CRI-DU-CHAT SYNDROME
Brief Summary
Cri-du-chat, also known as 5p- (5p minus) syndrome, is a chromosomal condition caused by partial chromosome 5 (5p) deletion of the p arm, and is characterized by a distinctive, high-pitched catlike cry with growth failure, facial abnormalities, microcephaly, and lifelong mental retardation in infancy.
Frequency
It occurs in an estimated 1 in 20,000 to 50,000 newborns
Inheritance
Most cases of cri du chat syndrome are not inherited because is considered a sporadic genetic condition, meaning it usually occurs as a result of a random event (deletion of a portion of chromosome 5) during the formation of reproductive cells or early development.
History of Disease
Dr. Jerôme Lejeune described a syndrome in 1963 consisting of multiple congenital anomalies, mental retardation, microcephaly, abnormal face, and mewing cry in infants with deletion of a chromosome of the B group (Bp-), later recognized as 5p-. Following the distinctive cat-like cry, he named the disorder as "Cri du chat" which translates into "cry of the cat" in French.
Pathogenesis
Achondroplasia is caused by a mutation in the FGF3 gene in chromosome 4 at 4p 16.3. This mutation causes a decreased production of fibroblast growth factor receptor 3 which is crucial in the conversion of cartilage into bone which is vital in the proper development of a person. This mutation is inherited in an autosomal dominant manner. More than 80 percent of people with achondroplasia have parents with normal characteristics and are born with achondroplasia due to a recent (de novo) gene modification (mutation).
Pathogenesis
Cri du chat syndrome is a chromosomal disorder caused by partial deletion (monosomy) of the short arm (p) of chromosome 5 of varying lengths. The minority of cases involving cri-du-chat are inherited; usually, the parent possessing the genetic abnormality is unaffected by the condition due to a phenomenon called balanced translocation (chromosomal rearrangement in which there is no net gain or loss of genetic material). During fetal development or during the production of eggs and sperm, the remaining cases are caused by spontaneous chromosome deletion.
Symptoms
1
small chin
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unusually round face
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small bridge of the nose
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folds of skin over the eyes
5
abnormally wide-set eyes
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abnormally shaped or low-set ears
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small jaw
8
partial webbing of the fingers or toes
Social Concerns
The everyday lives of patients and families will be affected by dealing with a hereditary or unusual disorder. Such tools can allow families to manage diverse ways of dealing with a rare disorder.
Cri du chat syndrome's behavioral profile tends to be that of self-injurious actions, repeated gestures, excessive attention to objects, visual sensation, hypersensitivity, stubbornness, and clumsiness. In fact, few infants displayed autism symptoms (Ex. gaze evasion, social isolation), difficulties with eating or sleeping, or mood disturbances. The degree to which these talents begin to evolve in adulthood is not yet understood, but it is doubtful that people with the condition will be able to survive independently, given the nature of the difficulties.
Treatment
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Cri du chat syndrome therapy is geared towards the particular symptoms that are evident in each person. The combined activities of a team of clinicians may be needed for treatment. The treatment of an affected infant may need to be routinely and comprehensively prepared by pediatricians, orthopedists, physicians, cardiologists, speech pathologists, neurologists, dentists, physical and occupational therapists, and other health care practitioners.
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Early intervention is necessary to ensure that children with cri du chat syndrome have the greatest potential. Special remedial schooling, occupational rehabilitation, speech therapy, special care, and other educational, social, and/or vocational services may be services that may be helpful. Before one year of age, most infants are involved in counseling.
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Surgery can be done to relieve several complications, including congenital heart defects, strabismus, scoliosis, clubfoot, cleft palate, and cleft lip, possibly linked with cri du chat syndrome.
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Survival for kids with cri du chat is usually fine. Half of the syndrome-related deaths occur in the first year of life. Several children have survived to be above the age of 50.
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Genetic therapy is prescribed for affected people and their relatives. Some therapies are symptomatic and supportive.
Clinical Trials
Title:
SNP-based Microdeletion and Aneuploidy RegisTry (SMART)
Intervention Phase:
Four hundred sixty-nine samples (358 plasma samples from pregnant women, 111 artificial plasma mixtures) were amplified with the use of a massively multiplexed polymerase chain reaction, sequenced, and analyzed with the use of the Next-generation Aneuploidy Test Using SNPs algorithm for the presence or absence of deletions of 22q11.2, 1p36, distal 5p, and the Prader-Willi/Angelman region.
Procedure:
The purpose of this study is to collect blood from families with a child who has been diagnosed with a chromosomal disorder including microdeletions.
Goal:
To further develop a non-invasive prenatal screening test based on fetal DNA isolated from maternal blood.
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