CHARGE Syndrome
CHARGE Syndrome is a complex constellation of anomalies including Coloboma of the eye, Heart defects, choanal Atresia, Retardation of growth and/or development, Genital abnormalities, and Ear abnormalities.
PrintCHARGE Syndrome is a complex constellation of anomalies including Coloboma of the eye, Heart defects, choanal Atresia, Retardation of growth and/or development, Genital abnormalities, and Ear abnormalities.
Genetic testing is useful to confirm the diagnosis and to distinguish CHARGE Syndrome from other conditions such as VACTERL association and 22q11.2 deletion syndrome.
Mutations in the CHD7 gene account for approximately 58-65% of individuals affected with CHARGE Syndrome. The Ambry Test: CHARGE Syndrome consists of gene sequence analysis of CHD7, capable of detecting >96% of described mutations in this gene.
CHARGE syndrome is a complex constellation of multiple congenital anomalies, characterized by Coloboma of the eye, Heart defects, choanal Atresia, Retardation of growth and/or development, Genital abnormalities, and Ear abnormalities.1 The most common features of this condition include structural malformations of the outer ear, as well as inner and/ or middle ear abnormalities that result in hearing loss, seen in 90-100% of affected individuals.3 Coloboma of the iris, retina, or choroid is present in 80-90% of cases.7 Choanal atresia or choanal stenosis can be bilateral or unilateral. Affected individuals can also have swallowing difficulties, facial palsy, hyposmia or anosmia. Other features can include complex heart defects, genital hypoplasia, short stature, tracheoesophageal fistula, and cleft lip and/or palate.2,3
The majority of CHARGE syndrome cases are caused by mutations in the CHD7 gene. Defects in this gene affect early embryonic development and cell cycle control. Most mutations within this gene result in a truncated protein, leading to haploinsufficiency in affected individuals.4 Many CHARGE Syndrome cases are the result of a de novo mutation, but a small number of cases have been inherited in an autosomal dominant manner.1 Mutations in the CHD7 gene are 100% penetrant and account for approximately 58-65% of individuals affected with CHARGE syndrome.1,4,5 It is estimated that this syndrome occurs in 1 in 8,500 live births and affects all ethnic backgrounds worldwide.
Children with CHARGE syndrome require intensive medical management and surgical treatment. Early intervention helps improve the quality of life of an affected individual. Genetic testing is an especially useful tool to identify individuals suspected of having CHARGE syndrome as it can help distinguish this syndrome from other conditions such as VACTERL association and 22q11.2 deletion syndrome. Prenatal diagnosis may be considered in families with a previous history of CHARGE syndrome.
This Ambry Test is a gene sequence analysis of CHD7 performed by PCR-based double-stranded automated sequencing in the sense and antisense directions for exons 2-38 of the CHD7 gene, plus at least 20 bases into the 5’ and 3’ ends of all the introns. Specific mutation analysis for familial CHD7 mutations is also available.
Mutations in the CHD7 gene account for approximately 58-65% of individuals affected with CHARGE syndrome.1,4,5 The Ambry Test: CHARGE Syndrome is capable of detecting >96% of described mutations in CHD7.
Blood: Collect 3-5 cc from adult or 2 cc minimum from child into EDTA purple-top tube (first choice) or ACD yellow-top tube (second choice). Store at room temperature or refrigerate. Ship at room temperature.
Blood Spot: Call for availability.
Saliva: Collect 2 ml into Oragene™ DNA Self-Collection container. Store and ship at room temperature.
DNA: Send 20 μg in TE at 50-100 ng/μl. Store frozen and ship on ice or dry ice.
Prenatal: Prenatal testing is available. Please call an Ambry Genetic Counselor to discuss your case.
| Test Code | Technique | CPT Codes |
|---|---|---|
| 2380 | CHD7 Gene Sequence Analysis | 83891x1, 83894x39, 83898x38, 83904x60, 83909x45, 83912x1 |
| Technique | Days |
|---|---|
| CHD7 Gene Sequence Analysis | 10-21 |
1 Jongmans MCJ et al. J Med Genet. 2006; 43: 306-314.
2 Verloes A. Amer J Med Genet. 2005; 133A: 306-308.
3 Blake K & Prasad C. Orph J Rare Diseases. 2006; 1(34):1-8.
4 Sanlaville et al. Europ J of Hum Geneti. 2007; 15: 389-399.
5 Lalani SR et al. Amer J Hum Genet. 2006; 78: 303-314.
6 Issekutz KA et al. Amer J Med Genet. 2005; 133A: 309-317.