Microarray CGH: This method employs array elements that are prepared from large-insert genomic clones like BACs or phage artificial chromosomes (PACs). Its measurement precision allows reliable revealing of single-copy abnormalities affecting individual clones.
what is Skeletal radiography
This technique can highlight microcephaly, cranial base malformations such as lower cranial base angle or abnormally formed sella turcica and clivus, retromicrognathia, disproportionately short metacarpals (especially third, fourth and fifth) and disproportionately long proximal phalanges (especially second, third, fourth and fifth).
what is Chromosome comparative genomic hybridization
Chromosome comparative genomic hybridization (CGH): This technique is able to screen the whole genome for any DNA copy-number alterations in just a single hybridization. However, the results cannot be mapped directly to genome sequence and the resolution is restricted to around 5-10 Mb.
What is Fluorescence in situ hybridization (FISH)
FISH : This technique employs genetic markers which are precisely localized in our interested areas. Molecular cytogenetic studies along with FISH help in a better diagnosis of the very small deletions of 5p. if a fluorescent signal is absent from either paternal or maternal 5p chromosome regions, it is a clear indication of monosomy for that chromosomal region.
Diagnosis and work-up for Cri du Chat Syndrome
The high-pitched, monotone, cat-like cry is the basis of diagnosis during infancy. Other signs include poor muscle tone, microcephaly, micrognathia, hypertelorism, epicanthic folds and mental retardation. Chromosomal testing of the embryo, referring to when the child is still in the womb of the mother is a means of testing the syndrome. A diagnostic expert can perform tests on two samples in this stage, (1) chronic villus sampling (CVS), wherein a tissue sample from outer part of the sac where the child grows is tested and (2) amniocentesis, wherein a sample of amniotic fluid is tested.
After birth, a physical examination of the infant can disclose some abnormalities such as inguinal hernia, diastasis recti, separated abdominal muscles, or abnormally folded ears. An X-ray of the skull reveals an abnormal angle at the bottom. Some of the laboratory tests and tests that are performed for the diagnosis of the syndrome include
Conventional cytogenetic studies: The amount of the deleted chromosome differs from only 5p15 to the whole of the short arm. These studies are unable to detect a small deletion, but they are very useful.
High-resolution cytogenetic studies: Since small deletions are unable to be detected by conventional cytogenetic studies, high-resolution cytogenetic studies were performed to detect them.
Fluorescence in situ hybridization (FISH)
Chromosome comparative genomic hybridization (CGH) (http://cri-du-chat-syndrome.blogspot.com/)
Microarray CGH: This method employs array elements that are prepared from large-insert genomic clones like BACs or phage artificial chromosomes (PACs).
Apart from the chromosomal studies, imaging studies can also be helpful.
Skeletal radiography
MRI: This method is employed to detect atrophic brainstem, middle cerebellar peduncles or cerebellar white matter, hypoplasia of cerebellar vermis along with extra-growth of cisterna magna and fourth ventricle.
Echocardiography: This technique is employed to check if there are any structural cardiac abnormalities.
The other tests include swallowing study, developmental testing and evaluation of receptive and expressive language.
Treatment for Cri du Chat Syndrome
There is no specific treatment currently available for this syndrome. However, gene therapy may help in the infant stages but this is not 100% effective. No techniques or methods have been developed until now to treat large chromosome abnormalities. Gene therapy addresses some of the effects due to the gene deletion. The development of a good technique may take several more years and will not be available in the immediate future.
Most of the associated medical problems can be treated with the available medical treatments successfully. Mental retardation must be treated without fail. It is recommended for the parents to attend a genetic counseling. The parents must undertake a karyotype test to check if one parent has a genetic rearrangement in chromosome 5.
Early intervention programs through several therapies or educational strategies have been planned to enhance the physical, intellectual, sensory and social development in the children. These must include physiotherapy, speech and language therapy, occupational therapy and behavioral management when necessary. All these treatments according to surveys have been shown to improve the future stance of the child greatly.
These treatments are essential since most of the children affected with the syndrome undergo severe speech developmental problems. When the child is taught an alternative means for communication like a sign language, (eg. Makaton) in addition to a pictorial symbol system, this will improve the language acquisition and speech development. Cri Du chat
In most of the affected children, they are keenly interested in learning the communication and in fact, many can even develop their own language in the form of signs and gestures in order to get their requirements. In such cases, these children prefer to use their own language over the formal language taught by schools or doctors.
But some children may undergo a lot of frustration owing to their communication problems and this may lead to behavioral problems at times. Hence speech and language therapy is of significant importance and helps such children to develop their intellectual skills and improve the quality of their living greatly. In case, this is not possible at young ages, a communication device may be of tremendous help for older children and adults without adequate speech knowledge. (http://cri-du-chat-syndrome.blogspot.com/)
Apart from such programs, medical care attention is necessary for chronic problems like upper respiratory tract infections, severe constipation and otitis media. Visual-motor coordination computerized training can help in enhancing the visuospatial performance.
