Brainscape's Knowledge GenomeTM

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


See full index

Genetics Block 2 > Diseases and Mutations > Flashcards

Diseases and Mutations Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Chromsome for NF1

A

17

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
  • Mode of Inheritance: Autosomal Dominant
  • Defective gene:- loss of function mutations of NF1 gene, neurofibromin
  • chromosome 17
  • disorder of nervous system
  • Phenotype: eyes (lisch nodules/multiple iris hamartomas), skeleton, skin (café au lait spots), benign and malignant tumors of nervous system,
  • Pleiotropic - variable expressivity -allelic heterogeneity - Signs develop during childhood
  • Affects tumor suppressor protein Ras GTPase
A

Neurofibromatosis (NF1)

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

Chromosome for Achondroplasia?

A

4

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

Defective gene for Achondroplasia?

A

FGFR3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  • Mode of Inheritance: Autosomal Dominant, gain of function
  • Defective gene: Mutation in fibroblast growth factor receptor 3 gene (FGFR3)
  • Chromosome 4
  • Most common mutation is in Guanine at position 1,138
  • Phenotype: Small stature, short limbs, large head, low nasal bridge, prominent forehead, lumbar lordosis
  • new gain-of-function mutation
A

Achondroplasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
  • Mode of Inheritance: Autosomal Dominant
  • Cutaneous xanthomas, premature coronary artery disease, high blood cholesterol levels
  • mutation in Low-Density Lipoprotein (LDL) receptor
A

Familial Hyperchoesterolemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  • Mode of Inheritance: Autosomal Dominant
  • Defective Gene: mutation in PKD1 (chromosome 16) and PKD2 (chromosome 4)
  • cyst development requires “two-hit” mechanism, both alleles of either PKD1 or PKD2 must lose function for cysts to form
  • Progressive renal failure, renal and hepatic cysts, intracranial saccular aneurysms, mitral valve prolapse, colonic diverticula
A

Polycystic Kidney Disease

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

Chromsome for Marfan’s

A

15

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Defective gene for Marfan’s?

A

FBN1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
  • Mode of Inheritance: Autosomal Dominant
  • Phenotype: Disproportionate tall stature and skeletal abnormalities, hypermobile joints, ocular abnormalities (detached lenses), cardiovascular diseases, aortic rupture
  • Defective gene: Mutation in the FBN1 gene coding for fibrillin-1 - chromosome 15
A

Marfan’s Syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  • Mode of Inheritance: X-linked Recessive
  • Phenotype: blood fails to clot normally, bleeding into soft tissues, muscles, and weight bearing joints
  • Defective gene: Due to deficiency of factor VIII (F8) gene
  • incidence is 1 in 5000-10000 newborn males
A

Hemophilia A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
  • Mode of Inheritance: X-linked Recessive
  • Phenotype: blood fails to clot normally, bleeding into soft tissues, muscles, and weight bearing joints
  • Defective gene: Due to deficiency in factor IX (F9) gene
  • incidence is rare at 1 in 100000
A

Hemophilia B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  • Mode of Inheritance: X-linked recessive
  • Phenotype: progressive myopathy
  • Defective gene: deletion of dystrophin gene
  • Frequently due to de novo mutations of large deletions (60-65%) and duplications, or small deletions, insertions or nucleotide changes
A

Duchenne Muscular Dystrophy (DMD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  • Mode of Inheritance: X-linked Dominant
  • normal prenatal and neonatal growth and development followed by rapid onset of neurological symptoms and loss of milestones between 6 mos and 18 mos of age
  • Phenotype: spastic, ataxic, autistic features, irritable behavior, purposeless flapping movements, seizures (50%)
  • patients become severely retarded
  • Defective gene: mutation in MECP2, methyl-CpG-binding protein 2, which mediates transcriptional silencing
A

Rett Syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  • Defective gene: mutation in MECP2, methyl-CpG-binding protein 2, which mediates transcriptional silencing
A

Rett Syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Chromsome for Huntington’s

A

4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q
  • Mode of inheritance: Autosomal Dominant
  • Progressive disorder: motor: chorea and dystonia (involuntary movements and spasms), cognitive, and psychiatric changes
  • Age of onset about 35-44 yrs
  • Defective gene:Caused by an expanded polyglutamin repeat in the protein Huntington (Htt) causing protein to aggregate and damage neurons
  • Expansion of CAG trinucleotide repeats in Htt
  • Chromosome 4p16.3
  • CAG codes for glutamine, normal 40 CAG repeats
A

