Cri du chat syndrome

Answer 1

Definition

Cri du chat syndrome is a group of symptoms that result from missing a piece of chromosome number 5. The syndrome's name is based on the infant's cry, which is high-pitched and sounds like a cat.

Alternative Names

Chromosome 5p deletion syndrome; 5p minus syndrome; Cat cry syndrome

Causes, incidence, and risk factors

Cri du chat syndrome is rare. It happens when genetic information on chromosome 5 is missing. One missing piece, called TERT (telomerase reverse transcriptase) is involved in control of cell growth, and may play a role in how some of the features of this syndrome develop.

Most cases are believed to occur during the development of the egg or sperm. A minority of cases result from one parent carrying a rearrangement of chromosome 5 called a translocation and passing this on to the baby.

This syndrome may account for up to 1% of individuals with severe mental retardation.

Symptoms

• Cry that is high-pitched and sounds like a cat
• Downward slant to the eyes
• Low birth weight and slow growth
• Low-set or abnormally shaped ears
• Mental retardation
• Partial webbing or fusing of fingers or toes
• Single line in the palm of the hand (simian crease)
• Skin tags just in front of the ear
• Slow or incomplete development of motor skills
• Small head (microcephaly)
• Small jaw (micrognathia)
• Wide-set eyes

Signs and tests

In addition to symptoms, the physical examination may show:

• Inguinal hernia
• Diastasis recti(separated abdominal muscles)
• Low muscle tone
• Epicanthal folds, an extra fold of skin over the inner corner of the eye
• Incompletely or abnormally folded external ears

Genetic tests can show a missing part of chromosome 5. Skull x-ray may reveal an abnormal angle to the base of the skull.

Treatment

No specific treatment is available for this syndrome. The mental retardation must be addressed, and counseling is recommended for the parents.

Parents of a child with this syndrome should have genetic counseling and a karyotype test to determine if one parent has a rearrangement of chromosome 5.

Support Groups

5p- Society -- www.fivepminus.org

Expectations (prognosis)

What can be expected varies, but mental retardation is usual. Half of children with Cri du chat syndrome learn sufficient verbal skills to communicate. The cat-like cry becomes less apparent over time.

Complications

Complications depend on the extent of mental retardation and physical abnormalities. Complications may include:

• Inability to care for self
• Inability to function in society

Calling your health care provider

This is a diagnosis that is generally made in the hospital at birth. Your health care provider will discuss your baby's signs and symptoms with you. When you leave the hospital, it's important to maintain regular contact with your health care provider and other caregivers. Genetic counseling and testing is recommended for all persons with a family history of this syndrome.

Prevention

There is no known prevention. Couples with a family history of this syndrome who wish to become pregnant may consider genetic counseling.

References

Descartes M, Carroll AJ. Cytogenetics. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th Ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 81.

Answer 2

Definition

Cri du chat syndrome is a group of symptoms that result from missing a piece of chromosome number 5. The syndrome's name is based on the infant's cry, which is high-pitched and sounds like a cat.

Alternative Names

Chromosome 5p deletion syndrome; 5p minus syndrome; Cat cry syndrome

Causes, incidence, and risk factors

Cri du chat syndrome is rare. It is caused by a problem with chromosome 5.

Most cases are believed to occur during the development of the egg or sperm. A small number of cases occur when a parent passes a different, rearranged form of the chromosome onto their child.

Symptoms

• Cry that is high-pitched and sounds like a cat
• Downward slant to the eyes
• Low birth weight and slow growth
• Low-set or abnormally shaped ears
• Mental retardation (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

Signs and tests

The doctor will perform a physical exam. This may show:

• Inguinal hernia
• Diastasis recti(separatation 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

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.

Treatment

There is no specific treatment. Your doctor will suggest ways to treat or manage the symptoms.

Parents of a child with this syndrome should have genetic counseling and testing to determine if one parent has a change in chromosome 5.

Support Groups

5P- Society -- www.fivepminus.org

Expectations (prognosis)

Intellectual disability (mental retardation) is common. Half of children with this syndrome learn enough verbal skills to communicate. The cat-like cry becomes less noticeable over time.

Complications

Complications depend on the amount of intellectual disability (mental retardation) and physical problems. Symptoms may affect the person's ability to care for themself.

Calling your health care provider

This syndrome is usually diagnosed at birth. Your health care provider will discuss your baby's symptoms with you. It is important to continue regular visits with the child's health care providers after leaving the hospital.

Genetic counseling and testing is recommended for all persons with a family history of this syndrome.

Prevention

There is no known prevention. Couples with a family history of this syndrome who wish to become pregnant may consider genetic counseling.

References

Descartes M, Carroll AJ. Cytogenetics. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 81.

Reviewed By

Review Date: 08/04/2011

Chad Haldeman-Englert, MD, Wake Forest University School of Medicine, Department of Pediatrics, Section on Medical Genetics, Winston-Salem, NC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.