CHARGE syndrome (formerly known as CHARGE association) is a rare
syndrome
A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek σύνδρομον, meaning "concurrence". When a syndrome is paired ...
caused by a
genetic disorder
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders ...
. First described in 1979, the
acronym
An acronym is a word or name formed from the initial components of a longer name or phrase. Acronyms are usually formed from the initial letters of words, as in ''NATO'' (''North Atlantic Treaty Organization''), but sometimes use syllables, as ...
"CHARGE" came into use for newborn children with the congenital features of
coloboma of the eye,
heart defects,
atresia of the nasal choanae,
retardation of growth and/or development,
genital and/or urinary abnormalities, and ear abnormalities and
deafness
Deafness has varying definitions in cultural and medical contexts. In medical contexts, the meaning of deafness is hearing loss that precludes a person from understanding spoken language, an audiological condition. In this context it is written ...
.
These features are no longer used in making a diagnosis of CHARGE syndrome, but the name remains. About two thirds of cases are due to a
CHD7
Chromodomain-helicase-DNA-binding protein 7 also known as ATP-dependent helicase CHD7 is an enzyme that in humans is encoded by the ''CHD7'' gene.
CHD7 is an ATP-dependent chromatin remodeler homologous to the Drosophila trithorax-group protei ...
mutation. CHARGE syndrome occurs only in 0.1–1.2 per 10,000 live births; as of 2009, it was the leading cause of congenital
deafblindness
Deafblindness is the condition of little or no useful hearing and little or no useful sight. Different degrees of vision loss and auditory loss occur within each individual. Because of this inherent diversity, each deafblind individual's needs re ...
in the US.
Genetics
CHARGE syndrome was formerly referred to as CHARGE association, which indicates a non-random pattern of congenital anomalies that occurs together more frequently than one would expect on the basis of chance. Very few people with CHARGE will have 100% of its known features. In 2004, mutations on the
CHD7
Chromodomain-helicase-DNA-binding protein 7 also known as ATP-dependent helicase CHD7 is an enzyme that in humans is encoded by the ''CHD7'' gene.
CHD7 is an ATP-dependent chromatin remodeler homologous to the Drosophila trithorax-group protei ...
gene (located on
Chromosome 8
Chromosome 8 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 8 spans about 145 million base pairs (the building material of DNA) and represents between 4.5 and 5.0% of the total DNA ...
) were found in 10 of 17 patients in the Netherlands, making CHARGE an official syndrome. A 2006 US study of 110 individuals with CHARGE syndrome showed that 60% of those tested had a mutation of the CHD7 gene.
In 2010, a review of 379 clinically diagnosed cases of CHARGE syndrome, in which
CHD7
Chromodomain-helicase-DNA-binding protein 7 also known as ATP-dependent helicase CHD7 is an enzyme that in humans is encoded by the ''CHD7'' gene.
CHD7 is an ATP-dependent chromatin remodeler homologous to the Drosophila trithorax-group protei ...
mutation testing was undertaken found that 67% of cases were due to a
CHD7
Chromodomain-helicase-DNA-binding protein 7 also known as ATP-dependent helicase CHD7 is an enzyme that in humans is encoded by the ''CHD7'' gene.
CHD7 is an ATP-dependent chromatin remodeler homologous to the Drosophila trithorax-group protei ...
mutation.
CHD7 is a member of the chromodomain helicase DNA-binding (CHD) protein family that plays a role in transcription regulation by
chromatin remodeling
Chromatin remodeling is the dynamic modification of chromatin architecture to allow access of condensed genomic DNA to the regulatory transcription machinery proteins, and thereby control gene expression. Such remodeling is principally carried out ...
.
Diagnosis
The diagnosis of CHARGE syndrome is often difficult, because it is rare. The syndrome spans many disciplines, and as such, can be diagnosed by a pediatrician, family medicine physician,
oral and maxillofacial surgeon, ENT specialist, ophthalmologist, endocrinologist, cardiologist, urologist, developmental specialist, radiologist, geneticist, physiotherapist, occupational therapist, speech therapist, or orthopedic specialist.
Signs
Although
genetic test
Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, o ...
ing positively identifies nearly two thirds of children with CHARGE syndrome, diagnosis is still largely clinical.
The following signs were originally identified in children with this syndrome, but are no longer used to make the diagnosis alone.
* C –
Coloboma
A coloboma (from the Greek , meaning defect) is a hole in one of the structures of the eye, such as the iris, retina, choroid, or optic disc. The hole is present from birth and can be caused when a gap called the choroid fissure, which is pres ...
of the
eye,
central nervous system
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all par ...
anomalies
* H –
Heart defects
A congenital heart defect (CHD), also known as a congenital heart anomaly and congenital heart disease, is a defect in the structure of the heart or great vessels that is present at birth. A congenital heart defect is classed as a cardiovascular ...
