====== CHARGE Syndrome ======

===== Characteristics =====

  * **C**oloboma
    * Unilateral or bilateral coloboma of the iris, retina-choroid, and/or disc with or without microphthalmos (80%-90% of individuals)
  * **H**eart Defects (75-85%)
    * Almost every type of congenital heart defect has been described including VSD, ASD, PDA
    * Many have multiple and complex defects: aortic arch defects, shunts, AV canal and others. Cardiology of CHARGE
  * **A**tresia of the choanae
    * Unilateral or bilateral choanal atresia or stenosis (50%-60%)
  * **R**etarded growth and development
    * Growth deficiency (70%-80%)
    * Developmental Delay
  * **G**enital abnormalities
    * Cryptorchidism in males and hypogonadotrophic hypogonadism in both males and females
  * **E**ar anomalies
    * Abnormal outer ears, ossicular malformations, Mondini defect of the cochlea and absent or hypoplastic semicircular canals (>90%)
    * impaired hearing and/or swallowing problems (70-80%)
  * **Other problems**
    * Cranial nerve dysfunction resulting in hyposmia or anosmia, unilateral or bilateral facial palsy (40%), swollowing problems (70-90%)
    * Orofacial clefts (15%-20%)
    * Tracheoesophageal fistula (15%-20%)

==== Major Characteristics: More specific for CHARGE ====

  * Ocular Coloboma
  * Choanal atresia or stenosis
  * Hearing loss
  * Cranial nerve abnormalities

==== Minor Characteristics: Less specific for CHARGE, more important if many of these present ====

  * Heart Defects
  * Growth and Developmental Delay
  * Cleft Lip and or Palate
  * Genital abnormalities
  * Tracheoesophageal fistula

===== Incidence =====

  * Estimated to occur in 1:8,500 to 1:10,000 people

===== Genetics =====

  * Inheritance Pattern 
    * Autosomal Dominant, most with new mutation
  * Genes
    * CHD7 found to cause more than 50% of cases
    * CHD7 gene product regulates gene expression by chromatin remodeling.
    * CHD7 mutations can have varied and widespread effects during embryonic development

===== Ocular Considerations =====

  * Retinal Detachment Risk: 8% in a study by Keech and others-1997
  * Vision may be affected or not depending upon the position and extent of the coloboma
  * Trial of ambylopia treatment may be warranted
  * Cataract may accompany coloboma

===== Resources =====
[[http://ghr.nlm.nih.gov/condition/charge-syndrome|NLM Genetics Home Reference]]\\
[[http://www.ncbi.nlm.nih.gov/books/NBK1117/|GeneReviews]]\\
[[http://www.ncbi.nlm.nih.gov/sites/GeneTests/lab/clinical_disease_id/83233|GeneTests Labs for Gene Testing]]\\
[[http://chargesyndrome.org/manual/Heart.pdf|Cardiology of CHARGE]]

{{tag>syndrome}}