Contents
What is Cri du chat syndrome
Cri du chat syndrome is a genetic disorder that result from missing a piece of chromosome number 5, also known as 5p- (5p minus) syndrome or cat cry syndrome. Cri du chat syndrome’s name is based on the infant’s cry, which is high-pitched and sounds like a cat. Research into Cri du Chat syndrome has shown that the larger the size of the chromosomal deletion, the more pronounced the physical characteristics are among individuals with Cri du Chat syndrome.
Infants with Cri-du-chat syndrome often have a high-pitched cry that sounds like that of a cat. Cri-du-chat syndrome is characterized by intellectual disability and delayed development, small head size (microcephaly), low birth weight, and weak muscle tone (hypotonia) in infancy. Affected individuals also have distinctive facial features, including widely set eyes (hypertelorism), low-set ears, a small jaw, and a rounded face. Some children with Cri-du-chat syndrome are born with a heart defect.
Cri du chat syndrome symptoms include:
- Cry that is high-pitched and may sound like a cat
- Downward slant to the eyes
- Low birth weight and slow growth
- Low-set or abnormally shaped ears
- Intellectual disability
- Partial webbing or fusing of fingers or toes
- Single line in the palm of the hand
- Skin tags just in front of the ear
- Slow or incomplete development of motor skills
- Small head (microcephaly)
- Small jaw (micrognathia)
- Wide-set eyes
Cri-du-chat syndrome occurs in an estimated 1 in 20,000 to 50,000 newborns 1. Cri-du-chat syndrome is slightly more common in girls. Cri-du-chat syndrome is found in people of all ethnic backgrounds.
Cri-du-chat syndrome usually happens by chance, but in 10-15% of cases it’s inherited. If you have a child with Cri du Chat syndrome, you can choose to have your own chromosomes tested if you’re thinking of having more children.
While there is no specific treatment available for Cri-du-chat syndrome, early intervention is recommended in the areas of physical therapy (achieving physical and motor milestones such as sitting and standing up), communication (speech therapy, sign language instruction), behavioral modification (for hyperactivity, short attention span, aggression), and learning (special education) 2. Because symptoms may vary from individual to individual, it is recommended that parents discuss these options with a health care professional to develop a personalized plan for therapy.
Cri du chat syndrome facts
- Cri du Chat syndrome is a rare genetic disorder that causes health problems and intellectual disability.
- Cri-du-chat syndrome is rare and happens in around 1 in 20,000-50,000 births.
- Cri-du-chat syndrome usually happens by chance, but in 10-15% of cases it’s inherited. If you have a child with Cri du Chat syndrome, you can choose to have your own chromosomes tested if you’re thinking of having more children.
- Health professionals can diagnose Cri du Chat syndrome based on the syndrome’s distinctive cry. Genetic testing can confirm the diagnosis.
- Most children with Cri du Chat syndrome are friendly, loving and affectionate.
- Early intervention can improve outcomes for children with Cri Du Chat syndrome.
Cri du chat syndrome life expectancy
Most individuals with Cri du chat syndrome have a normal life expectancy. A small number of children with Cri-du-chat syndrome are born with serious organ defects and other life-threatening medical problems. These children may have a worse prognosis. In these cases, it is best to obtain information about prognosis from the affected person’s physician.
Cri du chat syndrome prognosis
Intellectual disability is common. One half of children with Cri du chat syndrome learn enough verbal skills to communicate. The cat-like cry becomes less noticeable over time.
Cri du chat syndrome causes
Cri-du-chat 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.
Cri du chat syndrome karyotype
Cri-du-chat syndrome is caused by a deletion of the end of the short (p) arm of chromosome 5.
Cri du chat syndrome inheritance pattern
Most cases of Cri-du-chat syndrome are not inherited. The deletion occurs most often as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development. Affected people typically have no history of the disorder in their family.
About 10 percent of people with Cri-du-chat syndrome inherit the chromosome abnormality from an unaffected parent. In these cases, the parent carries a chromosomal rearrangement called a balanced translocation, in which no genetic material is gained or lost. Balanced translocations usually do not cause any health problems; however, they can become unbalanced as they are passed to the next generation. Children who inherit an unbalanced translocation can have a chromosomal rearrangement with extra or missing genetic material. Individuals with Cri-du-chat syndrome who inherit an unbalanced translocation are missing genetic material from the short arm of chromosome 5, which results in the intellectual disability and health problems characteristic of this disorder.
