Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Fundamentals 3- Heme > Clinical Medical Genetics > Flashcards

Clinical Medical Genetics Flashcards

1
Q

Why is it necessary to take a family history?

A
  1. diagnosis
  2. prognosis
  3. detection of pre-symptomatic disease
  4. prevention of clinical sequelae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the seven questions you need to ask a patient during the family history?

A
  1. Does anyone in the family have similar/identical disease or defect?
  2. Do family members have clinical characteristics associated with the disease?
  3. Do genetic diseases “run in the family”?
  4. Do all members of the sibship have the same parents?
  5. Are parent/grandparents related?
  6. Where did the ancestors come from/ are they a special social, ethnic or religious group?
  7. Is there a history of miscarriages, stillbirths, or abortions?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the six clues that a patient has a genetic disease?

A
  1. Definite proportion of the family
  2. not present in spouses/in-laws
  3. characteristic age of onset (early)
  4. multiple somatic abnormalities +/- mental retardation
  5. higher incidence in monozygotic than dizygotic
  6. multifocal tumors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What proportion of genes are shared with first degree relatives?
What are examples of first degree relatives?

A

1/2
Mom and dad to child
brothers and sisters to each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What proportion of genes are shared with second degree relatives?
What are examples of second degree relatives?

A

1/4
Grandparent to grandchild
niece/nephew to aunt/uncle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What proportion of the genes are shared by third degree relatives?
What are examples of third degree relatives?

A

1/8

Cousins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What proportion of genes are shared by fourth degree relatives?
What is an example of a fourth degree relative?

A

1/32

Second cousins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the eight indications for referral to a genetic counselor?

A
  1. known genetic disease in patient or family
  2. single/multiple malformations
  3. mental retardation/developmental delay
  4. advanced maternal age
  5. recurrent pregnancy loss
  6. teratogen exposure
  7. Consanguinity
  8. Family history of early onset tumor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe how to make a pedigree.

Where do you begin? (include all 3 names)

A
  1. Indicate the proband, propositus, index case (your patient) with an arrow
  2. Record current age, age of disease onset
  3. Add all first degree relatives
  4. Extend the side of the family suspected of having the mutant gene
  5. Record, age of onset and cause of death for all family members with similar signs/symptoms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do you politely inquire about paternity when taking a family history?

A

Do all the children of the sibship have the same parents?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the purpose of asking “Are the parents or grandparents related?”

A

assesses consanguinity which is inbreeding.

Consanguinity has a connection with increased autosomal recessive disorders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What racial, ethnic or religious group have higher incidences of:

  1. Sickle cell anemia
  2. Tay Sachs
  3. G6PD deficiency
  4. Cystic fibrosis
  5. Familial hypercholesterolemia
  6. b-thallasemia
A
  1. AA or Arabs
  2. Ashkenazi JEws
  3. AA or Mediterranean
  4. White
  5. Afrikaners
  6. Sardinians (Italian descent)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

In the family history, why do you ask where the parents ancestors came from and if they belong to special ethnic, religious or racial groups?

A

It can give information about :

  1. diseases that have more prevalence in certain races and religions
  2. the possibility of a genetic isolate (founders effect, genetic drift)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do you ask about abortions, stillbirths and miscarriages when taking a family history?

A

Most abortions/stillbirths/miscarriages are sporadic but if there are multiple:
50% of miscarriages and 4% of stillbirths are associated with chromosomal aberrations (usually balanced translocations)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the two items of interest to geneticists when taking a medical history? (NOT family history)

A
  1. Birth history– could the signs/symptoms be associated to complications with birth and environmental factors?
  2. Developmental history-
    - Did they hit developmental milestones
    - what level of schooling
    - grades? special classes?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How is the measurement of height broken up in the physical exam?
What are normal measurements?

A
  1. Head-to-pelvis should be shorter than pelvis-to-feet
  2. Arm span-to-height should be less than 1.05
    (it is greater in Marfan’s)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the characteristics of Prader-Willi syndrome? What genetic abnormality is associated with it?

A
  1. short, fat, small hands and feet, hypogonadism, mental retardation
    It is an example of maternal imprinting. The father passes the aberrant gene (deleted 15) and the mothers gene is imprinted so the abberant gene presents.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What 3 features of the head are measured?

A
  1. Circumference
  2. Shape (acrocephaly-pointed, scaphocephaly- narrow)
  3. Size (micro, macrocephaly)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the two abnormal head shapes we learned about?

A
  1. acrocephaly- “cone head”

2. scaphocephaly- narrow head (like continuation of the neck)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What 6 features of the eye are observed on physical exam?

A
  1. hypo, hypertelorism (width apart)
  2. epicanthal folds, up-slanting palpebral fissure (tri 21)
  3. Sclera color - bluish in osteogenesis imperfect
  4. Iris color- lisch, brushfield spots, kayser-fleishcher ring in Wilson’s copper deficiency)
  5. Strabismus
  6. Lens dislocation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are Lisch nodules? What disease are they associated with?

A

They are pigmented spots in the iris of patients with neurofibromatosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What features of the eye dictate trisomy 21?

A
  1. epicanthal folds
  2. up-slanting palpebral fissure
  3. Brushfield spots in the iris
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What feature of the eye is observed in Wilson’s disease?

A

Kayser-Fleisher ring (copper ring around the iris)

24
Q

In what disease would you notice lens dislocation that is subluxed upward?
Subluxed down?

A

Up- Marfan’s

Down- homocysteinuria

25
Q

What physical exam findings are suggestive of Noonan’s disease?

A
  1. wooly hair
  2. low hairline
  3. webbed neck
26
Q

What is arachnodactyly? What disorder is it seen in?

A

Normal finger proportion is the length of the palm.

