CHARGE Syndrome Definition
CHARGE Syndrome is a congenital set of symptoms in children resulting due to a genetic disorder. It is in fact an acronym for the following characteristics seen in the affected children:
C – Coloboma of eye
H – Heart problems
A – Atresia of choanae
R – Retardation of development or growth
G – Genital disorders
E – Ear disorders
CHARGE syndrome is also less commonly known as Hall-Hittner syndrome. It is an autosomal dominant genetic disorder that usually develops due to Chromodomain helicase DNA-binding protein-7 (CHD7) gene’s mutations.
CHARGE Syndrome Life Expectancy
70% of the children diagnosed with various CHARGE syndrome features have been found to reach the minimum age of 5 years. Among the remaining 30%, highest numbers of deaths have been recorded in the first year itself.
A combination of bilateral posterior choral atresia, congenital tracheo-esophageal and heart defects is the most fatal form of CHARGE. Even the presence of any of the latter two in combination with atresia of choanae has high mortality rate. CNS atresia too leads to poor survival records of children suffering with CHARGE syndrome.
Death rates following an operation are also relatively high in case of CHARGE syndrome. This happens due to the unseen abnormalities of structure of the pharynx or larynx with related motor incoordination. As a result of this, intubation gets difficult and problems surface after extubation.
CHARGE Syndrome Symptoms
The symptoms of CHARGE syndrome are not the same in each child. These vary in severity too. Most of the characteristics of CHARGE syndrome are not specific to only this syndrome and are usually seen in children without CHARGE syndrome too. The commonly noticed CHARGE syndrome symptoms are as follows:
- Coloboma of eye is seen in 80-90% of the individuals diagnosed with CHARGE syndrome. One or sometimes both eyes may be missing or too small.
- Cranial nerve abnormality which leads to decrease in the smelling sense, facial paralysis or difficulty in swallowing.
- Growth retardation due to the deficiency of growth hormone or difficulty in feeding. This is usually seen in the first six months. However, the growth catches up after a certain period.
- Choanal atresia is observed in 35-65% of infants with CHARGE syndrome. This is observed when the rear part of the nasal sinuses is narrowed and fails to link with the back of throat.
- Ear abnormalities like malformation on the outside and abnormal nerve and semicircular canals defects are noticed in majority of the cases. This also leads to deafness depending on the severity.
- Various types of heart disorders are noticed. Of these, a hole in the heart is the most commonly observed one.
- The genitals too are underdeveloped compared to a normal infant.
- Mental retardation is notice as the IQ ranges between normal and severe retardation.
- Other less significant features of CHARGE syndrome are different kidney abnormalities like reflux, small kidney, and missing or misplaced kidney.
- Cleft lip with/without cleft palate, sub-mucous cleft palate and cleft palate.
CHARGE Syndrome Causes
CHARGE syndrome is a genetic disorder occurring due to mutations of a single gene. The gene that undergoes this abnormal change is usually CHD7 present on the chromosome #8’s long arm. CHD7 is in fact a regulatory gene playing an important role in turning the other genes on & off. More than half of the children reported with CHARGE syndrome when tested revealed changes in CHD7.
In majority of the cases, the parents of the affected child were not found to be suffering with CHARGE syndrome. The change of gene was new in the infant. This shows that CHARGE syndrome is in fact a genetic disorder which occurs as a result of new change in a dominant gene.
Research is being done to find if other genes too are responsible for CHARGE and also to find the functioning of these genes in adults, babies, children and developing fetus.
CHARGE Syndrome Pictures
Picture 1 : Children with CHARGE syndrome photos
Image source : chargesyndrome.org
Picture 2 : Ear disorders in CHARGE syndrome
Image source : eutils.wip.ncbi.nlm.nih.gov
Picture 3 : Phenotypic spectrum of CHARGE syndrome with CHD7 truncating mutations.
Image source : jmg.bmj.com and Journal of medical genetics
CHARGE Syndrome Diagnosis
The diagnosis of CHARGE syndrome depends on the physical signs or symptoms of the child. Usually, the important signs to look out for are abnormal semicircular ear canals, choanal atresia, abnormal appearance of ears and coloboma. Heart defects occur is various other syndromes or disorders and therefore cannot be of much help in confirming the diagnosis of CHARGE syndrome.
Some other diagnostic tests that are usually recommended in a suspected case of CHARGE syndrome include:
- Genetic tests like Karyotype that confirms the reliability of chromosome numbers 9, 14 and 22. CHD7 gene mutation testing is also available in most clinics now. For patients with normal CHD7 mutation investigation results are considered for a comparative genomic hybridization.
- Biochemical tests involving testing of blood urea nitrogen, electrolytes, calcium, T-cells and creatinine.
- Hearing tests for analyzing auditory brainstem and audiometric response and the severity of sensorineural and conductive hearing loss.
- Cardiac investigations such as echocardiogram and Holter monitoring.
- Hormonal tests such as Human Chorionic Gonadotropin and Luteinising Hormone Releasing Hormone tests.
- Vision analysis, functional vision testing and electro-retinogram for identifying visual loss’ severity.
- Various other radiological tests including CT, MRI scans, DEXA scan, cystourethrogram and abdominal ultrasound.
CHARGE Syndrome Prognosis
Various records reveal that almost half of the patients suffering from CHARGE syndrome don’t live longer due to the complications of the disorder. The various factors affecting the survival chances include the diagnosis of bilateral choanal atresia, TE fistula and CNS malformations. The conditions unrelated to poor prognosis include brainstem dysfunctions and heart problems. However, proper medical care and hospitalization are recommended for most patients.
CHARGE Syndrome Treatment
The CHARGE syndrome treatment and management depends on the features noticed in each affected child. A choanal atresia condition is usually treated with nasal or choanoa passages’ dilatations. Heart abnormalities usually require a surgery. For the affected child, ophthalmology and hearing tests should be carried out at least twice an year. For any corrections of facial asymmetry or ear malformations, a plastic surgery is recommended.
Medications are usually given if seizures are experienced. For growth delay/retardation and underdeveloped genitalia, various growth hormones are recommended based on the condition.
CHARGE Syndrome Foundation
The CHARGE Syndrome Foundation established in the year 1993 is a non-profit charitable organization that works for helping the CHARGE syndrome patients and their families. Operating from New York, this foundation consists of 12 Board members of which 7 of them or any of their family members are supposed to be affected with CHARGE syndrome.
The CHARGE syndrome foundation not only provides information but also supports and helps more than 400 members, the patients and the families of an affected child.
The foundation contacts medical practitioners and professionals worldwide to provide support in research and treatment of CHARGE syndrome. The organization also publishes a newsletter and manual for the families. It also provides resources to the families and the professionals helping the children with CHARGE syndrome.
Mendelian Inheritance in Man: A Catalog of Human Genes and Genetic Disorders – McKusick, Victor, The Johns Hopkins University Press.