Case Exam Flashcards

1
Q

G6PD Def Age of Onset and Present

A

Neonatal with hemolytic anemia and neonatal jaundice

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2
Q

G6PD Def info

A

Hereditary predisposition to hemolysis, X linked (malaria endemic areas)

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3
Q

G6PD Def Enzyme

A

G6PD is first enzyme in HMP shunt (NADPH) essential for generation of reduced glutathione used in RBCs for detox. Deficiency leads to oxidation and aggregation of intracell proteins (Heinz bodies) and rigid RBCs readily hydrolyzed. Oldest RBCs hit first

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4
Q

G6PD Def Genetics

A

X-linked. Med basin and africa. Manifests early as neonatal jaundice or acute hemolytic anemia

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5
Q

G6PD Def Triggers

A

Viral/bacterial infections, drugs, toxins. Fava Beans (contains beta-glycoside = oxidative agent). Some immuno def due to loss of oxidative burst.

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6
Q

G6PD Def Test

A

Test when old RBCs are present (not near attack or recent transfusion = false negative)

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7
Q

Familial Hypercholesterolemia Age Onset and present

A

Hetero in adult and Homo in childhood. Presents with hypercholesterolemia, atherosclerosis, Xanthema, Arcus cornea

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8
Q

Familial Hypercholesterolemia info

A

AD disorder of chol and lipid metabolism by mutations in LDLR. 1:500 white pops and accounts for 5% of cases.

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9
Q

Familial Hypercholesterolemia Protein

A

LDL-R is a transmembrane glycoprotein predominantly expressed in liver and adrenal cortex. Binds ApoB 100 (sole protein of LDL) and ApoE (protein on VLDL, chylomicrons, HDL)

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10
Q

Familial Hypercholesterolemia mutations

A

Decrease LDL endocyt efficiency leading to accumulation of plasma LDL leading to atherosclerosis by clearance of LDL by phagocytes (foam cell formation) leading to thrombus (MI and stroke)

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11
Q

Familial Hypercholesterolemia Contributing factor

A

Diet

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12
Q

Familial Hypercholesterolemia Findings

A

Hyperchol is first finding with Arcus cornea and tendon xanthomas at end of second decade

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13
Q

Familial Hypercholesterolemia Tx

A

Low fat high carb diet. Drugs = bile acid sequesters, 3-OH-3 methylglutayl CoA reductase inhib, and nicotinic acid

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14
Q

Hereditary Hemochromatosis Age of Onset and presentation

A

40-60yrs Male and after menopause for FM. Presents with fatigue, impotence, hyperpigmentation (bronzing), diabetes, cirrhosis, cardiomyopathy. Elevated serum transferrin iron sat and elevated serum Ferritin. AR.

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15
Q

Hereditary Hemochromatosis Info

A

Disease of iron overload in pts with homo or compound hetero mutations in HFE gene. Homo = Cys282Tyr mutation; hetero = Cys282Tyr/His63Asp

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16
Q

Hereditary Hemochromatosis Genetics

A

Carrier NA = 11% Cys and 27% His. Shows incomplete penetrance with Males>FM.

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17
Q

Hereditary Hemochromatosis pathway

A

Iron release from enterocytes (digest SI) and macrophages (RBC) is regulated by circulating iron response protein = Hepcidin (synth in liver and blocks iron abs when stores are full). Mutant HFE inhibs herceptin signalling leading to iron overload

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18
Q

Hereditary Hemochromatosis early s and s

A

fatigue, arthalgia, decreased libido, abd pain, increased transferrin or ferratin

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19
Q

Hereditary Hemochromatosis late s and s

A

hepatomegaly, cirrhosis, heptocell carcinoma, DM, cardiomyopathy, bronzing

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20
Q

Hereditary Hemochromatosis Tx

A

If ferratin is greater than 50 = phlembotomy

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21
Q

Hemophilia Age of onset and presentation

A

Infancy to adulthood with hemarthomses and hematomas. X linked

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22
Q

Hemophilia info

A

Hema A F8 and Hem B F9

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23
Q

Hemophilia Prevelence

A

A 1:5000 B 1:100000

24
Q

Hemophilia Pathway

A

Coagulation system consists of proteases and protein cofactors in zymogen form and mus be activated to form a clot. 8 and 9 complex together to activate 10 (9=protease, 8=cofactor)

25
Q

Hemophilia mutations in 8

A

del, insertsm invertsm pt mutations. Most common = invert deletion of carboxyl terminus of F8 and results from intrachromo recombination btwn intron 22 F8 and homologous telomeric sequences.

26
Q

Hemophilia mutations in 9

A

many different but no common. F9 Leyden = F9 variant by pt mutation in F9 promoter = svr childhood hemophilia with spont resolve at puberty

27
Q

Hemophilia presentation

A

Classically male disease (some FM with skewed X-inactivation). Clin A and B = bleeding into soft tissue, musc, joints within hours of trauma and continues for days. Severe = neonatal find with umbilical and circumcision bleeding. Moderate = once ambulatory. Mild = adult with trauma

28
Q

Hemophilia Classification

A
Severe = less than 1%
Moderate = 1-5%
Mild = 5-25%
29
Q

Hemophilia Genetics

A

New mutations for F8 invert and pt mutations due to male meiosis in pt maternal GF. Del mutations in female meiosis.