Arachnodactyly is abnormally long fingers and the “thumb sign” suggestive of Marfan’s syndrome

27
Q

What is clindodactyly and what disorder is it suggestive of?

A

It is abnormal position of the digits and is seen in trisomy 21 with the fingers curving inward

28
Q

What is dysmorphology?

A

The diagnosis and management of congenital anatomic anomalies due to abnormal physical development
2/3 are multifactorial and only 30% are genetic

29
Q

What three pieces of information must you need to know to determine the inheritance pattern?

A
  1. examinations of others in the family
  2. biopsy specimens
  3. autopsy reports on informative family members
30
Q

Describe autosomal dominant inheritance.

A
  • It is passed vertically (every generation is affected)
  • 50% of the offspring will be affected
  • males/females are affected equally
31
Q

Describe autosomal recessive inheritance.

A
  • horizontal transmission (may skip generations)
  • low proportion of the offspring are affected (1/4)
  • higher with consanginuity
32
Q

Describe X-linked inheritance.

A
  • mothers tend to be carriers

- they pass the disease to 1/2 of their SONS

33
Q

Describe mitochondrial inheritance.

A
  • disease passed from mother to most/all of her children
34
Q

Describe anticipation.

A

A genetic disorder where the phenotype gets worse and occurs at a younger age with each generation. Ex. Huntington’s and other trinucleotide repeats

35
Q

What is imprinting?
What is an example of a disorder with paternal imprinting?
Maternal imprinting?

How is it shown on a pedigree?

A

It is when an allele is “imprinted” so it is not active.
In Angelman’s syndrome, the mother has a genetic abnormality and the father’s genes are imprinted so the children will display the disease phenotype
In Prader-Willi syndrome the father has a deleted chromosome 15 and the mothers genes are imprinted so the child will show the disease phenotype

On the pedigree the imprinted gene is marked with an x (Mx) and the disease allele is a lower case letter (m) so Mxm will show disease while mxM will not because the disease allele is imprinted

36
Q

What is variable expressivity?

A

When the severity of the illness for the same genotype differs
ex. café au lait spots on the dad, full blown neurofibromatosis on the child

37
Q

What is pleiotropy?

A

different manifestations for the same gene defect (ex. del of the same gene can cause heart defects or kidney defects)

38
Q

What is penetrance?

A

It is an all or none situation. Some people with the genetic defect will not show any disease, while others will.

39
Q

The proportion of a disease from a new mutation is inversely proportional to __________.

A

Fitness

40
Q

What are the 2 databases used to determine if a congenital anomaly is isolated or part of a syndrome or sequence?

A
  1. Gene Tests - by the NIH

2. OMIM

41
Q

What are the 4 steps to making a diagnosis of a genetic disease?

A
  1. 6 clues that point to genetic disease
  2. Determine inheritance
  3. Check OMIM and Gene Tests to see if the congenital abnormality is part of a syndrome or sequence
  4. Obtain and centralize all medical records `
42
Q

What are the 3 diagnostic tests for genetic diseases?

A
  1. screening tests for metabolic disease
  2. functional tests
  3. structural assays- like gel electrophoresis for thalassemias and sickle cell
43
Q

What is looked for in the urine for potential metabolic disorders?
In the serum?

A

Urine: mucopolysaccharides, organic acids, LCFA
Serum: AA

44
Q

What are functional tests for diagnosing genetic diseases?

A

Enzymatic assays using tissue expressing defective gene products

ex. B-glucosidase activity in Gauchers

45
Q

What are 4 methods for molecular diagnosis of a genetic disease?

A
  1. cytogenetics (FSH, karyotyping)
  2. comparative genomic hybridization (CGH)
  3. Direct detection of genetic mutation
  4. Indirect detection of mutation (Linkage)
46
Q

what is the major problem with using FSH or karyotyping to detect genetic disorders?

A

It does not detect single gene mutations or small deletions

47
Q

What is comparative genomic hybridization?

What is the drawback of this technique?

A

Chromosome microarray analysis lets you see variation in copy number (deletion, duplications) of regions of the genome
Drawback: does not detect chromosomal rearrangements like balanced or inversions where there is no net gain or loss of DNA

48
Q

What can direct detection of gene mutations identify? What is the draw back?

A

Single mutations in single genes.

You need to already know what you are looking for and the disease has to have a single gene responsible.

49
Q

How is analysis of DNA usually done for molecular identification of genetic disorders?

A

DNA is taken from lymphocytes, buccal cells, cultured cells, or biopsy.
Prenatal uses chorionic fluid

50
Q

What is mosaicism?

A

If there are somatic mutations, there may be variability in expression of some genes. Not every cell or tissue will have the exact same genetic constitution due to mutations that arose in the multicellular embryo

51
Q

Why do predictive testing for genetic disorders where there is no cure?
When should this testing be done?
What are drawbacks?

A
  1. education, employment, life experience, family planning
  2. over 18 with informed consent
  3. social stigma
52
Q

What is codominance?

What is a compound heterozygote?

A

Codominance is when alleles are expressed in heterozygous and homozygous states

Compound heterozygotes are heterozygous for 2 disease-causing mutations at the same locus

53
Q

What is contiguous gene syndrome?

A

Disease caused by deletion that includes more than one gene

54
Q

What is epigenetics?

A

factors that affect gene function without changing the sequence of the DNA (histylating, methylation, imprinting)

55
Q

What is heteroplasmy?

A

different DNA sequences in the same cell

It is seen frequently in mitochondrial disorders

56
Q

What is phenocopy?

A

when an identical phenotype is produced by defects in different genes OR a defective gene and environmental factor cause the same phenotype

Fundamentals 3- Heme (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions