Congenital hyperinsulinism (CHI)

Hyperinsulinism of infancy (HI)

What is congenital hyperinsulinism?

Congenital hyperinsulinism (CHI) is a rare condition where the pancreas makes too much insulin. Insulin is the hormone that helps control blood sugar levels. When the body produces more insulin than it needs, blood sugar can drop too low, which is known as hypoglycaemia.

As a congenital condition, it is present from birth. Symptoms often appear in babies and young children, although the signs can sometimes be difficult to spot.

CHI can vary from mild to more severe, and each child may be affected differently. Getting treatment quickly with ongoing care and support, will help a child lead a healthy, active life.

What causes congenital hyperinsulinism?

Congenital hyperinsulinism is usually caused by changes in certain genes. These genetic changes make insulin-producing cells more active than they should be, leading to too much insulin.

The most commonly affected genes are ABCC8 and KCNJ11, which help the pancreas regulate when insulin is released. Other genes can also be involved, but they are much rarer.

CHI can be inherited in different ways depending on the gene involved. In some families, more than one child may have CHI, while in others it appears for the first time with no family history. In a small number of babies, no clear cause is found, doctors may call this idiopathic CHI.

What are the symptoms of congenital hyperinsulinism?

The symptoms of CHI happen when blood sugar drops too low, symptoms can include:

  • Sleepiness or low energy – being unusually drowsy or difficult to wake

  • Jitteriness or shaking – small tremors or shivers

  • Poor feeding – feeding slowly, taking small amounts or refusing feeds

  • Irritability or restlessness – crying more than usual or seeming unsettled

  • Pale or clammy skin

  • Low body temperature

  • Seizures – caused by very low blood sugar and needing urgent medical care

  • Developmental changes – if low blood sugar isn’t treated early or happens often

Treating CHI aims to keep blood sugar under control using a combination of medicine, frequent feeding schedules and support from a team of doctors and nurses.

Are you affected by congenital hyperinsulinism (CHI)?

If you’re affected by CHI The Brain Charity can support you.

We are the only charity in the UK to be here for every one of more than 600 different neurological conditions in existence. Individually, many are rare, but combined they affect 1 in 6 people.

We provide practical help on all aspects of living with CHI, emotional support such as counselling, phone befriending and group therapy and social activities to people with CHI from all over the UK from our centre in Liverpool.

Looking to talk to someone?

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Phone us

Contact The Brain Charity now

Our friendly Information & Advice Officers are here to help.

0151 298 2999

Looking to talk to someone?

  • Please tell us which neurological condition you are affected by and what you need support with.

Caring for someone with congenital hyperinsulinism (CHI)

We support carers, friends and family too

Are you a carer or relative of someone with CHI? It’s just as important for you to look after your own physical and mental wellbeing too.

The Brain Charity provides free support for carers, friends and family of people with any form of neurological condition, including CHI, from anywhere in the UK.

We also run additional carers advocacy service for all carers in Liverpool, regardless of which type of condition the person they care for has.

You don’t need to be a formal or registered carer

We can help you even if you don’t view yourself as a formal carer or claim Carer’s Allowance.
Find out some of the ways we support carers below.

Other resources

Support groups

Children's hyperinsulinism UK

A Facebook peer support group for friends and family of those affected by congenital hyperinsulinism.

Support groups at The Brain Charity

Are you interested in setting up a CHI support group or do you already run one?

Email activities@thebraincharity.org.uk to let us know.

Alternatively, you can check out our list of related support groups here.

Other charities

The Children's Hyperinsulinism Charity

Contact: For Families with Disabled Children

Website: www.contact.org.uk

Phone: 0808 808 3555

Email: fill out the enquiry form for Contact’s helpline team