Huntington Disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q
  • Defective gene: Caused by abnormal CGG repeat >200 leading to hyper-methylation of 5’ UTR and decreased FMR1 (Fragile X Mental Retardation 1) expression
A

Fragile X Syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q
  • Mode of inheritance: X-linked Dominant
  • Phenotype: Big ears, big upper jaw, mental retardation and macroorchidism and deep plantar creases
  • Defective gene: Caused by abnormal CGG repeat >200 leading to hyper-methylation of 5’ UTR and decreased FMR1 (Fragile X Mental Retardation 1) expression
A

Fragile X Syndrome

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

Chromsome for Myotonic Dystrophy-

A

19

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
  • Defective gene: DMPK (dystrophia myotonica-protein kinase) gene undergoes repeat expansion of CUG triplet in the 3’ UTR of the mRNA
A

Myotonic Dystrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q
  • Mode of inheritance: Autosomal Dominant
  • notorious lack of penetrance, pleiotropy, and variable expression in clinical severity and age of onset
  • phenotype: distal weakness and wasting, facial weakness, myotonia, cataracts, heart issues, GI issues, respiratory muscle issues, mental retardation, diabetes, hypogonadism
  • Defective gene: DMPK (dystrophia myotonica-protein kinase) gene undergoes repeat expansion of CUG triplet in the 3’ UTR of the mRNA
  • Chromosome 19
A

Myotonic Dystrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Chromsome for Friedreich Ataxis

A

9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
  • Defective gene: due to GAA repeat expansion of 100-1,200 in the first intron of Frataxin gene impairing transcriptional elongation
A

Friedreich Ataxia (FRDA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q
  • Mode of Inheritance: Autosomal recessive
  • incoordination of limb movements, difficulty with speech, diminished/absent tendon reflexes, cardiomyopathy, scoliosis, foot deformities
  • Defective gene: due to GAA repeat expansion of 100-1,200 in the first intron of Frataxin gene impairing transcriptional elongation
  • chromosome 9
A

Friedreich Ataxia (FRDA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q
  • Defective gene: mutations in 1 or more of RET (receptor tyrosine kinase), RET ligand GDNF (glial cell line-derived neurotrophic factor), EDNRB (endothelin B receptor) and its ligand endothelin3 (EDN3)
A

Hirschsprung Disease (HSCR)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q
  • Mode of possible Inheritance: Autosomal Dominant (LOF), recessive, and multifactorial
  • Complete absence of some or all of the intrinsic ganglion cells in the colon
  • severe constipation, megacolon
  • Defective gene: mutations in 1 or more of RET (receptor tyrosine kinase), RET ligand GDNF (glial cell line-derived neurotrophic factor), EDNRB (endothelin B receptor) and its ligand endothelin3 (EDN3)
  • chromosome 10q11.2, 3p21, and 19q12
A

Hirschsprung Disease (HSCR)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q
  • Autoimmune destruction of islet Beta cells in pancreas
  • Loss of insulin production
  • usually manifests in children or adolescence
  • polydipsia, polyuria
  • a genetic factor is MHC class II locus (HLA-DR3 or HLA-DR4) - DQB10201 allele (DR3) or DQB10302 allele (DR4)
A

Type 1 Diabetes Mellitus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q
  • Late onset after age 60
  • protein misfolding of Amyloid Precursor Protein (APP) creating neurotoxic peptide (AB1-42)
  • loss of memory, dementia, mood swings, B-amyloid neuritic plaques, neurofibrillary tangles, abnormal cleavage of amyloid precursor protein by alpha, beta, gamma secretases
  • Tau protein normally organizes microtubules but abnormal post-translation hyperphosphorylation causes tangles
  • ApoE (apolipoprotein E-involved in cearing LDL from the liver) gene disfunction [chromosome 19] e4 allele
A

Alzheimer Disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

-failure of fusion of the arches of the vertebrae with varying degrees of severity, typically in lumbar region

A

Spina bifida

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q
  • most common congenital malformation
  • failure of fusion of the frontal process with maxillary process
  • maternal smoking is a known risk factor
A

