What is CHARGE?
CHARGE Syndrome, also known as CHARGE association, is thought to occur around the third week of fetal development. (deKort 2003) Tissue in various structures of the body do not complete in development. Major organs such as the heart and kidneys are affected, and these early critical medical issues keep children in hospital for extended periods. Children undergo extensive medical proceedures, such as the repair for choanal atresia. But as well, sensory systems are affected, leaving children with reduced vision, hearing, and vestibular abilities. Cranial nerve involvement means these children often have problems in sucking, swallowing, usually have reflux and future problems in feeding remain.
In 2004 a Netherlands study (Vissers, LELM, et.al) found a gene (CHD7 on 8Q12) which was implicated in 2/3 of those tested. This gene is responsible for encoding a number of DNA protein which is esential when neural crest cells are being formed and migrating. A negative genetic test for changes in the CHD7 gene can still result in a diagnosis of CHARGE.
Not all individuals with CHARGE syndrome will have the same clinical features, and each of the clinical features can vary in their degree of severity. This makes diagnosis very difficult and so individuals should be seen by a geneticist who is familiar with CHARGE syndrome.
Key major clinical features include coloboma or incomplete development of various structures of the eye, choanal atresia, semicircular canal anomolies (Verloes, 2005), the characteristic CHARGE ear, and cranial nerve anomolies (Blake KD; Prasad, C 2004) There are many minor clinical features which could occur in CHARGE syndrome. These could include: genital hypoplasia, cardiovascular malformations, growth deficiency, orofacial cleft, tracheoesophageal fistula, and the distinctive CHARGE face. (Blake, Prasad, C 2004)
Blake, KD; Prasad, C. CHARGE Syndrome (2004) available on the World Wide Web at:
www.orpha.net/static/GB/CHARGEassociation.html (2004; Blake, KD; Prasad, C.)
Blake, KD; Davenport LLH; Hall BD; Hefner M; Pagnon RA; Williams MS; Graham JM. CHARGE Association - An update and review for the primary Pediatrician. Clinical Pediatrics, 1998; 37 (3): 159-173.
deKort, Dr. Arno and Dr. Jan Van Dyke, 2003. Keynote address, 6th International CHARGE Sydnrome Conference, Ohio.
Vissers, LELM, et al; Mutations in a new chromodonain gene family cause CHARGE syndrome. Nature Genetics online. (8/8/04)
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