USMLE First Aid Flashcards
Duchenne disease typically due to
frameshift (deletions, duplications, or nonsense) mutations
which protein is defective in duchenne?
dystrophin
Duchenne=Deleted Dystrophin
Becker disorder typically due to
non-frameshift insertions
which protein is partially defective in Becker’s?
dystrophin
-only partially defective so less severe than Duchenne’s
Down syndrome involves which chromosome?
Chromosome 21 (trisomy 21) -Drinking age (21)
Edwards syndrome involves which chromosome?
Chromosome 18 (trisomy 18) -Election age (18)
Patau syndrome involves which chromosome?
Chromosome 13 (trisomy 13) -Puberty (13)
Cri-du-chat syndrome has what notable sx?
high-pitched crying/mewing
cri du chat= cry of cat
Fat soluble vitamins
A, D, E, K
water soluble vitamins
B1 (thiamine: TTP) B2 (riboflavin: FAD, FMN) B3 (niacin: NAD+) B5 (pantothenic acidS: CoA) B6 (pyridoxine: PLP) B7 (biotin) B9 (folate) B12 (cobalamin) C (ascorbic acid)
Vit A
aka
function
- Retinol
- vision and skin
Vit B1
aka
function
- Thiamin
- in thiamin pyrophospate (TPP), a cofactor for several dehydrogenase enzyme rxns
which two conditions result from thiamin deficiency?
- Wernicke-Korsakoff syndrome
- Beriberi
Vit B2
aka
function
- Riboflavin
- FAD and FMN are derived from riboFlavin, cofactors in redox rxns
Vit B2 deficiency leads to what sx?
Cheilosis
Corneal vascularization
*2Cs of B2
Vit B3
aka
function
- Niacin
- NAD derived from niacin
Vit B3 deficiency leads to what dz? what are the sx of this dz?
- Pellagra
- Diarrhea, Dementia, Dermatitis (3 D’s of B3)
Vit B5
aka
function
- pantothenic acid (B5 is “pento” thenic)
- coenzyme A (CoA) is derived from pantothenic acid
Vit B6
aka
function
- pyridoxine
- pyridoxal phosphate (PLP) is derived from pyridoxine, a cofactor in transamination, decarboxylation, glycogen phosphorylase
Vit B7
aka
function
- biotin
- cofactor for carboxylation enzymes (add a 1-carbon group)
deficiency of biotin is rare, but excessive consumption of what might cause a deficiency?
egg whites or antibiotics
“AVIDin in egg whites AVIDly binds biotion”
Vit B9
aka
function
- folate
- tetrahydrofolic acid (THF) derived from folate, (a coenzyme for 1-carbon transfer/methylation)
folate deficiency leads to what dz?
macrocytic megaloblastic anemia
hypersegmented polymorphonuclear cells (PMNs)
when is folate deficiency seen?
alcoholism
pregnancy
Vit B12
aka
function
storage
- cobalamin
- cofactor for homocystein methyltransferase (transfers CH3 groups) and methylmalonyl-CoA mutase
- liver, large reserve pool (several years)
B12 def leads to what? caused by?
macrocytic megaloblastic anemia
hypersegmented PMNs
insufficient meat intake -> veganism
malabsorption
lack of intrinsic factor -> pernicious anemia
Vit C
aka
function
- ascorbic acid
- antioxidant, facilitates iron absorption by reducing it to Fe2+, collagen synthesis, converting dopamine -> NE
Vit C def leads to what dz?
scurvy (vit C cause sCurvy due to Collagen synthese defect)
Vit D
types
D2- from plants
D3- from milk and exposure to sun
25- OH D3 - storage form
1,25-(OH)2 D3 = calcitriol = active form
Vit D
function
incr intestinal absorption of calcium and phosphate
incr bone mineralization
Vit D deficiency leads to what dz?
Rickets - children
Osteomalacia - adults
Vit K
aka
function
- phytomenadione, phylloquinone, phytoandione
- K is for Klotting, necessary for the maturation of clotting factors II, VII, IX, X and proteins C and S
Vit K is an antagonist to which medication?
Warfarin
Vit K deficiency leads to? when might this occur?
-neonatal hemorrhage with incr PT and aPTT (extrinsic and intrinsic respectively) and normal bleeding time
-neonates have sterile intestines and are therefore unable to synthesize Vit K (therefore Vit K shot is given at birth)
and after prolonged use of broad-spectrum abx (disruption of flora)
Kwashiorkor, a protein malnutrition dz, has what clinical picture?
Kwashiorkor results from a protein def MEAL: Malnutrition Edema Anemia Liver (fatty)
Marasmus, a total calorie malnutrition dz, has what clinical picture?
Marasmus results in Muscle wasting
