CHARGE syndrome is a multisystem congenital developmental defect that is named as a mnemonic for its five most prominent clinical features: Coloboma, Heart defect, Choanal atresia, Retardation of growth, Genital hypoplasia and Ear malformations. Although these are the major symptoms of the condition, none of these features is universally present in all affected cases. Other minor features of the condition include facial paralysis, typical facial features including square shaped head, flat cheekbones, and wide nose, difficulties in swallowing, cleft palate, esophageal atresia, tracheo-esophageal fistula, malformations of the urinary tract, and CNS disorders. The pathophysiology of the condition arises from a developmental defect involving the midline structures of the body, specially affecting the craniofacial structures. This effect in itself arises from an arrest in differentiation during the second month of embryonal development. It is estimated that 1 in every 8,500 to 12,000 neonates is affected with CHARGE Syndrome.
CHARGE Syndrome is inherited in an autosomal dominant fashion. The underlying genetic defect, however, is heterogeneous. In most cases, the defect is a mutation in the CHD7 (Chromodomain Helicase 7) gene. The protein product of this gene is most probably a transcription regulator, although it is not clear what its exact function during embryological development is, or how mutations could affect development. A minor category of patients with CHARGE syndrome show other genetic defects, for instance, cytogenetic abnormalities, such as 22q11.2 deletion, and mutations in the Semaphorin 3E gene.
Petkovska et al. (2007) carried out a retrospective analysis of children identified with congenital choanal atresia over a period of three years (2001-2004). Of the seven children thus identified, two were found to have clinical conditions fitting the criteria for CHARGE syndrome.
Sawardekar (2005) conducted a study to establish the prevalence of major congenital malformations in children born during a 10-year period in Nizwa Hospital. Of the 21,988 total births in the hospital, two children were born with CHARGE Syndrome.
Ben Becher et al. (1994) reported the case of a 4 1/2 month-old boy who suffered from microphthalmia. His weight was 6 kg (-1 SD), height 60 cm (-2 SD) and his head circumference was 44 cm (+ 2 SD). He had hypotonia. Examination showed low-set ears, micrognathia, coloboma, left choanal atresia and genital hypoplasia. His heart was normal.