Surgical care is essential in the cases of congenital heart disease, temperature maintenance, anatomical abnormalities in airways, mental retardation, hypotonia, undescended testes, clubfoot, and strabismus. There is nothing like a special diet for such children. They may eat and drink everything like a normal person. Full-time care by parents may be necessary in children who are severely affected all through their lives in spite of the treatments.
Medical Problems Associated with Cri Du Chat Syndrome
Children affected with cri du chat syndrome experience several medical problems soon after birth as well as during their growth as they grow old. During birth, the medical problems found in a few children include
• Heart defects, mostly ventral and atrial septal defects and rarely endocardial cushion defects and tetralogy of Fallot
• Rare occurrence of Cleft Palate
• Rare occurrence of kidney abnormalities
• Development of scoliosis in a few children
• Occasional occurrence of inguinal or abdominal hernias at birth
• Minor skeletal problems such as hip dislocation or deformities in the feet
• Bowel abnormalities
• Rare occurrence of epilepsy
• Intubation problems for anesthesia found in a very few cases owing to abnormal formations of larynx as well as epiglottis
• Problems with swallowing as well as sucking found in newborn babies but the swallowing difficulties sometimes prevail longer.
The additional problems that exist when the child grows are as follows
• Minor hearing problems. Impairment of hearing is severe rarely and needs hearing aids
• Turned eye or strabismus is common at times and needs to be consulted with a doctor since many individuals do not grow out of it like other problems and affects the vision. But treatment at the right time will help. Other visual problems may also persist. (http://cri-du-chat-syndrome.blogspot.com)
• Common occurrence of hypotonia or low muscle tone in infancy but may alter to high muscle tone or hypertonia as the child ages. In order to avoid this, physiotherapy is of tremendous help.
• Dysphagia or swallowing and sucking difficulties persist. The child will be able to suck weakly and may choke and cough while swallowing. Even this problem needs doctor treatment since aspiration pneumonia may result if not treated properly.
• Presence of gastrointestinal abnormalities in a few babies
• Common presence of gastric reflux in infancy and normally needs to be treated by a doctor.
• Common occurrence of chronic constipation, which can often start in the age when the child is one or two years and can also persist all through their lives. However, treatment exists and this problem can be managed well in almost all cases.
• The affected child obtains frequent ear infections to the extent that they need grommets in their childhood.
• The affected children also experience problem with controlling their saliva which leads to drooling. In the most severe cases where they have not been treated even at an older age, there will be a need for surgery. Hence get the child treated at an earlier age. cri du chat
• Common occurrence of dental problems owing to skeletal malformations
• The affected child does not take interest in food and ignores it
• Fatal owing to constant illness, refusal to drink or eat and severe reflux.
Genetic changes related to cri-du-chat
This syndrome is caused by a deletion of the end of the short (p) arm of chromosome 5. This chromosomal change is written as 5p-. The size of the deletion varies among affected individuals; studies suggest that larger deletions tend to result in more severe intellectual disability and developmental delay than smaller deletions.
The signs and symptoms of cri-du-chat syndrome are probably related to the loss of multiple genes on the short arm of chromosome 5. Researchers believe that the loss of a specific gene, CTNND2, is associated with severe intellectual disability in some people with this condition. They are working to determine how the loss of other genes in this region contributes to the characteristic features of cri-du-chat syndrome.
How common is cri-du-chat syndrome?
Cri-du-chat syndrome occurs in an estimated 1 in 20,000 to 50,000 newborns. This condition is found in people of all ethnic backgrounds.
other names of cri-du-chat syndrome
What other names do people use for cri-du-chat syndrome? There are 5 different names for this disease in all over the world. There are:
cat cry syndrome
chromosome 5p- Syndrome
5p deletion syndrome
monosomy 5p
5p- syndrome
Symptoms of Cri-du-chat syndrome
* Cat-like infant crying
* Cat-like cry in infants
* Abnormal laryngeal development in infants
* Low birth weight
* Severe mental retardation
* Severe growth retardation
* Small head
* Reduced muscle tone
* Round face
* Low set deformed ears
* Wide-set eyes
* Epicanthic folds
* Respiratory problems
* Feeding problems
* Scoliosis
* Cardiovascular defects
* Language delay
* Self-injury behavior
* Communication difficulties
* Headbanging
* Self-biting
* Low I Q
* Creases on the palm of hand
* Strabismus
* Simian crease
* Slightly short hand bones
* Malocclusion
* Harelip
* Cleft palate
* Failure to thrive
* Shuffling gait
Kaydol:
Kayıtlar (Atom)