Cleft Lip and Palate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q
  • genetic and environmental factors
  • males have a higher risk
  • hypertension, obesity, and diabetes mellitus are risk factors
  • environment factors are diet, physical activity, and smoking
  • obstruction of arteries feeding the heart
  • kills about 450,000 people in the US yearly
A

Coronary Artery Disease (CAD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q
  • symptoms include fever, difficulty breathing, productive cough with greenish sputum
  • history of recurrent lower respiratory tract infections and foul smelling diarrhea
  • mild cyanosis, tachycardia, clubbing of fingernails
  • high sweat sodium and chloride concentrations in sweat test
  • Defective gene: Caused by autosomal recessive mutation in CFTR gene (deltaF508): a deletion of phenylalanine at position 508 leading to inability of protein to escape the ER - inability of cells to transport chloride and water to body secretions (lung, pancreas, sweat glands)
  • Modifier genes: Mannose-Binding Lectin (MBL2) - plasma protein in innate immune system aiding in destruction of pathogenic organisms Transforming Growth Factor B1 (TGFB1) - promotes lung scarring and fibrosis after inflammation
  • chromosome 7q31-7q32
A

Cystic Fibrosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q
  • IgG antibodies produced by the mother Rh- mother pass through the placenta and attack the RBCs of the Rh+ fetus causing hemolysis
  • Treatment by injection of anti-Rh antibodies (Rho(D) immune globulin or RhoGAM) to destroy the fetal erythrocytes in her blood
A

Hemolytic Disease of the Newborn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q
  • autosomal recessive
  • iron overload
  • mutant HFE gene in linkage disequilibrium with HLA-A*0301
A

Hemochromatosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

I = q^2

A

Autosomal Recessive (HWeq)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

2q = I

A

Autosomal Dominant (HWeq)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

I = q I = affected males

A

X-linked Recessive (HWeq)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q
  • autosomal recessive
  • post-axial polydactyly, congenital heart defects, prenatal tooth eruption, fingernail dysplasia, short-limbed dwarfism, short ribs, cleft palate, malformation of the wrist bones
A

Ellis-van Creveld (EVC) syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q
  • loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. As a result of the loss of genetic variation, the new population may be distinctively different, both genetically and phenotypically, from the parent population from which it is derived.
A

Founder Effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q
  • chronic inflammatory disease of the gastrointestinal tract - primarily adolescents and young adults
  • Crohn disease (IBD1 locus linkage) and ulcerative colitis are 2 major categories
  • NOD2 protein (nucleotide-binding oligomerization domain containing 2) gene- binds to gram-negative bacterial cell walls and participates in the inflammatory response to bacteria by activating the NF-κB transcription factor in mononuclear leukocytes; variants reduced ability of NOD2 to activate NF-κB leading to an abnormal inflammatory response
A

Inflammatory Bowel Disease (IBD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q
  • nocturnal abdominal pain, diarrhea, gradual weight loss - usually ileum and ascending colon
  • granulomatous inflammation causing narrowing and scarring - arthritis of spine and joints, uveitis, skin issues, hypercoagulability, erythema nodosum
  • treatment by corticosteroids, anti-inflammatory meds, antibiotics, immune modulators -presents in adolescence or young adulthood
A

Crohn Disease (CD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q
  • Defective gene: missense mutation in the 6th codon of the beta globin gene
  • glutamate to valine missense
  • hemoglobin with 2 normal alpha chains and 2 mutant beta chains (HbS)
  • causes HbS hemoglobin to polymerize under deoxygenated condtions - anemia, failure to thrive, splenomegaly, repeated infections, and dactylitis
A

Sickle Cell Anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q
  • Mode of Anticancer: Autosomal Dominant
  • unstable hemoglobin with substitution of conserved phenylalanine with serine
  • heme drops out of pocket, hemoglobin precipitates, low oxygen affinity, cyanosis
A

Hb Hammersmith

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q
  • Mode of Inheritance: autosomal recessive
  • b-chain has a substitution at sixth amino acid from glutamic acid to lysine
  • less soluble than Hb A, tends to crystallize in RBCs causing hemolysis
A

Hb C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q
  • Mode of Inheritance: Autosomal Dominant
  • His92 to Tyr - oxidized heme iron incapable of reversible oxygenation - cyanotic
A

