Biochemistry Flashcards
Major cause of AR SCID
Def of adenosine deaminase
Lesch Nyhan Syndrome
Gout, angry, MR, self mutilation, orange sand in diaper
Tx: allopurinol or febuxostat
What is defective in xeroderma pigmentosum?
Nucleotide excision repair - can’t fix pyrimidine dimers from UV light - in G1 phase
= increased risk skin CA
What is defective in Lynch syndrome?
Mismatch repair in G2 phase
What is mutated in ataxia telangiectasia?
Nonhomologous end joining to fix ds breaks
What blocks 30S protein synthesis?
Aminoglycosides
Tetracyclines - block from getting to A site
What drugs prevent protein synthesis at 50S?
Clindamycin Macrolides Streptogranines Chrolamphenicol Linezolid
GFAP
Stains for neuroglia
Good for astrocytoma, glioblastoma
Desmin
Stains muscle
Good for tumors - rhabdomyosarcoma
Drugs that work on microtubules
Mebendazole - anti helminth Griseofulvin - antifungal Colchicine - gout Vincristine/Vinblastine - CA Paclitaxel - CA
Type I collagen
Bone, skin, tendon
Type II collagen
Cartilage
Type III collagen
Reticulin - skin, blood vessels, fetal, granulation
– Ehlers Danlos
Type IV collagen
Basement membrane
- targeted by autoabs in Goodpasture
- Alport syn
Defective in Ehlers Danlos?
Type III Collagen
Defective in Alport syndrome?
Type IV collagen
Mut in ALS?
SOD1
Superoxide dismutase
Brushfield spots
Downs - while fibrotic speckles on iris
Downs associations:
Hirschsprung Duodenal atresia Early Alzheimer's CA - baby AML CA - 3-7 y ALL Quad screen: all down except hi -decreased aFP, estriol - increased B-hcg, inhibin A
Trisomy 18
Edward - Edward Cullen stuck at 18
Horseshoe kidney, rocker bottom feet, overlap fingers
Quad screen - all 4 decreased
Trisomy 13
Patau - 1 and 3 on side - extra finger and cleft lip
holoprosencephaly
Cri du chat
5 little short cats with small heads crying over a broken heart
Deletion short arm of chr 5, hypo plastic larynx
VSD mc
Klinefelters
Inc. FSH, LH Dec. T guys are kinky, too much seX Osteoporisis Increased risk BCA, testicular CA
4 causes of Hydrops Fetalis
Parvo B19
Rh- incomp
a-Thal
Turner syn
Turners
Shorty missing x - Shox - homeobox gene
cystic hygroma - web neck
Tay Sachs
Tay is 15 yrs old, walking through the woods - takes cherries and throws through the window of an old house. witch comes out, reaches into sach and puts a hex on him. Only 2 cars, 2 GM cars.
Def of hexosaminodase A, accumulates GM2 ganglioside
EM: distended lysosomes with whorls (like car wheel)
Retina - cherry red spot
Niemann Pick
Neimann picks his nose and sphings it at a zebra with stripes
Def in sphingomyelinase, sphingomyelin accumulates - brain, retina, Macrophages = big organs
Chr 11 that look like stripes on zebra
Gaucher dz
MC Chr 1 Def of glucocerebrosidase, glucocerebroside accumulates - Macro Gaucher cell - sinusoids filled with RBC Bone - erlenmeyer flask deformity
Erlenmeyer bones
Gaucher dz
Osteopetrosis
Pompe Dz
Glycogen in lysosome - PAS+
a-1-a4-glucosidase
aka acid maltose
Mucopolysaccharidosis
GAGs accumulate –> HS, DS, CS (chondroiton sulfate)
1st in macro -> HSM, fibroblasts accumulate = cloudy cornea
MC: Hurler
Hunter
Hurler dz
Hurling is worse than hunting
Spiderman villan Gargoyle throwing pumpkins full of PAS+
Misses spiderman = cloudy body - cornea, bone abnl, CTS
rides away on a mucopolysacchaRIDE
HSM, cloudy cornea, arthritis, gargoyle, CTS, heart valve probs
Hunter dz
Male, x-linked mild compared to hurler
Osteogenesis imperfecta genetic mut?
