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    Cri Du Chat Syndrome

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    hadiqa aimen
    Cri du chat syndrome is caused by a deletion on chromosome 5p and results in a cat-like cry in infants. It can involve deletions of varying sizes on the short arm of chromosome 5. Phenotypic effects range from mild to severe developmental delays. While most cases are sporadic, familial inheritance is possible. There is heterogeneity even among family members with the same deletion, with factors like genomic imprinting possibly influencing severity. Treatment focuses on managing symptoms and providing support for developmental needs.

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    Cri Du Chat Syndrome

    Uploaded by

    hadiqa aimen
    351 views20 pages
    Cri du chat syndrome is caused by a deletion on chromosome 5p and results in a cat-like cry in infants. It can involve deletions of varying sizes on the short arm of chromosome 5. Phenotypic effects range from mild to severe developmental delays. While most cases are sporadic, familial inheritance is possible. There is heterogeneity even among family members with the same deletion, with factors like genomic imprinting possibly influencing severity. Treatment focuses on managing symptoms and providing support for developmental needs.

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    Cri du chat syndrome is caused by a deletion on chromosome 5p and results in a cat-like cry in infants. It can involve deletions of varying sizes on the short arm of chromosome 5. Phenotypic effects range from mild to severe developmental delays. While most cases are sporadic, familial inheritance is possible. There is heterogeneity even among family members with the same deletion, with factors like genomic imprinting possibly influencing severity. Treatment focuses on managing symptoms and providing support for developmental needs.

    Copyright:

    © All Rights Reserved
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
    351 views20 pages

    Cri Du Chat Syndrome

    Uploaded by

    hadiqa aimen
    Cri du chat syndrome is caused by a deletion on chromosome 5p and results in a cat-like cry in infants. It can involve deletions of varying sizes on the short arm of chromosome 5. Phenotypic effects range from mild to severe developmental delays. While most cases are sporadic, familial inheritance is possible. There is heterogeneity even among family members with the same deletion, with factors like genomic imprinting possibly influencing severity. Treatment focuses on managing symptoms and providing support for developmental needs.

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    © All Rights Reserved
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
    of 20

    Presented By

    Cri Du HADIQA AIMEN


    FA19/RMG/006
    Chat
    Syndrome
    (Cry of the Cat)
    Cri du chat syndrome, also
    known as chromosome 5p
    deletion syndrome

    5p deletions, whether terminal or


    interstitial, occur at different
    breakpoints
    Introduction
    Discovered by a geneticist
    named Jerome Lejeune

    The variability seen among individuals


    may be attributed to the differences in
    their genotypes.
    Genetics graphics
    Molecular Characterization
    • 5p deletions can be interstitial or terminal and range from 560 kb to
    40 Mb in size
    • not have any terminal deletions greater than 33 Mb
    • 5p deletions are most commonly de novo occurrences
    • which are paternal in origin in 80–90% of cases
    • Terminal deletions comprise 80–90% of cases and interstitial deletions
    account for 3–5% 
    • Less common mechanisms include mosaicism (1.4%), inversions
    (0.5%), or ring chromosomes (0.5%)
    Chromosome 5p
    gene dosage map
    • There is also phenotypic heterogeneity among family members with
    the same deletion
    • parents of affected children with 5p– deletions who themselves have
    the same deletion yet do not appear to have any symptoms 
    • siblings born to these parents, despite having inherited the same
    deletion, vary with respect to features such as growth and
    development 
    • No imprinted genes have been identified
    • Following factors had not been explored
    • effects of modifier genes
    • additional copy number variants
    • mutations or allelic variation in the homologous allele
    • occult duplications
    • epigenetic modifications
    • coexisting diagnoses
    • variable expressivity
    • environmental factors
    • members of families in which the deletion was maternally inherited
    were observed to have only mild growth and developmental delays
    versus families in whom it was paternally inherited

    • If there are de novo cases with the same breakpoints, a comparison


    analysis of those whose hemizygous alleles are paternal versus
    maternal in origin may elucidate whether phenotypic differences exist
    Inheritance
    • Caused by a dominant trait.
    • CTNND2 is an important gene
    • CTNND2 gene usually makes the
    delta catenin protein.
    • This protein works in the nervous
    system and helps with cell
    movement.
    • The loss of CTNND2 may cause
    Delta Catenin protein severe brain damage in some
    patients.
    • The TERT gene provides instructions for making one
    component of an enzyme called telomerase. Telomerase
    TERT maintains structures called telomeres, which are composed of
    repeated segments of DNA found at the ends of chromosomes.
    Telomeres protect chromosomes from abnormally sticking
    together or breaking down (degrading).
    Detailed map of the cat-like cry ‘critical region’. (a) STS marker positions, (b) known genes and EST
    sequences identified and (c) predicted exons identified by Genscan program in the cat-like cry ‘critical
    region’. Plus and minus mark the two different DNA strands
    No specific treatment

    Treatment Genetic counseling

    Therapy to improve skills needed in life


    like:
    language skills
    motor skills
    Statistics
    90% randomly-occurring deletion

    10% occurs purely by inheritance

    1 in 20,000 to 50,000 newborns

    The male to female ratio is 3:4

    30% of infants with cri-du-chat have heart defects

    1/3 of infants lose the catlike cry at age 2


    Conclusion
    • htmhttp://rarediseases.about.
    com/cs/criduchatsynd/a/010
    704.htm

    Works cited • http://health.nytimes.com/he


    alth/guides/disease/cri-du-
    chat-syndrome/overview.html
    • http://www.ghr.nlm.nih.gov/co
    ndition/cri-du-chat-
    syndrome#genes
    • http://www.ncbi.nlm.nih.gov/p
    mc/articles/PMC1574300/
    • http://www.criduchat.asn.au/crid
    uchat/joel
    • https://onlinelibrary.wiley.com/doi
    /pdf/10.1002/ajmg.c.31444

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