How the illness affects people
Alport Syndrome is a genetic condition that mainly affects the kidneys and hearing. Women are usually less severely affected than men and are more likely to only be carriers of Alport Syndrome. Some people will be the first in their family to show symptoms. For others it will be inherited from a previous family member.
Hearing difficulties in boys are usually first noticed around the age of ten. That is around the same time that they start to show signs of kidney disease. A hearing test (audiogram) at this time will reveal hearing loss for high-tones while the ability to hear lower frequency sounds is less affected. We need high frequency hearing to understand speech. Hearing aids are therefore a good idea, especially for school or college. Once hearing loss has started, it usually slowly worsens over a period of ten years or more. As hearing is normal at birth and during early childhood, speech develops normally. Overall hearing loss is moderate and it is unusual for an Alport patient to become completely deaf.
One of the early signs of Alport Syndrome is having blood in the urine. In children, particularly boys, you can sometimes see the blood mixed into the urine. This occurs without any pain. At other times the blood is present but in such a small amount that it is invisible and only detected by a stick test, or by looking at the urine under a microscope. Urine tests may also find protein in the urine, and these urinary findings help doctors to consider the diagnosis. The abnormal urine tests occur long before there is any problem with kidney function.
Most men with Alport Syndrome develop kidney failure in their twenties or thirties. Women tend to develop hearing problems later than men and are less likely to get kidney failure, although both can still happen in later life.
Some people with Alport Syndrome also have eye problems. These are usually minor and easily treated. They tend to occur in adults rather than children, and rarely lead to problems with vision. Small white flecks can sometimes be seen in the eyes. These have no effect on vision but can help in the diagnosis of Alport Syndrome. In some Alport patients the lens of the eye becomes cone-shaped. If this becomes a problem, the lens can be replaced. This is like a cataract operation.
What can be done about it?
Alport Syndrome is usually diagnosed by carefully reviewing the family history, testing the hearing, and checking the urine and kidney function. Confirmation is often made using a kidney biopsy.
Because Alport Syndrome is genetic, it can be helpful to test for abnormalities in the genes known to cause it. If a genetic fault is found, other family members can be tested to see if they are likely to be affected, or if they could pass the gene on to their children.
There is recent evidence that a simple treatment can slow down the disease in the kidneys. This is why it is now useful to make the diagnosis as early as possible. The treatment uses a well- known type of medicine that lowers blood pressure, called an Angiotensin Converting Enzyme (ACE) inhibitor. It reduces scarring in the kidneys so that they last longer. Side effects are rare, and usually a dose and make of ACE inhibitor, or a related drug known as an Angiotensin Receptor Blocker (ARB), can be found that is acceptable for long term use.
Decline in kidney function is not noticed by a patient until very late in the course of the illness. This is why it is important to have regular health checks where the level of kidney function will be worked out from a simple blood test. Various lifestyle adjustments can then be made that are appropriate to the stage of kidney function. For example, keeping good control of blood pressure, ensuring good nutrition and preventing anaemia can all help to maintain wellbeing.
The different stages of chronic kidney disease (CKD) are based on levels of kidney function, ranging from mild to severe. If a patient approaches severe kidney failure, preparations will be made for renal replacement treatment. This may consist of dialysis or transplantation. Patients with Alport Syndrome usually respond well to transplantation and the condition does not recur in the new kidney.
How the disease works
Each kidney contains about a million tiny filters called glomeruli that filter the blood stream. During the filtering process, fluid passes through the glomerular basement membrane which is made up of a fine mesh of collagen fibres. In Alport Syndrome one of these fibres, Collagen IV, is either faulty or missing because there is an error in one of the genes responsible for its production. Without normal Collagen IV, the filtering membrane is weakened. The body attempts to repair the weakened filters, however, over time they become scarred and can no longer function. Kidney function will then decline.
Collagen IV is also essential in the inner ear in the cochlear membrane. This transmits sound vibrations to the nerve sensors in the ear. The weakening of this membrane eventually leads to hearing loss.
Carriers of Alport Syndrome
Carriers are people who have one abnormal copy of the Alport gene, and another normal copy. Mothers of boys with Alport syndrome, for example, are always carriers.
Women who carry the disease on one of their X chromosomes usually have no or only minor kidney trouble. Tests often show small amounts of blood, and sometimes protein in their urine. However some are unlucky enough to get more severe disease and develop kidney failure. The lifetime risk of getting significant kidney disease for women who carry Alport’s may be as high as 20-30%, but most never get severe trouble, and those who do are usually much older than men who are affected.
AlportUK (www.alportuk.org) is a patient-led organisation dedicated to empowering people living with Alport Syndrome to enjoy the best possible quality of life.
The website of the Edinburgh Renal Unit (EdREN) (www.edren.org) contains a wealth of information on Alport Sydrome, including detailed overviews of the condition, information on normal kidneys and Thin GBM disease, which is often related to Alport Syndrome.
The National Registry of Rare Kidney Diseases (RaDaR) is a database of patients with a variety of rare kidney conditions, including Alport Syndrome. It is used to help improve understanding of these conditions and to find suitable participants for research trials into new treatments.
This information was written by the Alport Syndrome Rare Disease Group, in partnership with the Renal Association.