In 1998, an expert group defined the major (the classical 4C´s: Choanal atresia, Coloboma, Characteristic ear and Cranial nerve anomalies) and minor criteria of CHARGE syndrome [1]. In 2004, mutations in the CHD7 gene were identified as the major cause. The inheritance pattern is autosomal dominant with variable expressivity. Almost all mutations occurs de novo, but parent-to-child transmission has occasionally been reported [2].

Clinical criteria for CHARGE syndrome [1]

Major criteria:

• Coloboma
• Choanal Atresia
• Cranial nerve anomalies
• Abnormalities of the inner, middle, or external ear

Minor criteria:

• Cardiaovascular malformations
• Genital hypoplasia or delayed pubertal development
• Cleft lip and/or palate
• Tracheoesophageal defects
• Distinctive CHARGE facies
• Growth retardation
• Developmental delay

Occasional:

• Renal anomalies: duplex system, vesicoureteric reflux
• Spinal anomalies: scoliosis, osteoporosis
• Hand anomalies
• Neck/shoulder anomalies
• Immune system disorders

Individuals with all four major characteristics or three major and three minor characteristics are highly likely to have CHARGE syndrome [1].

CHARGE syndrome occurs in approximately 1 in 10000 newborns [3]. In more than 90% of patients fulfilling the clinical criteria for CHARGE syndrome mutations in the CHD7 gene in chromosome 8q12 can be detected [4].