Cri du chat syndrome prevention
There is no known prevention for Cri du chat syndrome. Couples with a family history of this syndrome who wish to become pregnant may consider genetic counseling.
Resources for locating a genetics professional in your community are available online:
- The National Society of Genetic Counselors (https://www.findageneticcounselor.com/) offers a searchable directory of genetic counselors in the United States and Canada. You can search by location, name, area of practice/specialization, and/or ZIP Code.
- The American Board of Genetic Counseling (https://www.abgc.net/about-genetic-counseling/find-a-certified-counselor/) provides a searchable directory of certified genetic counselors worldwide. You can search by practice area, name, organization, or location.
- The Canadian Association of Genetic Counselors (https://www.cagc-accg.ca/index.php?page=225) has a searchable directory of genetic counselors in Canada. You can search by name, distance from an address, province, or services.
- The American College of Medical Genetics and Genomics (http://www.acmg.net/ACMG/Genetic_Services_Directory_Search.aspx) has a searchable database of medical genetics clinic services in the United States.
Cri du chat syndrome symptoms
The most obvious physical sign of Cri-du-chat syndrome is a cat-like cry in infancy. This is caused by problems in the baby’s larynx and nervous system. A third of children lose the cry by the time they’re two years old.
Other common physical signs and symptoms of Cri-du-chat syndrome might include:
- feeding problems because of difficulty swallowing and sucking
- low birth weight and poor physical growth
- lots of drooling
- constipation
- microcephaly (small head)
- wide-apart eyes, eyes looking in different directions (squint), skin tags in front of the eyes, and skin folds covering the inner corner of the eyes
- low muscle tone
- small jaw and low-set ears
- short fingers and lines that run across the palms (single palmar creases).
Less common symptoms include hearing loss and deformities of the skeleton.
Affected infants may also display low birth weight, growth deficiencies, diminished muscle tone (hypotonia), and microcephaly, a condition that indicates that head circumference is smaller than would be expected for an infant’s age and sex.
Distinctive facial features may include an abnormally round or plump (moon) face, a broad nasal bridge, widely spaced eyes (hypertelorism), crossed eyes (strabismus), downwardly slanting eyelid folds (palpebral fissures), vertical skin folds that may cover the eyes’ inner corners (epicanthal folds), low-set ears, and an abnormally small jaw (micrognathia). Improper alignment of the upper and lower teeth (malocclusion) may also occur.
Additional facial features include an abnormally small distance from the upper lip to the nose (short philtrum), incomplete closure of the roof of the mouth (cleft palate), an abnormal groove or gap in the upper lip (cleft lip), and abnormal fullness of the lower lip. In addition, the fleshy mass (uvula) that hangs in the back of the throat may be spilt (bifid uvula). As affected infants age the face may lose its plumpness and become abnormally long and narrow.
Most affected infants also display some degree of psychomotor and intellectual disability. Psychomotor disability is a delay in the acquisition of skills requiring mental and muscular activities such head control, sitting up, and walking. About half of children with Cri-du-chat syndrome were able to dress themselves by age 5 years. Moderate to severe intellectual disability is present in most cases. Speech development is especially delayed in children with Cri du chat syndrome. Affected children usually understand speech better than they can communicate. Some children may display hyperactivity or self-abusive behaviors. While children with cri du chat syndrome are born hypotonic (low muscle tone), they tend to become hypertonic (high muscle tone) as they grow older.
Affected infants may have feeding difficulties due to low muscle tone, poor suck, and gastroesophageal reflux disease. Some are also at risk for aspiration which can lead to pneumonias. In one study, only 50% of children with Cri-du-chat syndrome were able to feed themselves with a spoon by 3.5 years of age.
A variety of additional findings may occur in association with cri du chat syndrome. Abnormal side-to-side curvature of the spine (scoliosis) is a frequent complication. Affected children also have a higher risk of ear infections and hearing loss. Approximately 15-20 percent of affected infants have congenital heart defects. The most common heart defect is patent ductus arteriosus, a condition in which the passage (ductus) between the blood vessel that leads to the lungs (pulmonary artery) and the major artery of the body (aorta) fails to close after birth.
