Phenylketonuria (PKU) transitions in the early years

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Children growing up with phenylketonuria (PKU) need to incorporate health care into their normal routines. Read about encouraging proper development.

Key points

  • Babies and young children are learning new things every day. Encourage your child's development by playing with them and teaching them.
  • As your child grows older, they can learn to do more things for themselves. Give them simple chores to do and encourage them to learn new things.
  • Set up a routine for PKU care, and start teaching your child about "green light" or "go" foods.

What is phenylketonuria (PKU)?

Phenylketonuria (PKU) is an absence or deficiency in phenylalanine hydroxylase (PAH), an enzyme involved in metabolizing or converting the amino acid phenylalanine into tyrosine, another amino acid. PAH deficiency results in high levels of blood phenylalanine and an accumulation of phenylketones in the urine.

Partial deficiency of the enzyme results in hyperphenylalaninemia. In this condition, the child has elevated blood phenylalanine, although it is not quite as high as when there is a complete absence of PAH. In hyperphenylalaninemia, phenylketones do not accumulate.

Transition through the years

Children go through many changes as they grow up, including how they think, what they like, and how they take care of themselves. Big changes are often called transitions.

A child must go through a transition in health care when they are diagnosed with PKU. The family and the health care team can help them learn good health care habits, the same way they help them learn other life skills. A child who learns good health care habits will probably have good health habits and attitudes all their life.

This page will help you think about age-appropriate goals for your child. It will give you ideas to help your child become more confident and independent in life and in their health care. It also includes extra goals for children with PKU.

Each child has different abilities from other children. Your child may surprise you with what they can do. Expect good things from your child and encourage them to expect the best from themselves.

Birth to two years old


Help your child develop their sense of independence by letting them explore by mouth, touch and crawling.

Help your child develop trust by making their surroundings safe.

Begin to set limits with your child.

Take short breaks from your child to renew your energy.


Take part in community activities like the Early Years Program.

Take your child to playgrounds and parks.

Talk with parents of other children with PKU and with parents whose children do not have PKU.

Cognitive (learning) development

Encourage situations where your child can learn by looking, touching and mouthing.

Help your child imagine things and keep images in their mind by playing games like peek-a-boo.

Help your child learn words by talking about and naming things around you.

Life skills

By age two, begin to teach your child everyday skills like brushing teeth and getting dressed.

Give your child very simple chores, for example, "Go get your shoes."

Teach your child what "no" means. This will be helpful when they are older.

PKU care

Take blood spots once a week until your child is two years old.

Visit the PKU clinic to see the dietitian and nurse when you need to. Contact them for results of blood spots.

Keep a record of your child's diet and PHE levels.

Follow the special diet prescribed by the dietitian.

Ask questions to be sure you understand what is happening.

Three to five years old


Help your child learn to make decisions by giving them choices when possible.

Let your child start to develop their own sense of who they are.

Teach your child what happens as a result of how they act or choices they make.

Teach "good touch" and "bad touch" near age five.


Take part in programs offered in your community, such as story time at the library.

Let your child learn what they like to do by trying different activities.

Invite families with children your child's age to your home to play.

Cognitive (learning) development

Encourage your child to picture in their mind recent events or things they enjoy.

Help your child to communicate by using letters and colours and by labelling things.

Encourage development through play.

Life skills

Give your child simple errands and simple chores.

Encourage self-care, such as brushing teeth and picking up toys, with reminders or help.

Help your child learn not to do things that will harm themselves or others. For example, teach them not to touch a hot stove, run into the street or hit other people.

PKU care

Take blood spots every two weeks. Set up a routine for doing blood spots at home, so you always do them on the same day and time.

Contact the dietitian or nurse for blood work results.

Tell your child that they have PKU and that you go to clinic to take care of their health.

Identify "green light" or "go" foods. Low-protein foods are best. Encourage your child to drink medical food as prescribed by the dietitian.

Last updated: November 10th 2009