BIOCHEMISTRY -GENETICS Flashcards

1
Q

CO DOMINANCE

A

Both alleles contribute to phenotype of same heterozygote

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2
Q

Blood groups, alpha 1 antitrypsin deficiency and HLA groups are examples of?

A

Co-dominance

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3
Q

Patients with same genotype and varying phenotype

A

VARIABLE EPRESSIVITY

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4
Q

PLEIOTROPY

A

One gene multiple effects

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5
Q

Increasing severity in succeeding generations is known as

A

ANTICIPATION

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6
Q

LINKAGE MUTATION

A

Tendencies of certain alleles at 2 linked loci to occur together more or less often thn

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7
Q

Trinucleotide repeat diseases is an example of?

A

Anticipation

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8
Q

MOSAICISM

A

Presence of genetically distinct cell line in the same individual

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9
Q

Types of mosaicsm

A

Somatic - mutation arises from multiple errors in fertilization and propagates through multiple organs and tissues
Gonandal - mutation in egg/sperms

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10
Q

U/L cafe au lait spots, polyostatic fibrous dysplasia and endocrinopathy - features of what syndrome

A

Mc.Cune Albright syndrome

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11
Q

Mc.Cune Albright syndrome occurs due to mutation in?

A

Gs (guanine nucleotide) binding protein

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12
Q

Albinism is an example of

A

Locus heterogeneity

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13
Q

Example of allelic heterogeneity

A

Beta thalassemia

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14
Q

mtDNA (normal + mutate DNA) passed on from mother to all children is known as

A

HETEROPLASMY

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15
Q

UNIPARENTAL DISOMY

A

2 copies from the same parent

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16
Q

How to maintain Hardy Weinberg equilibrium (p:q ratio)

A

No mutation
No natural selection
Random mating
No net migration

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17
Q

GERMLINE MOSAICISM

A

Neither parent has manifestations but siblings do

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18
Q

Examples of uniparental disomy

A

Prader Willi syndrome
Angelman syndrome
(usually results in normal progeny)

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19
Q

One gene copy silenced by methylation and other copy expressed is known as?

A

IMPRINTING

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20
Q
Hyperphagia
Obesity
Intellectual disorientation
Hypogonadism
Hypotonia seen in which syndrome?
A

PRADER WILI SYNDROME

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21
Q

Mutation or deletion of which chromosome occurs in Prader Wili syndrome

A

Chromosome 15 (paternal origin)

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22
Q

Inappropriate laughter
Seizure
Ataxia
Severe intellectual disability seen in which syndrome?

A

AngelMan syndrome

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23
Q

Which gene is silenced in AngelMan syndrome

A

UBE3A (paternal origin)

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24
Q

When paternal allele is deleted/mutated?

A

Prader Wili Syndrome

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25
Q

When maternal allele is deleted/mutated?

A

AngelMan Syndrome

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26
Q

AUTOSOMAL DOMINANT

A

Defects in structural genes. (1/2 children affected)

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27
Q

AUTOSOMAL RECESSIVE

A

With 2 heterozygous (carrier) parents (1/4-affected, 1/2-carriers, 1/4-neither)

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28
Q

X LINKED RECESSIVE

A

Sons of heterozygous mothers have 50% chances of being affected. (no male to male transmission)

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29
Q

X LINKED DOMINANT

A

Transmitted through both parents.

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30
Q

MITOCHONDRIAL INHERITANCE

A

Transmitted only through the mother. All offsprings of affected females shows signs of the disease.

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31
Q

Family history is crucial for what kind of inheritance.

A

AUTOSOMAL DOMINANT

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32
Q

Consanguineous marriages have a high risk of what kind of inheritance

A

AUTOSOMAL RECESSIVE

33
Q

Vitamin D resistant rickets are known as

A

Hypophosphatemic rickets

34
Q

What is seen in muscle biosy of Mitochondrial Myopathy (MELAS SYNDROME)

A

Ragged red fibers

35
Q

Mothers transmit 50% daughters and 50% sons,

Fathers transmit 100% daughters and no sons - seen in what kind of inheritance?

A

X LINKED DOMINANT

36
Q

Females should be homozygous to be affected by mothers for what kind of inheritance?

A

X LINKED RECESSIVE

37
Q
Achondroplasia
Familial adenomatouspolyposis
Hereditary spherocytosis
Huntington disease
NF type 1, NF type 2
Tuberous sclerosis come under what type of inheritance?
A

AUTOSOMAL DOMINANT

38
Q
Cystic fibrosis
Hemochromatosis
Kartagner syndrome
Phenyketonuria
Sickle cell anemia
Thalassemia
Wilson disease come under what kind of inheritance?
A

AUTOSOMAL RECESSIVE

39
Q

Mutation of which chromosome occurs in cystic fibrosis?

A

Chromosome 7 (CFTR gene)

40
Q

Defect in which of the following occurs in cystic fibrosis?

