These pages pull together current information on Leber's Hereditary
Optic Neuropathy (LHON) , also known as Leber's Optic Atrophy (LOA) , Leber's
Optic Neuropathy (LON) or Leber's Disease. It is often referred to as just
Leber's for short.
Although I've tried to keep these pages readable for people without a scientific background, the information is taken from scientific research and sometimes I have identified specific technical papers for those who want to read them. They are also informally reviewed by scientists researching into LHON in the UK. The LHON Links page also contains a great many references to scientific papers giving case reports and other research results which have contributed to this information.
I have grouped the information on LHON into chunks based on typical questions asked about LHON. Click on these "Frequently Asked Questions" to learn more about LHON.
Social Network Sharing
A key way in which patients and their families can help is by adding their details to patient registers including the North American Mitochondrial Disease Consortium Clinical Patient Registry and Rare Diseases Clinical Research Network RDCRNpatient registers. Doing this gives patients the opportunity to take part in trials or research working to better understand mitochondrial disease.
When someone loses eyesight due to LHON, it is a huge emotional and psychological blow. The physical impact is loss of central vision. This means that everyday things we take for granted become difficult or impossible. Reading, driving a car, recognizing people in the street, meeting friends, reading a menu, buying something in a coffee shop....the list seems endless.
During or soon after the eyesight loss, the person will be going through the stages of loss or grief. They may not happen in this order, and some stages may reappear. These stages can also affect close relatives and friends. These are all normal emotional states which anyone can feel.
The person cannot accept or believe that the situation is real. They are trying to deal with the shock of the new situation. This is a deep-seated emotional denial, not a rational decision to ignore the facts. It may be the mental equivalent of the shock reaction to a physical injury - the person does not feel pain at first because the body's defense mechanism is geared up to escape the situation. A while later they start feeling the aches and pains of the injury.
Sometimes part of Denial, it is natural for the person to feel alone - that no-one else is going through the same situation, with the same reactions and feelings. This is particularly the case for someone with LHON, as it is a rare condition.
Not just anger at the frustration of dealing with everyday problems, this is an underlying Anger at the world - it can be directed at anyone and anything. Life seems so unfair and unjust. This can be a difficult thing for friends and family to deal with, as they may become the targets of the Anger. There is no easy way to deal with this situation, it is the highly charged emotions of grief finding a way to express themselves.
As a stage in the grieving process, this is an emotional state where a person feels that they need to explain and get some control over the situation.
This may be felt as a need to explain the LHON and find some trigger for the symptoms "it was brought on by drinking too much", "if only I hadn't taken up smoking", "Maybe that drug my doctor prescribed triggered it?". It may lead to people trying to make deals with themselves or with God - "If I start going to Church regularly again things will get better", "If I become a better person my eyesight will be saved".
As scientists learn more and more about LHON, and start to experiment with possible future treatments, these deeply held feelings will be supported by information, medical tests and eventually practical therapies.
The future can seem very bleak, combined with deep feelings of isolation, frustration and anger. Even if support is offered by family and friends, someone may be emotionally incapable of accepting it while in this phase of their loss. Even though there is a physical cause and reason for their pain, someone with LHON may get great benefit from psychological therapies such as CBT. These can give someone a set of psychological tools to monitor their emotional state and work through periods of depression. Friends and family can be a huge help during these times. The amount and type of support that works will vary a lot - sometimes practical help is needed, sometimes being someone to listen, provide a hug or even just being there.
This is a mental state of emotional calm and tranquility, rather than a fatalistic state of hopelessness. Unlike Depression, the person can take an interest in life, be positive about future plans and deal with practical problems.
At the moment there is no single list of people in the UK or Ireland affected by LHON.
A major problem for researchers looking at treatments for LHON is getting in touch with affected families. It is very difficult for a research team to find LHON patients or people with a LHON gene to help in their research. Probably the biggest single thing anyone with LHON can do to help find a cure is to provide their contact information to a research team. Providing your contact details never commits you to anything in the future, but it does mean that you are kept informed.
Researchers may want to talk to LHON patients, collect family history data, or may sometimes want to take small samples. so that the DNA can be analyzed. Whatever the case, your involvement is always voluntary and you can opt out whenever you wish.
Being in touch with a research team also means that LHON patients will be informed about treatment trials and may be invited to take part.
Someone in the UK or Ireland affected by LHON or related to a LHON patient can help research by adding their details to the LHON Register .
Having a list like that would be a huge help to researchers at the Wellcome Trust Centre for Mitochondrial Research in Newcastle.
As a first step to building this list I have added a form to this site.
It is also a step towards forming a new group to represent everyone affected by LHON in the UK and Ireland , working closely with the doctors and researchers at the Centre who are actively working on developing effective treatments.
