CHARGE syndrome: cause and diagnosis

This page is about the cause of CHARGE syndrome and how the condition is diagnosed.

It covers the main known genetic cause, whether the condition can be inherited, the major and minor features for diagnosis, genetic testing, prenatal diagnosis and genetic counselling.

You’ll also find useful links to more detailed information on some of the symptoms included here.

Sections on this page

What causes CHARGE syndrome?

Changes (mutations) in a particular gene known as CHD7 cause CHARGE syndrome in the majority – more than two-thirds – of people with the condition.

To date, more than 500 different changes to the CHD7 gene have been identified.

Everyone with changes to the CHD7 has some symptoms of CHARGE syndrome.

But, in some people with CHARGE syndrome, no changes in the CHD7 gene can be identified. 

It is possible that some of these people do have a change affecting the CHD7 gene, but it hasn’t been found yet. Other people may have a change in a different gene, but so far no other changed genes causing CHARGE syndrome have been identified.

Environmental factors may also be involved in causing CHARGE syndrome in some people.

Can you inherit CHARGE syndrome?

In almost all cases, no, the condition is not inherited.

The changed CHD7 gene that causes CHARGE syndrome is not passed from a parent to the child. 

The change in the child’s CHD7 gene is known as a de novo (new) change, which means it’s a new change and there is no history of CHARGE syndrome in the family.

Can I pass CHARGE syndrome to my children?

If you are a parent of a child with CHARGE syndrome, and you also have the condition, there is a 50% risk of other children in your family inheriting the condition. 

If neither you nor your partner has CHARGE syndrome, and you have one child with the condition, there is a 1–2% risk of other children in the family also inheriting the condition. 

How is CHARGE syndrome diagnosed?

At one time, someone would be diagnosed as having CHARGE syndrome if they had at least four out of the six features that make up the name CHARGE:

  • Coloboma (an eye condition). 
  • Heart defects.
  • Atresia choanae (choanal atresia; nasal passages blocked by bone or tissue).
  • Retardation (delay) of growth and/or development.
  • Genital abnormalities.
  • Ear abnormalities.

But this is no longer how the condition is diagnosed. 

CHARGE syndrome now has four features known as the major diagnostic criteria, the four C’s:

CHARGE syndrome also has minor diagnostic features, which include:

Someone is diagnosed with CHARGE syndrome if they have:

  • All four C’s.
  • Or three C’s and at least three minor features.

Genetic testing

Genetic testing can confirm a diagnosis of CHARGE syndrome. This involves a DNA test – the substance that contains our genes – for changes to the CDH7 gene.

DNA testing usually involves giving a blood sample or sometimes a skin tissue sample.

Parents of a child with CHARGE syndrome who are considering future pregnancies can both be tested for: 

  • Mild symptoms of CHARGE syndrome.
  • Any changes in their CHD7 gene.

As well as diagnosis, genetic testing can be used to guide counselling, medical management and coordination of services for patients with CHARGE syndrome.

Prenatal diagnosis

During pregnancy, prenatal diagnosis using DNA testing for CHARGE syndrome can be carried out.

But even if DNA testing confirms changes to a child’s CHD7 gene, it cannot be used to predict how mild or severe the child’s symptoms of CHARGE syndrome will be. 

It is always your personal choice whether or not to have prenatal diagnosis. 

Genetic counselling

To arrange a genetic test, ask your GP for a referral to a genetic clinic.

When you ask for a genetic test, your GP might suggest you have genetic counselling. If they don’t, ask them to refer you for genetic counselling.

In genetic counselling, a specially trained professional will give you and your family information on your family member’s specific genetic condition.

This should help you to make the right decisions and understand the impact genetic testing might have on you and your family.

This content was last reviewed in April 2022. We’ll review it again next year.