There are between 4,000 and 6,000 diagnosed genetic disorders. It is estimated that one in 25 children is affected by a genetic disorder and therefore 30,000 babies and children are newly diagnosed in the UK each year.
Some genetic disorders are apparent at birth while others are diagnosed at different stages throughout childhood, and sometimes into adulthood.
Here are just a few of them:
Down’ syndrome is a genetic disorder that was named after John Langdon Down, the doctor who first recognised it as a distinct condition in 1866.
Down’s syndrome affects a baby's normal physical development and causes moderate to severe learning difficulties. It is a lifelong condition that happens at conception when the cells first divide.
Children who are born with Down syndrome also have a higher chance of developing other conditions, some of which are life-threatening. For example: congenital heart disease, sight & hearing problems and Alzheimer’s disease.
The cause or causes of Down syndrome are unclear, but the single chance of the condition occurring seems to be the age at which a woman gives birth. The older a woman is when she has a baby, the higher the risk of her baby having Down syndrome.
The outlook for Down syndrome can vary widely, depending on whether a child with the condition also develops any other serious health conditions. Children with Down syndrome are most vulnerable during the first year of their life but after the first year of life, the outlook improves dramatically. Due to advances in treatment, the average life expectancy for a person with Down syndrome is around 50-plus and many people live well into their 60’s and 70’s.
Hypohidrotic ectodermal dysplasia (HED)
Hypohidrotic ectodermal dysplasia - also known as "Anhidrotic ectodermal dysplasia and “Christ-Siemens-Touraine syndrome” - is one of about 150 types of ectodermal dysplasia in humans. Before birth, these disorders result in the abnormal development of structures including the skin, hair, nails, teeth, and sweat glands.
Hypohidrotic ectodermal dysplasia is an extremely rare genetic condition, affecting around 7,000 people.
Sufferers have light and sparse scalp and body hair, a reduced ability to sweat and the congenital absence of teeth. These features become obvious during childhood.
As sufferers find it difficult to sweat the condition can cause hyperthermia unless the temperature of their environment is carefully controlled.
Physical growth and movement are unaffected by the condition. HED can be diagnosed after infancy on the basis of physical features. There are no 'cures' for the condition but symptoms can be managed. Parents of affected children do all they can to give their offspring as normal a life as possible. This, obviously, includes socialising with other children.
Phenylketonuria (PKU) is a rare genetic condition present from birth (congenital). In PKU, the body is unable to break down an amino acid called phenylalanine which then builds up in blood and in the brain.
Left untreated, high phenylalanine levels damage the body's central nervous system, the brain, and can cause severe learning difficulties.
PKU is treated by a restricted low protein diet which is extremely low in phenylalanine and supplemented with essential nutrients. The diet should continue for life but particularly when the child is growing. The aim is to keep the blood phenylalanine level within a specific target range.
PKU is a rare condition. It is estimated only 1 in every 12,000 babies born in England will have PKU. Both sexes are affected equally by PKU. The condition is slightly more common in white people, particularly those of Celtic descent (Scottish, Irish and Welsh). It is very rare in black people and those of Japanese descent.
Angelman syndrome is a rare genetic condition that affects approximately 1 in 25,000 people. It affects the nervous system, causing severe physical and intellectual disability, with symptoms becoming noticeable from early childhood.
In most cases of Angelman syndrome, the genetic abnormality responsible for the disorder happens by chance around the time of conception. This means the disorder is not usually inherited. There are, however, a few families where the condition is inherited and brothers and sisters may be affected.
Most children with Angelman syndrome are diagnosed between the ages of 18 months and 6 years, when the typical physical and behavioural symptoms are noticed. A blood test can be carried out to look for one of the genetic abnormalities that cause Angelman syndrome.
A child with Angelman syndrome will have the following signs and symptoms:
A child with Angelman syndrome will also display distinctive behaviours, these may include:
Many children with Angelman syndrome will have an abnormally small head by the age of two, and many will develop seizures around this age.
Many of the typical features of Angelman syndrome happen because the gene called UBE3A on chromosome number 15 is not functioning in the normal way.
With age, people with Angelman syndrome become less hyperactive and the sleeping problems tend to improve, although their frequent smiling persists. People with Angelman syndrome will have a near-normal life expectancy, but will need looking after throughout their lives.
For more information visit: http://www.geneticdisordersuk.org/