* A –
Atresia of the choanae
* R – Retardation of growth and/or development
* G – Genital and/or urinary defects (
hypogonadism
Hypogonadism means diminished functional activity of the gonads—the testes or the ovaries—that may result in diminished production of sex hormones. Low androgen (e.g., testosterone) levels are referred to as hypoandrogenism and low estrogen ...
,
undescended testicles
Cryptorchidism, also known as undescended testis, is the failure of one or both testes to descend into the scrotum. The word is from Greek () 'hidden' and () 'testicle'. It is the most common birth defect of the male genital tract. About 3% of ...
, besides
hypospadias
Hypospadias is a common variation in fetal development of the penis in which the urethra does not open from its usual location in the head of the penis. It is the second-most common birth abnormality of the male reproductive system, affecting abou ...
)
* E – Ear anomalies and/or
deafness
Deafness has varying definitions in cultural and medical contexts. In medical contexts, the meaning of deafness is hearing loss that precludes a person from understanding spoken language, an audiological condition. In this context it is written ...
and abnormally bowl-shaped and concave ears, known as "lop ears".
Genetic testing
Genetic testing for CHARGE syndrome involves specific genetic testing for the CHD7 gene. The test is available at most major genetic testing laboratories. Insurance companies sometimes do not pay for such genetic tests, though this is changing rapidly as genetic testing is becoming standard across all aspects of medicine. CHARGE syndrome is a clinical diagnosis, which means genetic testing is not required in order to make the diagnosis. Rather, the diagnosis can be made based on clinical features alone.
Screening other organ systems
Once the diagnosis is made based on clinical signs, it is important to investigate other body systems that may be involved. For example, if the diagnosis is made based on the abnormal appearance of the ears and developmental delay, it is important to check the child's hearing, vision, heart, nose, and urogenital system. Ideally, every child newly diagnosed with CHARGE syndrome should have a complete evaluation by an ENT specialist, audiologist, ophthalmologist, pediatric cardiologist, developmental therapist, and pediatric urologist.
Treatment
Children with CHARGE syndrome may have a number of life-threatening medical conditions; with advances in medical care, these children can survive and can thrive with the support of a multidisciplinary team of medical professionals. Therapies and education must take into consideration hearing impairment, vision problems, and any others. Early intervention, such as occupational, speech-language, and physical therapy, to improve static posture, ambulation, and self-care skills is important. The intelligence of children with multiple health impairments, such as combined
deafblindness
Deafblindness is the condition of little or no useful hearing and little or no useful sight. Different degrees of vision loss and auditory loss occur within each individual. Because of this inherent diversity, each deafblind individual's needs re ...
, can be underestimated in the absence of early intervention.
Education
Children with CHARGE syndrome will vary greatly in their abilities in the classroom: some may need little support, while some may require full-time support and individualized programs.
Taking each of the various affected body systems into account is vital to the success of the child in the educational setting.
An important step in dealing with abnormal behavior is understanding why it is occurring and helping the child learn more appropriate methods of communicating.
Epidemiology
The incidence is estimated to range from 0.1 to 1.2 per 10,000 live births, though the true incidence is unknown.
As of 2005, the highest prevalence was found in Canada and estimated at 1 in 8,500 live births.
History
B.D. Hall first described the CHARGE association in a 1979 journal paper of about 17 children who had been born with
choanal atresia
Choanal atresia is a congenital disorder where the back of the nasal passage (choana) is blocked, usually by abnormal bony or soft tissue (membranous) due to failed hole development of the nasal fossae during prenatal development. It causes persi ...
. During the same year, H.M. Hittner described 10 children who had choanal atresia as well as coloboma, congenital heart defect, and hearing loss. Using both coloboma or choanal atresia and some of the other related characteristic malformations, R. A. Pagon first coined the acronym CHARGE in 1981 to emphasize that this cluster of associated malformations occurred together.
It came to be recognised as a syndrome within the umbrella of the CHARGE association, a set of apparently random signs occurring together. Since the signs seen in CHARGE are caused by a genetic anomaly, its name was eventually changed to 'CHARGE syndrome'.
Th
CHARGE Syndrome Foundation formally incorporated in 1993, is a US-based organization for individuals with CHARGE syndrome, families, researchers, and clinicians to further research and scientific knowledge about CHARGE Syndrome. The Foundation holds a biennial international conference that was first held in 1993.
References
External links
The CHARGE Syndrome Foundationnowiki/>
{{Multiple abnormalities , state=autocollapse
Genetic diseases and disorders
Syndromes affecting the eye
Syndromes affecting the heart
Syndromes affecting hearing
Intersex variations