Why does ald only affect boys

Although females who carry the ALD gene mutation do not develop the full ALD condition, approximately half may develop some symptoms. Because a female has two X chromosomes, if she inherits the faulty gene, then she still has another X chromosome to offset the mutation. However, because males only have one X chromosome, the gene abnormality causes the disease. With each pregnancy, female ALD carriers have a 25 percent 1 in 4 chance of having a carrier daughter and a 25 1 in 4 percent chance of having a son affected with the disease.

Boys with cerebral adrenoleukodystrophy usually begin showing symptoms between the ages of 4 and The most common symptoms include:. Without treatment , ALD progresses rapidly, often leading to a vegetative state or death within a few years. For females, symptoms appear later in life than for males, and are less severe.

We have separate page here for females with the gene , and for males who have developed symptoms of cerebral ALD. Both males and females can pass the gene on to their children. It is run by people who have been personally affected by the conditions, either themselves or in their families, and are here to help you. We also have a worldwide contact list of people who are willing to chat about all aspects of living with AMN.

Finding out that you or a loved one have a serious genetic condition can be devastating news. You may be feeling a whole mix of emotions, and probably feel very confused and fearful about what it all means. You will also have several appointments to attend and meet new professionals which can be daunting, but they are there to help you.

Alex TLC can support you by email, phone, home visits, or through the information on our website. You can contact us on , or email info alextlc. Of course, there is no right or wrong way of dealing with having asymptomatic ALD.

But in researching this information we have spoken to many people who have the ALD gene, and we have put together some of the information they wish they had been given when they were first diagnosed. ALD stands for adrenoleukodystrophy.

It is caused by a fault in a gene called ABCD1. ALD can cause several different conditions, which are described below. As we mentioned in the introduction, males and females are affected differently, and the information in this booklet only applies to males. The good news is that being diagnosed with the gene as a child, before symptoms have appeared, gives young boys the very best chance of avoiding the most severe effects of ALD.

If you have been diagnosed as a teenager or adult, knowing you have the gene puts you and your doctors in the best position to look after your health as you move forward.

Males with ALD have the potential to develop one or more of the three conditions that are related to the gene. A minority may not develop any problems, but unfortunately, almost all males with ALD will be affected in some way during their lifetime, often starting in childhood.

Alex TLC has separate booklets for people affected by each of the conditions — you can find them on our website. Adrenal insufficiency is when the adrenal glands do not produce enough of an essential hormone called cortisol. If it is going to happen, it usually develops before the legs are significantly affected.

It is unusual for men with AMN to develop adrenal insufficiency once they have spastic paraparesis in the legs. Symptoms include chronic fatigue, lethargy, muscle weakness, weight loss, and difficulty recovering from normally mild infectious illnesses.

With adrenal insufficiency you can become extremely unwell very quickly if you get a viral or bacterial infection. A minor viral infection may result in severe vomiting which can lead to dehydration and potentially dangerous changes in blood salts.

This can also happen if you get very stressed, for example by unusually heavy exercise. Adrenal insufficiency is easily treated by taking steroid tablets hydrocortisone with or without fludrocortisone to replace the missing hormones.

If you are diagnosed with adrenal insufficiency you should be given a kit containing an emergency hydrocortisone injection. Your partner, friend or relative will be trained to give you the injection if you are not retaining your hydrocortisone due to vomiting or diarrhoea. Your endocrinologist should give you a letter to show at Accident and Emergency so that you get seen immediately if you need to visit.

Most ambulance services carry the correct medication. You should also wear a medical identity bracelet or necklace saying that you have adrenal insufficiency. That way, if something happens while you are alone the medical services will be alerted to your condition and be able to treat you properly. Cerebral ALD is a disabling and eventually life-threatening condition in which reasoning, speech and mobility are gradually lost. If it is found early, before symptoms appear, it can be successfully treated, especially in boys.

Cerebral ALD can also develop in teenagers and adult men, but this is much less likely. Again, there are no exact numbers. So far, treatment of cerebral ALD has mostly been carried out in children.

A few adults have been treated, but this is an area where research is still going on. The most tried and tested treatment is a stem cell transplant. Previously, this was called a bone marrow transplant; the name change reflects an updated way of obtaining the cells from the donor, but the treatment for the patient is the same. Gene therapy is also in development, but has so far only been used in a few patients.

At the time of writing, a clinical trial of gene therapy is in progress at Great Ormond Street Hospital. Initial results have been promising, but this is still an experimental treatment. For either of these treatments to work effectively it is vital that changes in the brain are picked up at an early stage, usually before any physical symptoms of ALD have appeared. The donor cells settle in the bone marrow and multiply, and some of them move to the brain.

After a time, the healthy cells stop the process of nerve damage in the brain. However, there is a time delay, so the disease may continue to progress for the first year or so after treatment, although usually more slowly than if left untreated.

Transplant does come with risks, but we know many boys who have had a transplant and are living perfectly normal lives. The success rate is increasing all the time however, there is still a risk that boys who have had a successful transplant could develop AMN in adulthood. Transplants in adults who are showing signs of cerebral ALD are not common, but practices are changing. All asymptomatic adults should be able to access yearly MRI scans if they want them.

The risks, procedure and follow-up treatments for transplants are improving all the time, so it would not be appropriate to discuss them in depth in this booklet. If there comes a time when you or your son needs a transplant, your hospital will give you the information you need. Find out more about bone marrow transplants. You can also get support and advice from Alex TLC and from other families who have been through the process. AMN full name Adrenomyeloneuropathy affects the nerves in the spinal cord that carry signals to the legs and lower body.

AMN can start to appear any time from the late teenage years to around the age of The majority of men will have adrenal insufficiency. The ALD gene sits on the X-chromosome. Women have two X-chromosomes, whereas men have an X and a Y. We inherit one of these chromosomes from each parent.

A female who inherits an X chromosome with the ALD gene also has a normal X-chromosome from her other parent. This partially compensates for the genetic fault, so females do not experience the most severe forms of ALD.

Because the gene is so rare, it is extremely unlikely that a female would inherit it from both parents. The diagrams below show how the ALD gene is passed on. X-chromosomes with the ALD gene are shown in red.

ALD is a genetic condition that may be inherited from one or both parents. ALD most severely affects males when it can either present during childhood or during adulthood. Women who are carriers for ALD develop a milder form of the disease during adulthood. Symptoms of ALD often begin between the ages of 4 and 10 but can also present much later in life.

ALD symptoms include:. Adrenomyeloneuropathy is an adult-onset form of ALD that progresses slowly over decades. Symptoms may include a stiff gait when walking and bladder and bowel dysfunction. Many male patients often end up in need of a wheelchair.