Genetic diseases I Flashcards Preview

Path Section II exam > Genetic diseases I > Flashcards

Flashcards in Genetic diseases I Deck (102):
1

Derived from ones parents and transmitted through the gametes

Hereditary

2

Origin of defect

Hereditary

3

How many generations have had defect; can be expressed or not expressed

Familial

4

Genetic disease that occurs sporadically

Familial

5

Any abnormality present at birth

Congenital

6

mutation of a single gene of large effect

mendelian disorder

7

disorders with multiple genes as well environmental influences

Complex Multigenic Disorder

8

Disorders with multifactorial inheritance

Complex Multigenic Disorders

9

disorder where phenotypic expression is related to the combined effects of environmental influences and multiple genes of small effects (polygenic inheritance )

Complex multigenic disorders

10

diseases arising from chromosomal aberrations that are identifiable on karyotype

Cytogenic Disorders (Chromosomal Disorders)

11

ingle-gene Disorders with Atypical Patterns of Inheritance

1. single gene defects that do not follow Mendelian patterns of inheritance

12

What are examples of single gene disorders w/ atypical patterns of inheritance?

a. Triplet repeat mutations and mutations in mitochondrial genes
b. Disorder with genomic imprinting – transmission is influenced by epigenetic phenomena

13

A karyotype is constructed from photographic images of patient cells in

Metaphase

14

What stain is widely used as the G banding technique?

Giemsa stain

15

Karyotypes can be performed on children and adults by culturing what types of cells?

Lymphocytes from the peripheral blood

16

Karyotypes can be performed on fetuses by culture of what cells?

Fetal fibroblasts from amniotic fluid or placental sampling

17

primary constriction

centromere

18

Short arm=

up arm-"p" for petit

19

Long arm

down arm "q"

20

Satellite

at ends of p

21

“p” and “q” arms are of equal length.

Metacentric

22

“p” arm is shorter than “q” arm.

Submetacentric

23

“p” arms are very short and have satellites

Acrocentric

24

How is a karyotype arranged?

Metacentric-> subcentric-> acrosentric->sex-chromosomes (acrocentric)

25

When is the earliest amniocentesis can be performed?

15 weeks

26

Which test can be performed at 10 weeks?

Chorionic villi sample

27

any exact multiple of the haploid number

Euploid

28

multiples of the haploid number beyond 2n, such as 3n, 4n, 5n, etc.

Polyploid

29

a. any number of chromosomes that is not an exact multiple of n
Examples – (n + 1), (n - 1), (2n + 1), (2n - 1)

Aneuploidy

30

defined as two or more karyotypic populations of cells in the same individual. Occurs more commonly involving the sex chromosomes.

Mosaicism

31

What are the 2 types of translocations?

1. Balanced reciprocal translocation
2.Robertsonian translocation or centric fusion

32

1) fragments are exchanged between two chromosomes and no genetic material is lost.

Balanced reciprocal translocation

33

reciprocal translocation that always occurs between two acrocentric chromosomes

Robertsonian translocation or centric fusion

34

in which translocation do we ALWAYS get loss of genetic material?

Robertsonian translocation (centric fusion)

35

a. Centromere divides transversely so that the two short arms are paired and the two long arms are paired.

Isochromosomes

36

Loss of a portion of a chromosome

deletion

37

What is worse having extra chromosomes or missing chromosomes?

missing

38

1) One chromosome breaks, then the broken segment makes a complete turnaround and reattaches to the original chromosome.

inversions

39

what are the 2 patterns of inversion?

Paracentric and pericentric

40

have both breaks on the same side

paracentric

41

have breaks on either side of the centromere

pericentric

42

which chromosome aberrations have structural abnormalities?

Translocations
isochromosomes
deletions
inversions
ring chromosomes

43

which chromosome aberrations have numerical abnormalities?

Polyploid
aneuploidy
mosaicism

44

2 or more distinct karyotypic cell populations in the same individual

Mosaicism

45

mosaicism is an abnormality that occurs due to what?

