dietary regime, however, considerable brain damage is certain, so in this case the argument for neonatal screening has not only been made but has clearly been accepted by the NHS. Belle Humphrey is the parent of a child who lives in my constituency. She works for the Myelin Project, and with other campaigners and organisations, and it was they who put together the petition that I presented to Parliament a few weeks ago. All that that petition is asking for is that the NHS should use the blood that it already collects from heel pricks to test for the other 35 known leukodystrophies. We are not asking for further samples to be taken from the babies. As I stated before, early detection can lead to life-saving treatments which can give children their lives back before these diseases steal them away. Testing would also identify genetic carriers of these diseases and potentially, through genetic counselling, make a real difference for the future. Some conditions such as ALD are carried on the X chromosome, but female carriers can show a mild form of the symptoms. They too would need treatment. Much of the language that I have used in this debate takes me back to the genetics that I studied at university, but it must be said that some leukodystrophies are auto-recessive and can occur through spontaneous mutation, so a child can be born with one of these disorders without there being any evidence of a previous family history. In some cases, a child may develop the symptoms of the disease or even die before the parents discover that a younger brother or sister also has the same disease. Ignorance allies itself with fear in these cases; even worse than losing one child from such a devastating disease is the prospect of losing another, or even all of one’s children. In one family that I have heard of, a very active son was winning medals in show-jumping and travelling around the world, learning languages and showing great promise for the future at the age of 12. Then, during treatment following an accident, it was discovered that his brain was losing myelin due to adrenoleukodystrophy. As ALD was known to be an hereditary disorder, the doctors immediately suggested testing other members of the family. They discovered that his 15-year-old brother was also affected by the same deadly condition. Within two years, the 12-year-old went from enjoying an active lifestyle to blindness, an inability to walk and, sadly, death. However, his brother’s condition had been spotted in time. It was discovered before the symptoms appeared in him, and he is now receiving treatment and leading a normal and healthy life. Luckily for him, his condition was caught in time, and that prevented another devastating loss for that family. We know of about 100,000 people in Britain today who are affected by demyelinating diseases, but there will be many more who are suffering, so far, in silence. A study released in America suggests that about one in 20 cases of sudden infant death syndrome might be attributable to one leukodystrophy or another. Leukodystrophies do not distinguish between geographic, ethnic or gender boundaries; they take away the lives of children and devastate families in every walk of life. I want to thank Belle Humphrey and her friends for educating me about the cause of families with children with leukodystrophies and, indeed, for assisting in the research for this speech. Preventable diseases are not being prevented here in the UK, and that must be a matter of national concern. The situation requires attention before another family is faced with a devastating situation. Universal newborn screening programmes are already in place in the USA and in some countries of Europe that are also addressing the issue. The cost of a screening programme over the long term—merely adding another test for the blood samples that are already being taken—will be far less than the cost of treatment if screening is not used. Our country and our NHS should set the standard in Europe and help these families now. Newborn screening for leukodystrophies is not expensive. It is not difficult. But it is the right thing to do. I ask my hon. Friend: will he say yes to the testing of blood for genetic evidence of the existence of leukodystrophies in babies so that they can receive treatment that will prevent their inevitable early death, should this sad condition be found?