Type 2:
most severe, pulm hypoplasia, hearing loss, blue sclera
Mut: COL1A1, COL1A2
Marfan syndrome
Defect in fibrillin - glycoprotein that forms sheath around elastin
Subluxation of lenses
Pleiotropy
One gene contributes to multiple phenotypic effects
ex, PKU
Incomplete penetrance
Not all with it, show phenotype
ex, BRCA1 - not always CA
Codominance
Both alleles contribute -
ex, blood groups, a1-antitrypsin
Prader Willi
Chr 15 paternal gene is deleted/mutated
hyperphagia, obesity, MR, hypogonadism
Angelman Syn
Angels miss their moms
Chr 15 maternal gene deleted/mutated
Inappropriate laughter, seizures, ataxia, severe MR
Ex of X-linked dominant
Hypophoshpatemic rickets, Rett syn, fragile X, Alport
Mut in achondroplasia
FGFR3 - inhibits chondrocyte proliferation
Li Fraumeni Syn
abnl in TP53
Malignancies at young age - sarcoma, breast, leukemia, adrenal glands
MEN 2A and 2B gene?
RET
Neurofibromatosis genes?
NF1 - chr 17
NF2 - chr 22
CF deletion?
deletion of Phe508
defect in CFTR gene on chr 7
Infections: Pseudomonas, s. aureus, chronic bronchitis
Meconium ileus in newborns, infertility in males, nasal polyps
X linked recessive D/O
Fabry dz Wiskott-Aldrich Ocular albinism G6PD def Hunter syn Bruton agammaglobinemia Hemo A and B Lesch-Nyhan Duchenne (Beckers)
Duchenne mut?
XL frameshift mutation of dystrophin protein
vs. Beckers is non-frameshift insertion
Fragile X
Big balls, jaws and ears
Trinucleotide of CGG in FMR1 gene
MVP
22q11 deletion syndromes
DiGeorge - thymic, parathyroid, cardiac
Velocardiofacial syn - palate, face, cardiac
3rd and 4th pouches
Vit A
Retinol
bumping into things at noc b/c lights go down and rods come out at night
squamous metaplasia - scaly skin, corneal degeneration, Bitot spots
Tx of AML M3 - all-trans retinoic acid
Vit B1
Thiamine
Important to glucose breakdown
Seen in malnutrition and alcoholism
Wernicke-Korsakoff syn
Dry beriberi
Def of Vit B1 thiamine - nerves, sym m wasting
Wet beriberi
Def of Vit B1 thiamine - high output cardiac failure
Vit B3
Niacin - 3 vowels 4 D's - Pellagra D - dermatitis D - dementia D - diarrhea D - death
Excess Niacin
Facial flushing - prostaglandins
Pretx with ASA
Def of Vit B6
Pyridoxine
convulsions, hyperirritability, peripheral neuro
Isoniazid can lead to?
Dev vit B6 - pyridoxine
Vit B9 aka?
Folate
drugs that can cause folate def?
Phenytoin, sulfonamides, methotrexate
Common causes of Vit B12 def?
Malabsorption - celiac’s, enteritis, diphyllobothrium
Lack of IF - pernicious anemia, gastric bypass
Absence of terminal ileum - crohn
what vit can look like B12 def?
Vit E - is an antioxidant that protects RBC and membranes from ROS
Hemo anemia, neuro
Kwashiorkor
Protein malnutrition
liver fatty change, m wasting, edema
Marasmus
Total calorie malnutrition
emaciation
what drug if taken and then drinking can have disulfram like effects?
Metronidazole
Fomepizole
Inhibits alcohol dehydrogenase
Used for antidote to methanol or ethylene glycol poisoning
Garlic breath?
Arsenic poisoning
G6PD Def
Decreased NADPH -> hemolytic anemia
XLR - inc malarial resistance
Heinz bodies - denatured Hb ppts
Bite cells - Macro bite into the Heinz ketchup bodies
Assoc with G6PD Def?
Sulfonamides Primaquine Nitrofurantoin Isoniazid Fava beans Dapsone Chlorquine
Essential fructosuria
defect in fructokinase, asx, fructose in blood and urine
Fructose intolerance
Def of aldolase B
Fructose-1-phosphate accumulates
Galactokinase def
can get infantile cataracts
Tryptophan derivative
B6 –> niacin –> VAD
Serotonin –> Melationin
Glycine derivative
Porphyrin –> heme
Glutamate derivative
GABA - inhibit
Glutathione - antioxidant
Arginine derivative
Creatine
Urea
NO - vasodilation
PKU def of what 2 things?
MC: phenylalanine hydrolase
tetrahydrobiopterin cofactor
Maple syrup urine dz
Blocked degradation of branched AA - LIV
L - leucine
I - isoleucine
V - baline
Alkaptonuria
Dark like Al Capone
can’t degrade tyrosine
Def of homgentisate oxidase
Urine black - black/blue CT and sclera