How is Chediak Higashi Syndrome diagnosed?

Chediak Higashi Syndrome is diagnosed primarily through the identification of giant peroxidase-positive inclusion bodies in white blood cells and confirmed via genetic testing for mutations in the LYST gene. Because this is an extremely rare, multi-system disorder, clinicians look for a combination of oculocutaneous albinism, recurrent infections, and neurological symptoms to trigger further investigation.

How is Chediak Higashi Syndrome diagnosed?

The diagnostic journey for Chediak Higashi Syndrome often begins with a peripheral blood smear. A pathologist looks for pathognomonic "giant granules" within neutrophils and other leukocytes. Because these markers are highly specific, they serve as the primary clinical indicator. Following this, clinicians must confirm the diagnosis through molecular genetic testing to identify biallelic pathogenic variants in the LYST gene, which is the gold standard for confirming Chediak Higashi Syndrome.

What tests and examinations are involved?

The diagnostic evaluation is comprehensive and typically involves the following:

• Peripheral Blood Smear: Microscopic examination to detect the characteristic giant, peroxidase-positive inclusions.


• Molecular Genetic Testing: Sequencing of the LYST gene to confirm the clinical suspicion.


• Bone Marrow Examination: Often performed to rule out hemophagocytic lymphohistiocytosis (HLH), a life-threatening complication of Chediak Higashi Syndrome.


• Ophthalmologic Exam: To assess for nystagmus and retinal pigmentation changes associated with the condition.

Which specialists manage the diagnostic process?

Due to the complexity of Chediak Higashi Syndrome, diagnosis is usually coordinated by a pediatric immunologist or a hematologist-oncologist. Genetic counselors are also essential to help families understand the autosomal recessive inheritance pattern. We recognize that the "diagnostic odyssey" for Chediak Higashi Syndrome can be incredibly isolating; please know that your experience is valid, and seeking care at a major academic medical center or a center specializing in primary immunodeficiencies is critical if your local providers are unfamiliar with this rare presentation.

What conditions are confused with this syndrome?

Clinicians must differentiate Chediak Higashi Syndrome from other forms of oculocutaneous albinism and other primary immunodeficiency syndromes, such as Griscelli syndrome or Hermansky-Pudlak syndrome, which also feature pigmentary dilution and immune dysfunction.

Next steps

• Consult with a board-certified clinical immunologist or hematologist.


• Request a referral to a geneticist for LYST gene testing.


• Connect with the 3 members in our DiseaseMaps community who share this diagnosis for peer support.


• Keep a detailed log of all recurrent infections and developmental milestones to assist your medical team.

Medical disclaimer: This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of a qualified healthcare provider.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Chediak-Higashi Syndrome


• Orphanet: Chediak-Higashi Syndrome (ORPHA:167)


• OMIM (Online Mendelian Inheritance in Man): #214500


• Immune Deficiency Foundation (IDF)