CHD7 Disorder-Not CHARGE Syndrome-Presenting as Isolated Cochleovestibular Dysfunction

Area of Science:

• Genetics
• Otolaryngology
• Developmental Biology

Background:

• CHARGE syndrome is historically defined by specific clinical features and linked to CHD7 gene mutations.
• The diagnostic spectrum of CHD7-related disorders has expanded beyond CHARGE syndrome.
• CHD7 variants are increasingly recognized in individuals with isolated features like autism or hormonal deficiencies.

Observation:

• This study details three cases from two families where audiovestibular impairment was the primary symptom of a CHD7 variant.
• These cases demonstrate significant phenotypic variability associated with CHD7 mutations.
• Audiovestibular impairment, particularly when accompanied by inner ear malformations on MRI, should prompt consideration of CHD7 variants.

Findings:

• CHD7 variants can manifest primarily as hearing loss and balance issues, expanding the known phenotype.
• The study underscores the wide range of clinical presentations for CHD7 disorders.
• Genetic analysis of CHD7 is crucial for diagnosing individuals with unexplained audiovestibular deficits.

Implications:

• The findings necessitate broadening the differential diagnosis for nonsyndromic hearing loss to include CHD7 variants.
• Genetic counseling and thorough clinical evaluation are vital for managing the diverse health concerns in individuals with CHD7 variants.
• This research contributes to a more comprehensive understanding of CHD7-related disorders and their genetic basis.