G.D Flashcards
refers to differential expression of genetic material and allows researchers to identify whether the chromosomal material has come from the male or female parents
Imprinting
disorder caused by a deletion or disruption of genes in the proximal arm of chromosome 15 or by maternal disomy in the proximal arm of chromosome 15 no paternal contribution is presented at certain gene point
Prader- willi syndrome (PWS)
what are the characteristics of pws?
diminished fetal activity
obesity
hypotonia
intellectual disability
short stature
hypogonadotropic hypogonadism
strabismus
small hands and feet
Is a condition in which the male testes or the female ovaries produce little or no sex hormones
hypogonadism
Is a form of gonadism that is due to a problem with the pituitary gland or hypothalamus
Hypogonadotrophic Hypogonadism
Occurs not because of dominant recessive gene pattern but through a fault in the number of structure of chromosome which result in the number or result to missing or distorted gene
Chromosomal disorder or cytogenetic disorder
number of chromosome and specific parts of chromosomes
karyotype
process termed fluorescent in situ hybridization (FISH) or 24 chromosome single nucleotide polymorphysim (SNP)
Karyotyping
chromosome disorder occur if the division is uneven
non disjunction disorder
a genetic syndrome that results when a boy is born with extra copy of the X chromosome.
Klinefelter syndrome (XXY)
Klinefelter syndrome (XXY) cause?
testicular growth(smaller than normal)
reduce muscle mass
reduced body and facial hair
enlarged breast tissue
(most men with KS)produce little or no sperm
results from loss of parts of chromosomes
rarely suspected prenatally but may be incidentally discovered at that time if karyotyping is done for other reasons
chromosomal deletion syndrome
type of down syndrome that is cause when one chromosome breaks off and attaches to other chromosome
translocation disorder
rare form of down syndrome
have mixture of cells, some have two copies of chromosome 21, and some have 3
mosaic down syndrome or mosaicism
mosaic down syndrome or mosaicism typically have?
slower speech
lower IQ
flattened face
small ears
shorter height
slanting up eyes
white spots on the iris of the eye
if a chromosomes accidentally divides not by a vertical separation, but a horizontal one, a new chromosomes with mismatched long and short arms can result
it has the same effect as translocation disorder when an entire extra chromosomes exists
some instance of turner syndrome
Isochromosomes
a process by which patients or relatives, at risk of an inherited disorder, are advised of the consequences and nature of the disorder, the probability of
developing or transmitting it and the options open to them in management and family planning in order to prevent or avoid it.
genetic counseling
components of genetic counseling
•Contracting (ascertaining patient’s questions/concerns; providing overview of clinic visit)
• Information gathering (family and medical histories)
• Physical examination (if indicated)
• Risk assessment (determination of likely pattern(s) of inheritance, risks)
• Education about genetic condition (clinical features, prognosis, management, inheritance and implications for patient and family members)
• Ascertaining and addressing psychosocial issues/concerns
• Discussion of genetic tests/other tests/evaluations/referrals to consider
• Provision of resources about the genetic condition and contact information for national organizations/support groups
• Facilitating decision-making
genetic counseling ethics
• Respect the right of individual (autonomy)
• Non- directive approach
• Keep privacy of individual and family
• Maintain the communication between counsellor and his client
types of genetic screening
- Carrier identification
- Prenatal diagnosis
- Newborn screening
- Forensic screening
(paternity test)
