In 1965, Dr Harry Angelman first described 3 children with characteristics now known as Angelman Syndrome (AS). He noted all had a stiff jerky gait, absent speech, excessive  laughter and seizures. Other cases were eventually published, but the condition was considered to be extremely rare and many physicians even doubted its existence. Dr Angelman originally called the condition happy puppet  syndrome due to the gait and contented nature of the children.
So what is AS? AS is not a disease, but a neurological disorder that causes severe learning difficulties and although those affected have a normal life expectancy, they will require lifelong care. Most AS children are diagnosed between the ages of 3 and 7, when the characteristic physical and behavioural features become evident. The characteristics used for diagnostic criteria are as follows.
In 100% of cases, there is severe developmental delay. Speech is impaired, with minimal use of words. Receptive and non verbal communication skills are higher. There is movement or balance disorder, usually with ataxia of gait and tremulous movement of limbs. There is a combination of laughter and frequent smiling, with an apparent happy demeanour. They are easily excitable and demonstrate hand flapping movements when so. They are also of a hyperactive nature with a short attention span.
Frequently (80%+) there is delayed and disproportionate head growth, usually resulting in microcephaly. By age 3 they have an onset of seizures.
Other characteristics (between 20 and 80%) include, flat occiput (skull bone), occipital groove, protruding tongue, tongue thrusting, difficulty in  swallowing,   feeding problems when young, wide mouthed, frequent drooling, excessive chewing/mouthing, light skin and hair colour, hyperactive lower limb tendon reflexes, uplifted arm position during movement, increased heat sensitivity, sleep disturbance and an attraction to water Although Dr Angelman was able to describe the clinical features, it wasn't until the late 1980's that genetic research was able to identify a problem on the maternal chromosome 15. The majority of people with AS, like me, have a deletion (I.e. a piece of chromosome 15 is missing), although there are other forms of AS called UPD and mosaic.
It is highly unlikely that genetic research, will ever be able to help those affected, but the incidence of AS is currently on the increase. Possibly this is due to the development of genetic research and the greater chance of being able to identify the problem.
What is certain, is that despite all of this, we as parents have children of character. They adore company. They will always have a smile ready for you, and will usually laugh at your jokes. Although you may encounter problems and issues that others cannot even comprehend, there is no doubt that you will get rewards that others can only dream of.