Nondisjunction

46

deletion that occurs at both ends of a single chromosome, then damaged ends fuse

Ring chromosome

47

what are abnormalities that create re-arranged material?

Translocations and inversions

48

Abnormalities involving ____are generally more severe than defects involving _____________

Autosomes
sex chromosomes

49

a missing ______ is not compatible with life

autosome

50

how do most cytogenic disorders arise?

arise De Novo in the gametes

51

disorder is neither in the parental line nor is it familial

cytogenic disorder

52

chromosomal abnormality arises during gametogenesis

cytogenic disorders

53

What are the cytogenic disorders involving autosomes?

Trisomy 21- Down syndrome
Trisomy 18- Edwards syndrome
Trisomy 13- Patau syndrome

54

incidence 1: 1700 live births

Down syndrome

55

47XX +21 or 47XY+21

down syndrome

56

% of down syndrome caused by translocation?

4%

57

% of down syndrome mosaics

1%

58

46XX/47 XX +21

down syndrome mosaics

59

what tests do you use to diagnose Down syndrome?

First trimester screening test and Karyotyping

60

identifies polymorphicgenetic markers of fetal free DNA in maternal blood

First trimester screening test

61

when is the first trimester screening test done?

11-13 weeks gestation

62

which disorder has horizontal palmar crease/ simian crease?

down syndrome

63

which disorder has hypotonia?

down syndrome

64

which disorder has congenital heart defects?
e.g.atrial septal defect

down syndrome

65

which disorder has high risk for developing Alzheimer's?

Down syndrome

66

which disorder has late face and epicentral folds?

down syndrome

67

what are the most common causes of death for down syndrome?

-heart defects
-infections
- leukemia

68

what is the median life expectancy for DS?

60 years old

69

which disorder has predisposition for autoimmune thyroid disease-> hypothyroidism?

down syndrome

70

incidence 1:8,000 live births

edwards syndrome

71

47,XY,+18 or 47,XX,+18

edwards syndrome

72

which disorder displays prominent occiput?

Edwards syndrome

73

which disorder displays micrognathia?

Edwards syndrome

74

which disorder displays hypertonicity?

Edwards syndrome

75

which disorder displays horse shoe kidney?

Edwards syndrome

76

which disorder displays crossed fingers

Edwards syndrome

77

which natural position in edwards syndrome persists in death?

crossed fingers

78

which disorders display rocker bottom feet?

edwards and patau

79

Incidence 1:15,000live births

Patau syndrome

80

47,XX,+13 or 47,XY,+13

Patau syndrome

81

which disorder displays microcephaly?

Patau syndrome

82

which disorder displays micropthalmia?

Patau syndrome

83

which disorder presents with cleft lip and cleft palate?

Patau syndrome

84

which disorder presents with polydactyly

Patau syndrome

85

what are the cytogenic disorders involving sex chromosomes?

Klinefelter syndrome
Turners syndrome

86

incidence 1:1,000 to 1: 1500 live male births

Kleinfelter syndrome

87

up to 15% mosaics

Kleinfelter syndrome

88

which syndromes have hypogonadism?

Kleinfelter syndrome and turners syndrome

89

Small testes
low testosterone
elevated urine are clinical features of what disorder?

Kleinfelter syndrome

90

breast development in men

gynecomastia inKleinfelter syndrome

91

Elongated body appearance -long legs particularly in femur

Kleinfelter syndrome

92

mild decreased intelligence relative to other family members

Kleinfelter syndrome

93

increased risk for breast cancer, extragonadal germ cell tumors and autoimmune disease

Kleinfelter syndrome

94

incidence 1: 2,500-1:2,000 live female births

Turners syndrome

95

Monosomy-only one sex chromosome

Turners syndrome

96

45X

Turners syndrome

97

% mosaics in turners syndrome?

43%

98

possible problems with cystic hydromas?

Turners syndrome

99

which syndrome manifest short stature?

Turners syndrome

100

Webbed neck and low posterior hair line

Turners syndrome

101

broad (shield) chest

Turners syndrome

102

coartaction of aorta

Turners syndrome