This invitation is open to people who have lost eyesight due to LHON and their families.
Please add LHON person information here
You can directly support research into LHON at Newcastle University through the James Ferguson Fund.
A major fund supporting research into the treatment of LHON is the United Mitochondrial Disease Foundation (UMDF) LHON Project Fund
Irish Research into developing Gene Therapy for LHON is now funded by the Health Research Board (HRB) and the Medical Research Charities Group (MRCG). It was initially funded by the Irish charity Fighting Blindness
The International Foundation for Optic Nerve Disease directly supports research into LHON and you can give on-line via the IFOND Just Giving page
There are two documents based on this site:
A very brief patient booklet (5 A4 pages) and a much longer book of the detail in this site (about 70 A4 pages).
An excellent book written and compiled by people affected by LHON, telling their own stories.
Buy from Amazon.co.uk
Buy from Amazon.Com
As research into LHON is going on right now, in laboratories around the world, any information about LHON cause or treatment in a textbook is likely to be out of date. The best place for up-to-date information is in the highly technical peer-reviewed scientific journals.
Any significant new information on LHON will be used to update the relevant section of this site, and is likely to appear on the other LHON sites, as well as being discussed on the LHON Facebook Group.
You should always consult your own medical practitioner and ask them to explain the information to you.
The rest of this page gives some information about LHON, but this is laid out more clearly, with more detail in the answers to the Frequently Asked Questions listed above.
This single page is not intended to be a full description of Leber's Hereditary Optic Neuropathy - I strongly urge you to look at the other pages on this site listed in the Frequently Asked Questions to get more information, and to get involved in the LHON on-line community.
Leber's Hereditary Optic Neuropathy is a rare condition which can cause loss of central vision. It usually affects men, most commonly in the twenties or early thirties, but the symptoms can happen at any age, to men or women.
The disease was first described by the German eye specialist Theodore Leber in 1871. He studied and described more than one condition, so it is important to make sure that any information you find is for LHON, and not another unrelated condition such as Leber Congenital Amaurosis (L CA).
Although LHON was known to occur in families, the details of LHON inheritance were not worked out until the late 1980's. We now know that LHON is inherited through the mother's (Maternal) mitochondrial genes.
People affected by LHON carry at least one of the LHON-causing genes, but only a tiny percentage of people carrying a LHON-causing gene lose any eyesight.
We do not yet know why most people can carry a LHON gene without losing any eyesight, or why many more men lose sight than women. Researchers are trying to find answers to these questions. It may be that there are other genes involved, and someone has to inherit a combination of genes before their eyesight is affected.
Although we know that affected people have damaged Optic Nerves, we have not yet identified the exact mechanism or link between carrying a LHON causing gene and the damage to the optic nerve. It is likely that the LHON genes reduce the nerve's ability to generate energy from food.
At present doctors can't tell if a particular person carrying a LHON gene will lose any eyesight before symptoms begin. The first sign of LHON is the loss of central vision.
The illness usually occurs in men, although some women can be affected. There are about 9 affected men for each affected woman.
About 1 in 30,000 people carry a LHON-causing gene in the UK but only about 1 percent of these ever develop any symptoms.
Once a member of a family is diagnosed as having Leber's Hereditary
Optic Neuropathy (LHON) then some other members of the family are known to be
potential sufferers or carriers ("At risk"). This includes siblings and maternal relatives of the affected person, but man cannot pass on a LHON-causing gene.
Most people carrying one of the LHON genes do not lose any eyesight. There is at present no way of predicting whether or not an "at risk" person will
develop symptoms of LHON. Not every "at risk" individual becomes a
Only women can pass a LHON gene on to their children, men cannot pass on the disease.
Eyesight can deteriorate over a period of hours to months. Both eyes
are typically involved, although to varying degrees. Very rarely
eyesight may improve or recover.
The central vision is lost, where we see detail and can distinguish colours best. People affected by LHON are usually left with some peripheral vision.
Most LHON sufferers are registered (legally) blind, although many retain some useable eyesight , i.e. they can move around in familiar surroundings without any trouble but cannot drive a car or read without magnification aids.
Typically, sufferers cannot recognise people in the street, although
they may be able to make out moving shapes as they approach. Ordinary
eyeglasses or contact lenses are of no practical help as they alter the focusing of the eye.
There are many kinds of aid which can help someone affected by LHON.
Low Visual Aids to help with reading are available from the National Health Service and other sources. See the separate Vision Aids section.
Leber's Hereditary Optic Neuropathy was first described by Theodore Leber in
the 19th century, but we only really started to understand the inheritance and
cause of Leber's in the late 1980's.
Since then researchers have learned a great deal about Mitochondria (the energy-providing parts of the cell), Mitochondrial Disorders and LHON.