Hb Hyde Park (a Hb M)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q
  • Mode of Inheritance: Autosomal Dominant
  • Asp99 to Asn - locks hemoglobin into relaxed structure with high oxygen affinity - polycythemia
A

Hb Kempsey

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q
  • disorder of alpha-globin production (chromosome 16)
  • Hydrops fetalis- no alpha globin chains with high levels of Hb Bart’s (gamma globin tetramer = ineffective)
  • Hb H - (4 beta subunits) loss of 3 alpha globin genes - severe anemia, splenomegaly - alpha - thalassemia trait - 2 functional alpha genes
  • mild anemia and microcytosis - ZF deletion of alpha1-globin gene at 3’ end of LUC7L gene leading to antisense alpha2-globin RNA causing hypermethylation and thus gene silencing
A

alpha - Thalassemia disorders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q
  • single-base pair substitution/point mutation
  • severe anemia (Cooley’s anemia/thalassemia major) in B0 - B0 = no Hb A present - B+ = 10 to 30% Hb A detectable - hypochromic anemia, microcytic RBCs in B+ - chipmunk face
A

beta - Thalassemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

a benign condition because the remaining g gene or genes remain active after birth and Hb F (a2g2) compensates for the absence of Hb A

A

Hereditary Persistence of Fetal Hemoglobin (HPFH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q
  • Autosomal Recessive
  • (GM2gangliosidosis)-neurological degenerative disorder that develops at 6 months of age
  • Has increased frequency in certain genetic isolates such as Ashkenazi Jews in North America where the carrier frequency is 1 in 30.
A

Tay Sach’s Disease

52
Q
  • Impairs the production of
  • Mostly due to point mutations in the β-globin
  • Lead to a decrease in the abundance of b-globin mRNA -Nonfunctional mRNAs
  • have premature stop codons (Gln39Stop) or single-base pair deletion at codon 16 → cause b0 thalassemia -Capping effect -Polyadenylation defect
A

Simple b-Thalassemia

53
Q
  • Locus Heterogeneity -Digenic inheritance
  • Disease phenotype requires that the affected individual is heterozygous for two rare mutations in two different unlinked genes without the influence of any known environmental factors
  • Mutant in both: Rom1 and Peripherin
  • Mutations in 43 different loci
  • Phenotype requires that the affected individual is heterozygous for 2 rare mutations in 2 different unlinked genes without the influence of any known environmental factors
  • Having the two mutated genes is sufficient to cross a threshold of cell damage, photoreceptor death, loss of vision
  • Hetero patients for both the Rom1 and Peripherinphotoreceptor membrane proteins will develop the disease
A

Retinitis Pigmentosa

54
Q
  • Missense mutation in Factor V Leiden, FVL, at position 506: Arg→Gln(protein more stable)
  • Missense: A.A. → Different Amino Acid -Mutations in 3’ UTR 20210 G>A, stabilizes the mRNA (**Purine Transition) AND Increase in Oral Contraceptives affect Prothrombin -Oral Contraceptives affect factor 10 -Hyper-coagulable state: venous or arterial clots form inappropriately and cause life-threatening complications.
  • mutations are also involved with deep venous thrombosis of the lower extremities seen in 1 per 1,000 individuals per year with mortality of up to 10% primarily due to pulmonary embolus, depending on age and the presence of other medical conditions
A

Idiopathic Cerebral Vein Thrombosis

55
Q

the forebrain, overlying meninges, vault of skull and skin are absent → most infants are still born and 2/3 of affected infants are female

A

anencephaly

56
Q

gain of function mutation that results in unregulated hyperfunction of the kinase which leads to dominantly inherited cancer of the thyroid and adrenal glands

-chromosome 10 -RET gene

A

Multiple endocrine neoplasia (MEN) type 2a and 2b

57
Q

-thought to regulate several intracellular processes, including activating Ras GTPase, thereby controlling cellular proliferation and acting as a tumor suppressor -it is widely expressed in almost all tissues, but most abundantly in the brain, spinal cord, and peripheral nervous system

A

Neurofibromin

58
Q

-pseudoautosomal inheritance -dominantly inherited skeletal dysplasia with a disproportionate short stature and deformity of the forearm -caused by mutation in the SHOX gene (which escapes x-inactivation)

A

Dyschondrosteosis

59
Q

a condition marked by the deposit of bile pigments of the brain and spinal cord by degeneration of nerve cells that occurs usually in infants as part of the syndrome of erythroblastosis fetalis

A

Kernicterus

60
Q

an inflammatory disorder that involves tender, red bumps under the skin

A

erythema nodosum

61
Q

a condition that causes large, painful sores to develop on skin

A

pyoderma gangrenosum

62
Q

chronic liver disease caused by progressive inflammation ad scarring of the bile ducts of the liver. the inflammation impedes bile flow to the gut, which can lead to cirrhosis, liver failure and cancer.