Less common findings associated with Cri-du-chat syndrome include the development of a tear in the supportive tissue of the lower abdomen (inguinal hernia) allowing a portion of the intestines to protrude out; the passage or flowing back (reflux) of the contents of the stomach or small intestines (duodenum) into the esophagus (gastroesophageal reflux); abnormalities of the kidney and urinary tract; respiratory difficulties; webbing of the fingers and toes (syndactyly); abnormal bending or curving of the pinkies inward toward the fourth finger (clinodactyly); clubfeet; and structural anomalies of the voice box (larynx). In some cases, nearsightedness (myopia) and cataracts may develop. Prematurely graying of the hair has also been reported. Some individuals may develop repeated respiratory and intestinal infections. In affected male infants, the testes may fail to descend into the scrotum (cryptorchidism) and the urinary opening may be located on the underside of the penis (hypospadias). There has also been an association with Cri-du-chat syndrome and Hirschsprung’s disease.
Developmental signs
Children with Cri du Chat syndrome usually have some motor delay, especially in walking. Some children walk as early as two years, but others can take up to six years because of low muscle tone. Some might never walk.
Cognitive signs
Children with Cri du Chat syndrome can have mild to profound intellectual disability. This might include language difficulties ranging from mild speech delay to severe language disorder. Some children might never be able to talk.
Behavior signs
Children with Cri du Chat syndrome can have behaviour problems that might include:
- sleeplessness
- hyperactivity
- aggression
- tantrums
- repetitive movements.
Medical problems
Children with Cri du Chat syndrome can have medical problems, including heart problems, hernias, kidney problems and gastric reflux.
Cri du chat syndrome possible complications
Cri du chat syndrome complications depend on the amount of intellectual disability and physical problems. Symptoms may affect the person’s ability to care for themselves.
Cri du chat syndrome diagnosis
Health professionals can diagnose Cri du Chat syndrome based on the syndrome’s distinctive cry. They also look for the physical signs and problems that usually come with the cry. Cri du Chat syndromecan be confirmed with genetic testing. Genetic tests can show a missing part of chromosome 5. Skull x-ray may reveal any problems with the shape of the base of the skull.
Health professionals will perform a physical exam. This may show:
- Inguinal hernia
- Diastasis recti (separation of the muscles in the belly area)
- Low muscle tone
- Epicanthal folds, an extra fold of skin over the inner corner of the eye
- Problems with the folding of the outer ears
Cri du chat syndrome treatment
There is no specific treatment for Cri du chat syndrome. Your doctor will suggest ways to treat or manage the symptoms. Treatment may require the coordinated efforts of a team of specialists. Pediatricians, orthopedists, surgeons, cardiologists, speech pathologists, neurologist, dentist, physical and occupational therapists, and other health care professionals may need to systematically and comprehensively plan an affected child’s treatment. As some children with Cri du chat syndrome can have sensory-neural deafness, auditory testing should be performed.
Parents of a child with this syndrome should have genetic counseling and testing to determine if one parent has a change in chromosome 5.
Early intervention is important in ensuring that children with Cri du chat syndrome reach their highest potential. Services that may be beneficial may include special remedial education, physical therapy, speech therapy, special services, and other medical, social, and/or vocational services. Most children are enrolled in therapy before one year of age.
Surgery may be performed to treat a variety of symptoms potentially associated with Cri du chat syndrome including congenital heart defects, strabismus, scoliosis, clubfoot, cleft palate and cleft lip.
The survival for children with Cri du chat syndrome is generally good. Most syndrome related deaths occur within the first year of life. Several children have lived to be over 50 years of age.
Early intervention services for children with Cri du Chat syndrome
Although there’s no cure for Cri du Chat syndrome, early intervention can make a difference. Through early intervention services, you can work with health professionals to choose therapy options to treat your child’s symptoms, support your child, improve outcomes for your child and help your child reach his full potential.
The team of professionals involved in supporting you and your child might include pediatricians, physiotherapists, audiologists, speech pathologists, occupational therapists and special education teachers.
Together, you and your team can choose treatment and therapy options to best help your child.