In a lot of cases, the change in DNA that leads to LHON is new, and did not exist in the person's grandparents, aunts or uncles. It is a normal part of the usual DNA copying process that the copying doesn't always make an exact copy, so a child's DNA will be very, very similar to his/her parents, but not absolutely letter-for-letter identical.
Once this change happens to DNA of a woman, it can be passed down through a family to her children, grandchildren and so on.
That is why we get a lot of cases of LHON around the world with no other family members affected, and we also get cases where many people are affected over several generations.
Not everyone in a family affected by Leber's will lose their eyesight, and we
do not yet know how to tell who will get symptoms.
We do know that Leber's is inherited through a gene which is only passed on
through the egg cell from the mother. Men cannot pass on Leber's Hereditary
Optic Neuropathy to their children.
Men with LHON do not pass it on to their children, whether boys or girls. A woman carrying one of the LHON genes will pass it on to all of her children, both boys and girls. This means that each of her children is at risk of developing symptoms of LHON. There are some detailed figures on this risk in the FAQ (Frequently Asked Questions) Section of this site.
LHON is a Genetic Disorder - that means it is caused by a faulty Gene inside us, not a bug which can be caught like the common cold.
So what is a Gene?
For many years scientists talked about Genes but didn't actually know what a Gene physically looked like. They studied Genes by looking at the way certain things were passed down the generations of a family. If they saw that Blood Group was passed down from the parents, they said it must be controlled by a Gene Anything passed down, or inherited, from the parents, was allocated a Gene so that we could study and analyze the way it was passed on.
Then came a huge breakthrough - we discovered that this mysterious thing called a 'Gene' actually does exist physically in the Human body. Every Human Gene is held as a chemical called DNA. Each piece of DNA can hold hundreds or even thousands of Genes.
Inheritance is controlled by this special Chemical called DNA. This is found in very tiny structures called Chromosomes, and most of these are grouped together into the Nucleus of each cell in the human body. This is the DNA which controls pretty much everything we normally think of as inherited - Sex, body shape, Blood Group, height, skin, hair eyes and so on.
Each cell has one Nucleus, that is one copy of the DNA which plays such a big part in who we are.
Each cell also has thousands of little structures called Mitochondria. (Pronounced Mite-oh-kon-dree-ah)
These structures are the 'power houses' of the cell. Each cell needs energy to do work, and it is the Mitochondria that provide the energy from the food we eat. Different kinds of cell do different kinds of work.
All of these cells use the Mitochondria inside them to get their energy from the food given to them via the blood supply.
All of the Mitochondria in a human body come from the Egg cell of the person's Mother.
There is one thing very special about Mitochondria. The DNA which controls how Mitochondria work and how new Mitochondria are built is NOT held in the Nucleus.Every single one of the Mitochondria has its own little chromosome and its own special set of DNA.
We now know that Humans carry two separate sets of Genes held in two separate sets of DNA.
Of the two, Mitochondrial DNA is much, much simpler. It only holds the information needed to build the Mitochondria and make them work. That is, it controls how good our Mitochondria are at getting energy out of our food.
But this is a crucial function - if a cell can't get enough energy, it can't work properly.
Leber's Hereditary Optic Neuropathy is linked to a number of genes, all in the
DNA of the structures called Mitochondria. These provide energy to the cells of the
body. We believe that the particular gene changes linked to Leber's Hereditary
Optic Neuropathy lower the amount of energy available to the cells of the optic
nerve and retina. These cells are damaged and can even die because of this lack
of energy. The damage to the optic nerve and retina is what causes the symptoms
Every person affected by LHON has a defect in the DNA of their Mitochondria. This defect means that the Mitochondria is a lot less efficient at getting energy out of food.
This defect may not be in the DNA of the person's mother. It could have happened while the egg or the embryo was developing. Scientists call this a 'spontaneous' case of Leber's and there is no family history of the condition.
Alternatively, the defect may have happened in the person's Mother, her Mother, Her Grandmother or many generations back. LHON may or may not be seen in the family tree, because not everyone with the defective Gene develops LHON.
In fact figures so far suggest that something like half the known cases of LHON have no family history and have come about from 'spontaneous' changes.
This site is for general information only - always consult qualified medical professionals for information and advice on Leber Hereditary Optic Neuropathy.
Persons accessing this information assume full responsibility for the use of the information and understand and agree that James Leeder is not responsible or liable for any claim, loss or damage arising from the use of the information.
No responsibility or liability is accepted for any error or omission.
Including a link or mentioning an organisation, service or product in these pages is not intended as, and does not imply, a recommendation or endorsement.
James Leeder expressly disclaims any representation or warranty express or implied concerning the accuracy, completeness or fitness for a particular purpose of the information.
This page was last updated on 11 Ma;y 2014
Copyright (c) 1997-2014 James Leeder.
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