A

primary sclerosing cholangitis

63
Q

sickle cell hemoglobin due to single missense nucleotide substitution changes the codon of the 6th amino acid from glutamic acid to valine

A

Hb S

64
Q

mode of inheritance for Neurofibromatosis (NF1)

A

Autosomal Dominant

65
Q

mode of inheritance for Achondroplasia

A

Autosomal Dominant, gain of function

66
Q

mode of inheritance for Familial Hyperchoesterolemia

A

autosomal Dominant

67
Q

mode of inheritance for Polycystic Kidney Disease

A
  • Autosomal Dominant
68
Q

mode of inheritance for Marfan’s Syndrome

A

-Autosomal Dominant

69
Q

mode of inheritance for Hemophilia A

A

-X-linked Recessive -

70
Q

mode of inheritance for Hemophilia B

A
  • X-linked Recessive -
71
Q

mode of inheritance for Duchenne Muscular Dystrophy (DMD)

A

X-linked recessive -

72
Q

mode of inheritance for Rett Syndrome

A

:X-linked Dominant -

73
Q

mode of inheritance for Huntington Disease

A
  • Autosomal Dominant
74
Q

mode of inheritance for Fragile X Syndrome

A

X-linked Dominant -

75
Q

mode of inheritance for Myotonic Dystrophy

A

Autosomal Dominant -

76
Q

mode of inheritance for Friedreich Ataxia (FRDA)

A

-Autosomal recessive

77
Q

Hemolytic Disease of the Newborn

A
  • IgG antibodies produced by the mother Rh- mother pass through the placenta and attack the RBCs of the Rh+ fetus causing hemolysis - Treatment by injection of anti-Rh antibodies (Rho(D) immune globulin or RhoGAM) to destroy the fetal erythrocytes in her blood
78
Q

Hemochromatosis

A
  • autosomal recessive - iron overload -mutant HFE gene in linkage disequilibrium with HLA-A*0301
79
Q

Autosomal Recessive (HWeq)

A

I = q^2

80
Q

Autosomal Dominant (HWeq)

A

2q = I

81
Q

X-linked Recessive (HWeq)

A

I = q I = affected males

82
Q

mode of inheritance for Ellis-van Creveld (EVC) syndrome

A
  • autosomal recessive -
83
Q

mode of inheritance for Hb Hammersmith

A

-Autosomal Dominant

84
Q

mode of inheritance for Hb C

A
  • autosomal recessive -
85
Q

mode of inheritance for Hb Hyde Park (a Hb M)

A

-Autosomal Dominant -

86
Q

mode of inheritance for Hb Kempsey

A

Autosomal Dominant

87
Q

mode of inheritance for Tay Sach’s Disease

A

-Autosomal Recessive

88
Q

Defective Gene: FGRF3?

A

Acondroplasia

89
Q

Defective Gene: FBN1?

A

Marfan’s

90
Q

Factor 8?

A

Hemophilia A

91
Q

Factor 9?

A

Hemophilia B

92
Q

Expansion repeats in Huntington’s?

A

Expansion of CAG trinucleotide repeats

93
Q

Repeat Expansion for Myotinic Dystrophy?

A

undergoes repeat expansion of CUG triplet in the 3’ UTR of the mRNA

94
Q

Repeat Expansion for Friedrich Ataxia?

A

GAA repeat expansion of 100-1,200 in the first intron of Frataxin gene impairing transcriptional elongation

95
Q

What is the mode of inheritance for Sickle Cell Anemia?

A

AR

96
Q

What causes the sickle cell hemoglobin?

