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When someone has Phelan-McDermid Syndrome (PMS) it means that they have learning difficulties, problems communicating and may take longer to learn how to walk. They may also have behaviour which challenges.

What is it like for siblings if their brother or sister has Phelan-McDermid Syndrome (PMS)?

Lots of siblings have really good relationships with their brothers and sisters who have PMS. However, other siblings may feel left out because their brother or sister with PMS needs lots of time and attention from a parent. They may feel frightened if their brother or sister display behaviour that challenges and worry in case they get hurt. They may also feel guilty that their brother or sister has PMS but they don’t.

What causes PMS?

PMS is a genetic condition that someone is born with. It can be passed from a parent to a child before they are born but it cannot be caught like a cold. In some families it will affect some children but not others.

What does it mean?

PMS affects children in different ways. They may have low muscle tone, delayed speech or not be able to speak at all. They may be autistic or have ‘autistic like’ behaviour. They may have teeth grinding, chew lots of different things, may not be able to feel pain or may display behaviour that challenges. A lot of children will find it hard to sleep.

What treatment is there?

There is no cure for PMS. It is a lifelong condition but there are things which may help such as

  • physiotherapy
  • occupational therapy
  • speech and language therapy

Most people with PMS will need extra help all their lives.

Information approved by the Phelan Mcdermid Syndrome Society UK March 2024