Congenital deafblindness
Rubella
In the past, the leading cause of congenital deafblindness was rubella, a highly infectious viral illness (also known as German measles).
If a pregnant woman gets rubella, it can cause serious damage to her unborn baby, particularly to their eyes, ears and heart.
However, since routine rubella vaccination was introduced in 1988, and due to the success of the MMR (mumps, measles and rubella) vaccine, the number of babies affected by rubella has fallen dramatically.
Premature birth
Problems associated with premature birth are a common cause of deafblindness. As smoking and excessive alcohol consumption are major risk factors for premature birth, you should avoid both, particularly if you are pregnant.
If you do choose to drink while pregnant, do not drink more than 1-2 units of alcohol once or twice a week. Avoid binge drinking and getting drunk, because heavy drinking is associated with a low-birthweight baby and increases the risk of serious birth defects. A unit of alcohol is equivalent to half a pint of normal-strength lager or beer, a small glass of wine, or a single pub measure (25ml) of a spirit.
Genetic conditions
Some rare genetic conditions can also cause deafblindness, either at birth or in the early years of childhood.
One such condition is known as CHARGE syndrome (see Useful links), which is very rare, affecting about 1 in every 10,000 births. CHARGE syndrome causes a pattern of related birth defects that affect the eyes, heart, nose, genitals and ears, as well as restricting a child's growth.
Acquired deafblindness
Conditions that can lead to both the loss of vision and hearing are rare, but not unknown.
Usher syndrome
The most common condition that causes acquired deafblindness is a genetic condition known as Usher syndrome (see Useful links), which affects around 1 in every 25,000 people.
Children with Usher syndrome are born deaf and then develop a condition known as retinitis pigmentosa as they become older. Retinitis pigmentosa causes the retina - the part of the eye that responds to light - to slowly deteriorate. Eventually, the retina loses the ability to transmit information to the brain and blindness can occur.
Other causes
Acquired deafblindness can often occur as a result of two unrelated conditions that cause loss of vision and loss of hearing, or it can occur as a result of ageing.
For example, as we get older, our vision can get worse as a result of the cells at the centre of the retina deteriorating. This is known as age-related macular degeneration. A similar process can also happen with our hearing, as the cells within the inner ear that help transmit information to our brain become damaged or deteriorate.