30
Q

NIDDM Age of Onset and presentation

A

Multifactorial disease with hyperglycemia, insulin resistance, obesity, acanthiosis nigricans

31
Q

NIDDM Race

A

Native Americans of Prima Arizona

32
Q

NIDDM Disease

A

Results from derangement of insulin secretion and resistance to insulin action. Response to glucose loads is inadequate with basal insulin high but not high enough to account for the hyperglycemia. Hyperglycemia desensitizes beta cells so that less insulin is released for given glucose levels, also the high insulin levels down regulate insulin receptors. Finally, glucagon is unopposed.

33
Q

NIDDM Genetics

A

Confusing. Icelandic with repeat polymorphism intron in TF TCF7L2 assoc with glucagon expression. Pro12AlA mut in PPARG in fins and mexicans = nuclear receptor that regs adipose fx. Strongly enviromental

34
Q

NIDDM Presentation

A

Usually affects middle aged with insidious onset without ketoacidosis. Hyperglycemia monitered by HBA1C lvls (7% and less = normal)

35
Q

Ornithine Transcarbamylase Def Onset and present

A

X-linked. hemizygous male with null at neonatal; hetero FM with severe illness, post partum, or never. With hyperammonia and Coma

36
Q

Ornithine Transcarbamylase Def Pathway

A

X linked disroder of urea cycle metabolism. Leads to hyperammonia and arginine becomes an essential AA. Defect causes increased glutamine and alanine (pool of N) leading to ammonia buildup (lvls >200 = brain dmg).

37
Q

Ornithine Transcarbamylase Def Present

A

Upon birth, males with with null mutation are lethargic and vomit. OTC and CPS def not detected by screenings.

38
Q

Ornithine Transcarbamylase Def Diff

A

Btwn OTC and CPS (both low citrulline) measure urine orotic acid (increased in OTC)

39
Q

Ornithine Transcarbamylase Def Tx

A

D10W, IV ammonul, Arginine HCL IV, hemodialysis. Chronic treatment is high carb diet and phenylbutyrate

40
Q

Ornithine Transcarbamylase Def Genetics

A

Male germ line mutations frequent. Males with partial OTC def have carrier daughters and no affected sons

41
Q

Tay Sachs Disease Onset and present

A

AR. Infantile to adult with neurodegeneration, retinal cherry red spots, psychosis.

42
Q

Tay Sachs Disease Enzyme

A

Infantile GM2 gangliosidosis disorder caused by def Hexosaminidase A.

43
Q

Tay Sachs Disease Ethnic

A

Ash Jews, french canadians, cajuns, amish (genetic drift)

44
Q

Tay Sachs Disease Gangliosidosis

A

ceramide oligosacc abundant in brain (cell surface) and function as receptor for glycoprotein hormones, bacterial toxins, and involved in cell diff and cell-cell interactions

45
Q

Tay Sachs Disease Hexosamidase A

A

Lysosomal enzyme with 2 subunits: Hex A (15) and B (5). Tay sachs is due to HexA mutation by removal of terminal N-acetyl galactosamine leading to accumulation. Infantile is due to 2 null mutations; adult and juvenile due to null and low residual hetero

46
Q

Breast and Ovarian Cancer mutation

A

AD. BRCA1/2 is majority of familial breast cancer. Is a TF for DNA repair and are tumor suppressors. Mutations lead to chromosome instability and frequent mutations in other TSGs.

47
Q

Breast and Ovarian Cancer two hit

A

2nd mutation cia intragene mutation or promoter hypermethylation

48
Q

Breast and Ovarian Cancer Genetics

A

Pop prevelence varies wildly (founder effect indicated). Iceland = BRCA2 999del15, Ash Jews = BRCA1 185delAG and BRCA2 617delT.

49
Q

Breast and Ovarian Cancer BRCA1

A

FM breast and ovary. 50-80% penetrance

50
Q

Breast and Ovarian Cancer BRCA2

A

FM breast and ovary; male breast and prostate. Penetrance 40% breast, 10% ovarian.

51
Q

HNPCC mutation

A

AD. Mutation in DNA mismatch repair genes. Microsatellite instability in 85%. Muts in MSH 2,6; MLH 1,3; PMS 1,2. Needs 2 hits but second hit penetrance in 80%. Perdom effect of microstellite instability is loss of TGFBR2 which allows escape of growth control.

52
Q

HNPCC Clinical

A

Develop polyps at younger ager (50) at splenic junction and ileocecal junction. Less aggressive and less chromo instab than others. Additional cancers = stomach, SI, pancreas, kidney, endometrium and ovaries.

53
Q

HNPCC confirm

A

minimal criteria of 3 members with HNPCC related tumors with at least 2 primary

54
Q

Retinoblastoma Mutation

A

AD, mut Rb1 loss of fx. 13q14. New germline = paternal; new somatic = maternal. Muts 50% at CpG. Full penetration of second hit.

55
Q

Retinoblastoma present

A

Bilaterial at 1st yr; unilateral 24-30 mnths

56
Q

Retinoblastoma secondary

A

Secondary neoplasms are osteosarcomas, sarcoma, melanomas.