Introduction

CHARGE syndrome is a rare but complex condition that affects many parts of a child’s body. It can cause problems with vision, hearing, heart, breathing, and growth. Each child with CHARGE syndrome is different, and this can make it hard to recognise and diagnose early on.¹

Doctors first used the word “CHARGE” as an acronym to help remember the most common signs of the condition, like coloboma, heart defects, and problems with the nose, ears and development. We know that changes in a gene called CHD7 are often involved. This has helped doctors confirm more cases through genetic testing.

Despite these advances, challenges remain. Some children do not show all the “classic” signs. Others may not have a CHD7 gene change at all. This makes diagnosis unpredictable and sometimes delayed, especially in places where access to specialists or testing is limited.

This article looks at how the diagnostic criteria for CHARGE syndrome have changed over time, the role of genetic testing, and why a clear and early diagnosis still matters so much.

Historical context and evolution of diagnostic criteria

CHARGE syndrome was first described in the late 1970s, when doctors noticed a group of children who had similar patterns of birth defects. The acronym “CHARGE” was created as a helpful way to remember the most common characteristics: coloboma (a defect or gap in the eye), heart defects, atresia of the choanae (obstruction of the nasal passages), developmental difficulties, abnormalities in the genitals, and ear irregularities. These became the basis of the early clinical diagnosis.²

At the time, diagnosis was based mostly on observing physical signs. However, not all children had all six features, and many had other problems that were not included in the acronym. This made diagnosis inconsistent and sometimes uncertain.³

A breakthrough came when scientists discovered that mutations in the CHD7 gene were responsible for many cases of CHARGE syndrome. This opened the door to genetic testing, which has helped confirm the diagnosis in many children, even those with milder or less typical symptoms.

Over time, the approach to diagnosis has shifted from relying solely on physical signs to combining clinical features with genetic findings. Many cases still fall into a “grey area,” where not all signs are present, or where genetic testing does not show a clear result.⁴

Diagnostic criteria

Diagnostic framework

CHARGE syndrome is usually diagnosed using a mix of clinical features and genetic testing. One of the most widely used sets of criteria groups the signs of CHARGE into major and minor features.^5,6

Major features (more specific to CHARGE):

• Coloboma: a hole or gap in part of the eye, which can affect vision
• Choanal atresia: blocked or narrow nasal passages, making it hard to breathe through the nose
• Hypoplastic semicircular canals: underdeveloped inner ear structures that affect balance and hearing 

Minor features (common but less specific):

• Heart defects
• Genital abnormalities
• Growth and development delays
• Cleft lip or palate
• Abnormal outer ears or hearing loss

To be diagnosed using these criteria, a child typically needs at least two major features and several minor features. However, if all three major features are present, a diagnosis is likely even if some minor features are missing. 

One of the biggest breakthroughs in understanding CHARGE syndrome came with the discovery of the CHD7 gene. Researchers found that changes (mutations) in this gene are responsible for most cases of CHARGE. Since then, genetic testing has become an important diagnostic tool.

Changes in the CHD7 gene are found in about 60–90% of people who meet the clinical signs of CHARGE. It is essential to note that not all individuals with CHARGE syndrome have a CHD7 mutation, and not everyone with a CHD7 mutation exhibits the classic signs. That is why the diagnosis remains a clinical one first, supported by genetic findings.

Doctors now take a combined approach using detailed physical exams, brain and ear imaging (like MRI), hearing tests, and genetic screening to make the diagnosis as accurate and early as possible.^4,7

Challenges in diagnosis

Even with better testing and clearer guidelines, diagnosing CHARGE syndrome is still not always easy. There are a few key reasons why this remains a challenge.

One of the main challenges is that no two people with CHARGE are exactly alike. The condition can affect many parts of the body, but not everyone shows the same signs or to the same degree. Some children might have several of the key features, such as vision problems or blocked nasal passages, while others may only show more subtle signs like hearing loss or developmental delay. This variation in symptoms is called phenotypic variability.^5,8

Another challenge is that many features of CHARGE syndrome are also present in other genetic or developmental disorders. For instance, conditions such as DiGeorge syndrome, Kabuki syndrome, or VACTERL syndrome can cause cardiac issues, growth challenges, and facial anomalies. Due to this overlap, children with CHARGE may be incorrectly diagnosed or missed entirely, particularly if they do not exhibit the more typical features.⁴

There are also cases where a child does not meet all the official diagnostic criteria. These “atypical” presentations might include only one major feature or a few minor ones, and sometimes genetic testing does not reveal a CHD7 mutation.⁶ 

Access to genetic testing is another barrier. While genetic tests are becoming more available, they can still be expensive or limited to certain places or regions. In such cases, families may wait years for a formal diagnosis or never receive one at all, making it harder to plan for care, support, or future pregnancies.¹⁰

Multidisciplinary implications of diagnosis

CHARGE syndrome affects many parts of the body, so care usually involves a team of specialists. Early diagnosis helps connect families with the right support, like hearing aids, feeding therapy, or surgery for heart defects. ENT specialists, cardiologists, geneticists, and developmental therapists often work together to create a care plan. This team approach can improve a child’s quality of life and development. A clear diagnosis also helps parents understand what to expect and make informed decisions. Without proper coordination, important issues may be missed or treated too late.^2,5

Future directions and recommendations

As our understanding of CHARGE syndrome grows, there is a push for more flexible and inclusive diagnostic tools. Many experts support a combined model that looks at both clinical features and genetic results together, rather than relying on one or the other. 

More global databases and patient registries are also helping researchers spot new patterns and expand the definition of the syndrome. Future guidelines may better include people with mild or unusual symptoms, even if they do not have a CHD7 mutation.⁷

Summary

CHARGE syndrome is a rare condition affecting many body systems, leading to issues with vision, hearing, heart, breathing, and growth. Diagnosing this syndrome can be challenging because each child shows different signs, and some may not display all the classic features. The term “CHARGE” stands for key characteristics such as coloboma, heart defects, and developmental issues. Changes in the CHD7 gene are linked to many CHARGE cases, aiding in diagnosis through genetic testing. However, not every child with CHARGE has a CHD7 mutation, complicating diagnosis. The diagnosis has evolved since the 1970s, shifting from observation of physical traits to combining these observations with genetic findings.

Typically, a child needs two major features and several minor ones to receive a diagnosis. Though advancements have been made, diagnosing CHARGE remains difficult due to individual variations in symptoms and the overlap with other disorders. Some children may not meet all diagnostic criteria or may lack a detectable CHD7 mutation, leading to misdiagnosis. Early and precise diagnosis helps connect families with the necessary support and care from various specialists. Moving forward, experts urge for more inclusive diagnostic methods that consider varying clinical features and genetic results, alongside creating global databases to enhance understanding of the syndrome.