CHARGE syndrome

Definition

The term CHARGE is an acronym in which each letter represents one of the symptoms typical of the syndrome. C stands for "Coloboma", referring to an ocular congenital malformation, a slit defect in one of the eye's structures, and, just like the other congenital malformation present in cases of CHARGE syndrome, occurs during the early foetal stages. H stands for "Heart defect", which is to say a congenital malformation of the heart. A stands for "Atresia of the choanae", i.e. narrow posterior nasal openings. R stands for "Retardation of growth and/or development", meaning stunted growth and/or intellectual disability. G stands for "Genital defects" and refers to the presence of underdeveloped genitals. E stands for "Ear anomalies and/or deafness", i.e. congenital ear malformations and/or hearing impairment/deafness.

Other common symptoms include cleft lip, jaw, and/or palate, impact on cranial nerves and congenital malformation of the urinary tract or kidneys. Children with CHARGE syndrome may also be born with a gateway directly connecting the trachea and oesophagus (tracheoesophageal duct).

Several cranial nerves can be affected and cause weakening of facial muscles, impaired palatal function and difficulties with swallowing. Sense of smell may be impaired. In order to meet criteria for CHARGE syndrome, a certain number of the symptoms described must be present.

Prevalence has been estimated at approximately one in 10,000 live births.

Causes

CHARGE syndrome is usually caused by changes (mutations) in a gene called CHD7, located on chromosome 8. Throughout the foetal period this gene controls the formation of a protein that impacts a number of organ systems. CHARGE syndrome usually occurs as a de novo mutation, meaning that the condition has not been inherited from either of the parents. CHARGE syndrome can also be inherited, in which case autosomal dominant heredity applies.

Examination and treatment

Children with CHARGE syndrome often need very comprehensive help from specialists with different types of assessments, surgeries and frequent follow-up from healthcare and habilitation services.

The assessment includes mapping out different organ systems and how the congenital malformation in question affects level of function, as well as making decisions regarding what measures to take and which treatment to administer. Assessment and follow-up also include evaluating different areas of function, such as sight, hearing, motor control/balance, capacity for abstract thinking, language-related and other communicative ability, capacity for social interaction, and behaviour.

Symptomatic presentation

The symptomatic presentation in cases of CHARGE syndrome varies greatly and for some children entails major medical effects; heart defects, airway problems, difficulties with eating/swallowing, visual impairment and hearing impairment. Some cases may also present with different cognitive and motor control-related function problems, for example mental retardation, autism and motor dysfunction. There are, however, children with CHARGE syndrome presenting with less severe symptoms and who suffer less of an effect to their ability to function in different aspects.