How is Kabuki syndrome diagnosed?

TL;DR: Kabuki syndrome is primarily diagnosed through molecular genetic testing that identifies pathogenic variants in the KMT2D or KDM6A genes. While clinical physical features—such as long palpebral fissures and arched eyebrows—can suggest the diagnosis, confirmation requires genetic verification by a clinical geneticist.

How is Kabuki syndrome diagnosed?

The diagnostic process for Kabuki syndrome typically begins when a pediatrician or specialist notices a constellation of physical features or developmental delays. Because Kabuki syndrome is a multi-system condition, the "diagnostic odyssey" is unfortunately common, often spanning several years before a definitive answer is reached. Diagnosis is confirmed through genetic testing, specifically looking for mutations in the KMT2D gene (associated with approximately 75% of cases) or the KDM6A gene (associated with approximately 5% of cases). In some instances, if these tests are negative, a clinician may order a larger gene panel or whole-exome sequencing to identify rarer genetic causes.

What are the clinical criteria for Kabuki syndrome?

Clinical diagnosis is based on a combination of characteristic physical findings and developmental milestones. While genetic testing is the gold standard, clinicians look for a specific pattern of features to justify testing. Common diagnostic indicators include:

• Facial features: Long palpebral fissures (the opening between the eyelids) with eversion of the lateral third of the lower eyelid, arched eyebrows, and a broad, depressed nasal tip.


• Skeletal anomalies: Specifically brachydactyly (short fingers) or fifth-finger clinodactyly (inward curving).


• Dermatoglyphic abnormalities: Persistent fetal finger pads.


• Growth deficiency: Mild to moderate postnatal growth retardation.


• Intellectual disability: Varying degrees of developmental delay, often accompanied by speech and language difficulties.

Which specialists are involved in the diagnosis?

Because Kabuki syndrome affects multiple body systems, the diagnostic team usually involves a clinical geneticist who coordinates the evaluation. Other specialists often consulted include pediatric neurologists, cardiologists (to check for heart defects), ophthalmologists, and endocrinologists. We recognize that the journey to these specialists can be exhausting and isolating; at DiseaseMaps.org, we have seen 50 individuals navigate this exact path, and we validate the frustration of being passed between departments before reaching a diagnosis. Seeking a geneticist early is crucial, as general practitioners may not be familiar with the rare, subtle phenotypic markers of Kabuki syndrome.

What conditions can mimic Kabuki syndrome?

In the differential diagnosis, clinicians must distinguish Kabuki syndrome from other conditions that present with similar facial features or developmental delays. These include CHARGE syndrome, VACTERL association, 22q11.2 deletion syndrome (DiGeorge syndrome), and various other genetic syndromes involving intellectual disability and skeletal anomalies. Because of this overlap, genetic testing is not just helpful—it is essential to ensure the correct management plan for the patient.

Next steps

• Consult a clinical geneticist: Request a referral to a genetics center that has experience with rare chromatin-modifying disorders.


• Document your journey: Keep a detailed log of developmental milestones, medical records, and photos to share with your specialist.


• Join the community: Connect with the 50 members on DiseaseMaps.org who have experience with Kabuki syndrome to share resources and emotional support.


• Request a multi-disciplinary review: Ask your primary care provider to coordinate a "care team" approach once the diagnosis is suspected.

Medical disclaimer: This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

• NIH GARD: Kabuki Syndrome (https://rarediseases.info.nih.gov/diseases/6817/kabuki-syndrome)


• Orphanet: Kabuki Syndrome (https://www.orpha.net/en/disease/detail/472)


• OMIM: Kabuki Syndrome 1 (https://omim.org/entry/147920)


• Kabuki Syndrome Foundation: Clinical Resources (https://www.kabukisyndromefoundation.org/)