CHARGE syndrome

Epidemiology and Etiology:

· Autosomal dominant

Common sites:

·

Gross features:

· Coloboma (80-90%)

· Unilateral or bilateral

· Iris, retina-choroid, and/or disc

· micro-ophthalmos maybe

· Heart defects (75-85%)

· choanal Atresia (50-60%)

· unilateral or bilateral

· atresia or stenosis

· Retarded growth and development

· Growth retardation (70-80%)

· Genital abnormalities

· Cryptorchidism in males

· Hypogonadotrophic hypogonadism

· Ear anomalies

· Abnormal outer ears (cupped)

· Ossicular malformations

· Mondini defect of the cochlea

· Absent or hypoplastic semicircular canals

· Others:

· Cranial nerve dysfunction (70-90%)

· Hyposomia or anosmia

· Unilateral or bilateral facial palsy (40%)

· Impaired hearing

· Swallowing problems

· Orofacial clefts (15-20%)

· Tracheoesophageal fistula (15-20%)

·

Histologic features:

·

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

· CHD7 mutation (60-65%) (8q12.1)

· only gene known to be associated with CHARGE syndrome

· Chromodomain helicase DNA binding protein

· important role in regulating early embryonic development and cell cycle control by affecting chromatin structure and gene expression

Other features:

· Neonates have multiple life-threatening medical conditions often

· Feeding difficulties major cause of morbidity

· Radiology

· Temporal bone imaging is helpful in diagnosis

References:

· GeneReviews (2009)