A
Defect in chloride channels
Increased intracellular chloride ions
Increased sodium re-absorption
 Increased H2O re-absorption
Abnormally thick mucus
41
Q

Multifactoral management of cystic fibrosis includes

A

Chest physiotherapy
Albuterol
Aerosolised dornase alpha
Hypertonic saline

Purpose - facilitates mucus clearance

42
Q

How is cystic fibrosis with Phe50S deletion managed?

A

Lumacraftor and Ivacaftor (opens chloride channels)

43
Q

______ has anti-inflammatory action and _____ slows progression - in cystic fibrosis

A

1- Azithromycin , 2-Ibuprofen

44
Q

Trisomy 21 is

A

Downs syndrome

45
Q

Trisomy 18 is

A

Edward syndrome

46
Q

Trisomy 21 is

A

Patau syndrome

47
Q
Intellectual disability
Prominent occiput
Low set ears
Congenital heart disease
Clenched fists
Rocker bottom feet seen in?
A

EDWARDS SYNDROME

48
Q
Microcephaly
Microophthalmia
Cleft lip/palate
Polydactyly
Cutis Aplasia
Polycystic kidney disease
Rocker bottom feet seen in?
A

PATAU SYNDROME

49
Q

No 1 genetic intellectual disability?

A

DOWNS SYNDROME

50
Q

No 2 genetic intellectual disability?

A

FRAGILE X SYNDROME

51
Q

Features of Downs syndrome

A

1st trimester USG - increased nuchal transluency and hypoplastic bone
Increased hCG
Increased inhibin

52
Q
Intellectual disability
Mongoloid (flat) facies
Single palmar crease
Prominent epicanthal folds
Duodenal atresia
Brucefield spots
Increased gap between first and second toes seen in?
A

DOWNS SYNDROME

53
Q

Downs syndrome is associated with which GI disorder?

A

Duodenal atresia

Hirschsprung disease

54
Q

Downs syndrome is associated with what kind of malignancy (increased risk)?

A

AML and ALL

55
Q

Downs syndrome is associated with what CNS disorder?

A

Alzheimer’s disease

56
Q

Robertsonian translocation involves chromosomes ________

A

13, 14, 15, 20, 21

57
Q

Unbalanced robertsonian translocation can result in

A

Miscarriage
Stillbirth
Chromosomal imbalance (Down syndrome, Patau syndrome)

58
Q

Deletion of which chromosome occurs in cri du chat syndorme?

A

Chromosome 15

59
Q
Microcephaly
Intellectual disability
High pitch cry
Meowing
VSD (cardiac abnormality) seen in?
A

CRI DU CHAT SYNDROME

60
Q
Elfin facies
Intellectual disability
Hypercalcemia
Extreme friendliness with strangers
CVS problems (supravalvular aortic stenosis, renal artery stenosis)
Well developed verbal skills seen in?
A

WILLIAMS SYNDROME

61
Q

Deletion of which chromosome occurs in which syndrome?

A

WILLIAMS SYNDROME

62
Q
G6PD deficiency
Hunter syndrome
Hemophilia
Lesch nyhan syndrome
Duchenne muscular dystrophy
Bruton agammaglobulinemia
A

X LINKED RECESSIVE DISORDER

63
Q

What type of mutation occurs in duchenne muscle dystrophy?

A

Frameshift mutation

64
Q

Weakness - begins in pelvic girdle
Pseudohypertrophy (fibrofatty replacement of muscles) of calf muscles
Waddling gait seen in?

A

Duchenne muscle dystrophy

65
Q

What is Gower’s sign?

Where is it seen?

A

Use of upper extremities to stand up

66
Q

Gower’s sign is seen in?

A

Polymyopathies

Duchenne muscle dystrophy

67
Q

Commonality between becker and duchenne muscular dystrophies?

A

Both are X linked disorders

68
Q

Cause of death in Duchenne muscular dystrophy

A

Dilated Cardiomyopathy

69
Q
Myotonia
Muscle wasting
Cataract
Testicular atrophy
Frontal balding
Arrhythmia seen in?
A

Myotonic type 1 muscle dystrophy

70
Q

Myotonic type 1 muscle dystrophy is what type of inheritance?

A

Autosomal dominant

71
Q
Regression in motor, verbal and cognitive abilities
Ataxia
Seizures
Growth failure
Stereotyped hand wringing seen in?
A

Rett syndrome

72
Q

Long face
Enlarged jaw
MV prolapse
Enlarged testes (post pubertal macro orchidism) seen in?

A

Fragile X syndrome

73
Q
Hungtinton disease
Myotonic dystrophy
Fragile X syndrome
Freidriche ataxia
The above are what type of diseases?
A

TRINUCLEOTIDE REPEAT EPANSION DISEASES

74
Q

Trinucleotide repeat of - Huntington disease

A

CAG

75
Q

Trinucleotide repeat of - myotonic dystrophy

A

CTG

76
Q

Trinucleotide repeat of - fragile X syndrome

A

CGG

77
Q

Trinucleotide repeat of - Freidriche ataxia

A

GAA

78
Q

Hallmark of X linked disorders

A

Absence of Father to Son transmission