A

a single missense nucleotide substitution change in the codon of the 6th amino acid from glutamic acid -> valine

97
Q

anemia, failure to thrive, splenomegaly leading to autosplenectomy, dactylitis

A

sickle cell

98
Q

B-chain has substitution at 6th amino acid from glutamic acid-> lysine

-less soluble than HbA and tends to crystallize in RBCs causling a mild hemolytic disorder

A

Hb C

99
Q

unstable hemoglobin with substitution of the Phe42 with Ser, allowing heme to drop out of the pocket, causing hemoglobin to precipate

-low oxygen affinity leads to cyanosis

A

Hb Hammersmith

100
Q

His92Tyr

  • b-chain methemoglobin wehre oxidized heme iron is incapcable of reversible oxygenation
  • cyanosis
A

Hb Hyde Park

101
Q

Aps99Asn

-mutation “locks” hemoglobin into the relaxed structure with high oxygen affinity causing polycythemia (increase in RBC #)

A

Hb Kempsey

102
Q

What are Heinz bodies, how do they form, and what do they do?

A

In Thalaseemias, the chin produced at the normal rate is in excess and eventually precipitates to form these occlusions, which damage the membrane and cause premature RBC destruction.

103
Q

all 4 a-globin chains are absent

  • high levels of Hb Barts
  • severe intrauterine hypoxia, stillbirth ot neonatal death
A

Hydrops fetalis

104
Q

homotetrameric with g4 composition is an ineffective oxygen carrier, primarily seen among Southeast Asians

A

Hb Barts

105
Q

loss of 3 a-genes

-moderately severe anemia and splenomegaly

A

Hb H

106
Q

functional a genes (a-/a- or aa/–)

mild anemia, microcytosis

A

a-thalassemia trait two

107
Q

What causes the most common form of a-thalasseia?

A

deletions of one of the two a-globin genes on a chromosome

108
Q

What can cause the deletion of tha a-globin gene?

A

misalignment, homologous pairing, and recombination between the a1 gene on one chromosome and the a2 gene on the homologous chromosome

109
Q

the mutation associated with the 13kb HpaI fragment of the sickle cell gene originated where?

A

West Africa

110
Q

the mutation associated with the 7.6kb HpaI fragment of the sickle cell gene originated where?

A

it arose separately and probably had multiple origins

111
Q

What does the Zf deletion remove?

A

the a1-globin gene and the 3’end of the LUC7L gene, including its termiantion site

112
Q

What does the ZF deletion lead to?

A

formation of a mutant hybrid RNA composed of the LUC7L mRNA and an antisense a2-globin RNA

113
Q

the antisense a1-globin RNA formed in the ZF deletion contains sequences that correspond to what?

A

a2-globin CPG island

114
Q

the antisense transcription formed in the ZF deletion is consistently associated with what?

A

methylation of the q2-globin CPG island and silencing of the a2-globin gene expression

115
Q

What is β-thalassemia usually due to?

A

single-base pair substitution (point mutation), not deletions

116
Q

individuals with 2β-thalassemia alleles

-severe anemia and need ligelong medical management

A

Thalassemia Major/Cooley’s anemia

117
Q

no HbA present

A

β0 thalassemia

118
Q

only 10-30% of HbA detected

A

β+ thalassemia

119
Q

seen in carriers of one β-thalassemia allele

-hypochromic, microcytic RBCs, slight anemia

A

thalassemia minor

120
Q

how is β-thalassemia treated?

A

bone marrow transplant

121
Q

any type og anemai in which the red blood cells are paler than normal

A

hypochromic

122
Q

what do the classic feature of β-thalassemia of prominent cheebones result from?

A

expansion of the marrow cavity in the bones of the skll and face

123
Q

~80% of untreated β-thalassemia patients die by what age?

A

5 years

124
Q

impairs the production of β-globin alone

results in many differnt types of molecular abnormalitiels, predomianntly point mutaitons - most lead to a decrease in β-globin gene

A

Simple β-thalassemia

125
Q

premature stop codons due to a single nucleotide substititution (Gln39Stop) or single base pair deletion at codon 16 that can lead to B0 thalassemia

A

Nonfunctional mRNAs

126
Q

What is the capping defect?

A

patient had an A->C transversion

127
Q

what is the polyadenlyation defect

A

signal AAUAAA, patient had substitution to AACAAA

Genetics Block 2 (6 decks)

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