CYTOGENETIC DISORDER P.2 Flashcards
2 types of structural anomalies
Wolf-Hirschhorn Syndrome and Cri-Du-Chat
Individuals with such syndrome are with terminal deletion of the short arm of chromosome 4, del(4)(p16)
Wolf-Hirschhorn Syndrome
Wolf-Hirschhorn syndrome is also known as?
4p Syndrome
This syndrome has microcephaly, frontal bossing, micrognathia, hypotonia, epicanthal folds, and developmental delay
Wolf-Hirschhorn Syndrome
It has Greek warrior’s facial helmet appearance due to arched eyebrows, prominent glabella, hypertelorism, and long beaked nose
Wolf-Hirschhorn Syndrome
Individuals with such syndrome have deletion of the short arm of chromosome 5, del(5)(p15)
Cri-Du-Chat
People withy this syndrome present with high-pitched, cat-like cry in infancy, low birth weight, slow growth, hypotonia, microcephaly, hypertelorism, mental retardation, and cardiac anomalies
Cri-Du-Chat
Patients have delayed development and may reach cognitive and social level of a 5 or 6 year-old.
Cri-Du-Chat
Cri-Du-Chat is also known as?
5p Syndrome
fraction of a single chromosome band
Microdeletions
It can maybe enough to be identified by karyotyping, but most may require FISH
Microdeletions
single to several hundred base pair and are identified by molecular technology
Molecular Deletions
those that are due to deletions that encompass several adjacent, unrelated genes resulting in variable phenotypic expression
Contiguous Deletion
deletion of the elastin gene on the proximal long arm of chromosome 7 (7q11.23)
Williams Syndrome
Unequal meiotic crossover → interstitial deletion
Williams Syndrome
present with low IQ with behavioral anomalies and hypersensitivity to sound
Williams Syndrome
they have blue eyes with stellate pattern in the iris
Williams Syndrome
They have prominent lips, hoarse voice, cardiac defects, premature aging skin and hypercalcemia.
Williams Syndrome
This is due to del 8q24.11-q24.13, involving the
TRPSI(Tricorhinophalangeal syndrome 1),
TRPSII(Tricorhinophalangeal syndrome 2), EXT
genes
Langer-Giedion Syndrome
These individuals present with craniofacial
dysmorphism, exostosis (overgrowth of bone),
skeletal abnormalities, mild to severe mental
deficiency
Langer-Giedion Syndrome
They have fine scalp hair, large and prominent ears
and missing teeth
Langer-Giedion Syndrome
Clinicolradiologic diagnosis, Karyotyping and molecular genetic analysis
Langer-Giedion Syndrome
WAGR stands for?
Wilm’s tumor, Aniridia, Genitourinary
defects and mental Retardation
This is secondary to deletion on the short arm of
chromosome 11 (11p13.3) involving WT1 gene, AN2
gene causing contiguous gene syndrome
WAGR Syndrome
Except for Wilm’s Tumor locus, each of the three
other anomalies (aniridia, genitourinary defects and
mental retardation) has been associated with a
particular gene arranged in tandem on the short arm
of chromosome 11 (True or False)
True
The Del 13q14, 1-q14.2, involving Rb gene
Retinoblastoma
May also occur by hypermethylation of the promoter
sequence and Patients have risk of developing tumors of the
retinoblast cells of the eye
Retinoblastoma
What are the 4 different stages of Retinoblastoma?
Leukoria, Glauccomatous, Extra-occular, and Reccurence
There is an increase on the pressure of the
eye, this is secondary to the enlargement of the
tumor
Glauccamatous
With the continuous enlargement, there will be
outgrowth/extraocular growth of the tumor. This will be enucleated, the eye will be removed with the tumor.
Extra-occular
PRADER-WILLI and ANGELMAN
SYNDROMES is best known as?
Microdeletions syndrome
Prader-willi imprinted by?
Maternal
Prader-Willi del(15)(q11.2-q13) by?
paternal
Prader-Willi manifestations?
Small but gain weight
Angelmann imprinted by?
paternal
Angelmann del(15)(q11.2-q13) by?
maternal
Angelmann description?
Happy puppets
Angelmann manifestaions?
Severely mental retardation
Rubinstein-Taybi Syndrome is also known as?
broad thumb-hallux syndrome
Del 16p13.3, CREBBP gene, regulates cell growth &
division for normal fetal development; EP300 gene,
small % of cases
Rubinstein-Taybi syndrome
It is the Del 17p11.2, RAI1 gene
Smith-Magenis Syndrome
It is Not inherited syndrome and Deleted during formation of reproductive cells
Smith-Magenis Sydnrome
Microdeletion of the distal short arm of chromosome
17 (17p13.3) involving the LIS1 gene, with deletion of
at least two genes; AD
Miller-Dieker syndrome and Lissencephaly
Lissencephaly has smooth brain (true or False)
True
is associated with
profound mental retardation and
seizure episodes
Lissencephaly
It is the most common microdeletion syndrome,
occurring in 1:4,000 live births but not often
recognized
Velocardiofacial Syndrome
3 Mb deletion on the proximal long arm of
chromosome 22 (22q11.2), ?GCSL gene
Velocardiofacial SYndrome
It is Usually diagnosed in newborns
because of feeding difficulties
due to presence of palatal
abnormalities (cleft palate),
cardiac defects (75% of these
patients), and characteristic
facial dysmorphisms with
prominent nose and retrognathia
Velocardiofacial Syndrome
del 22q11.2, 10p, 4q, 6q involving ?GCSL gene
Digeorge Syndrome
Characteristic facies, cleft palate, heart defect,
hypoplasia of the thymus (where T lymphocytes
mature) with resultant T-cell immunodeficiency,
parathyroid hypoplasia giving rise to severe
hypocalcemia, and seizure episodes
Digeorge Syndrome
It s is due to del Xp22.32, involving the STS
gene
ichthyosis
Individuals with this syndrome present with scaly skin,
short stature, hypogonadism and mental retardation
Ichthyosis
del Xp22.3, involving the KAL1 gene
Kallman Syndrome
Individuals with this syndrome present with
Hypogonadism and inability to smell
Kallman Syndrome
