USMLE Step 1 - uWorld High Yield Notes Adapted
from Questions with Complete Solutions | Graded A+ |
New Update 2025
What are the two major microtubular motor proteins? Which does anterograde
axonal transport, which does retrograde axonal transport? - ANSWER Kinesin,
Dynein
Kinesin: Anterograde
Dynein: Retrograde`
What do you think, immunologically speaking, when you see someone with
recurrent Neisseria infections? - ANSWER Inability to form the membrane
attack (MAC) complex
this is a common complement deficiency
What is the defect in Chronic Granulomatous disease? What is the
pathophysiology? - ANSWER NADPH Oxidase deficiency leads to the inability
to kill intracellular organisms
Characteristic triad of ataxia telangiectasia? - ANSWER cerebellar ataxia,
telangiectasias, increased risk of sinopulmonary infections
What is the major immune deficiency of ataxia telangiectasia? - ANSWER IgA
deficiency, which predisposes to infections of the upper and lower airways (and
other mucous membranes)
,There's a useful mnemonic for Ataxia Telangiectasia and the gene that's mutated.
What is it? - ANSWER ATM
Ataxia
Telangiectasia
Mutated
ATM gene is responsible for DNA break repair
What is one reason that lead intoxication causes hypochromic anemia? -
ANSWER Mitochondrial iron transport is important for Heme synthesis! It's
inhibited by lead. So you don't make heme in your mitochondria and you get
hypochromic anemia.
What is the biochemical problem in Lesch-Nyhan syndrome? (And, only if you got
that right, what are the really cool symptoms of it?) - ANSWER Defective
purine catabolism, so buildup of purines. It's an X-linked recessive disorder with
mutated HGPRT gene (hypoxanthine-guanine phosphoribosyltransferase, if you
want to impress people).
Now, if you got HGPRT and purine catabolism right, you can say: self-mutilating
behavior on top of mental retardation, choreoathetoid (think Chorea) movements
and spasticity.
What is the defect in Niemann-Pick disease?
What causes that?
,What is the common macular finding? - ANSWER Sphingolipid degradation is
defective
Caused by an autosomal recessive defect in sphingomyelinase
Cherry Spot on the macula? Niemann Pick's or Tay Sach's.
If a baby gets exposed to an unclean knife (...) and subsequently develops rigid
paralysis, what is the diagnosis, where do we think this might happen, and how do
we prevent it? - ANSWER Neonatal Tetanus
Developing Countries
Maternal immunization with tetanus toxoid is the best way to prevent it
an adeuately immunized mom will transfer IgG's across the placenta to the
neonate
Which microtubule associated protein aids in anterograde transport of
intracellular vesicles and organelles? Which end of the microtubule do they go
towards? - ANSWER Kinesin.
Towards the (+) rapidly growing end.
What is an early BRAIN finding of Ataxia-Telangiectasia and how does it manifest
itself? - ANSWER Cerebellar atrophy
manifests as ataxia in the first years of life.
, High yield path association for Alzheimer's disease? - ANSWER Neurofibrillary
tangles in the neocortex
High yield path association for Parkinson's disease? - ANSWER Loss of neurons
in the substantia nigra
High yield path association for Huntington disease? - ANSWER Atrophy of
caudate nucleus
What are the major manifestations of Ataxia-telangiectasia? - ANSWER
cerebellar ataxia, oculocutaneous tenlangiectasias, repeated sinopulmonary
infections, and an increased incidence of malignancy
If you heard: amenorrhea, bitemporal hemianopsia, and enlargement of the
pituitary gland on brain imaging, what would you be thinking? - ANSWER
Prolactinoma, the most common pituitary adenoma.
What embryological layer is the anterior pituitary derived from? - ANSWER
Surface ectoderm
What is the most common congenital abnormality associated with the use of
Sodium Valproate during pregnancy? - ANSWER neural tube defects, e.g.,
meningocele
because valproate inhibits intestinal folic acid absorption resulting in
teratogenicity
from Questions with Complete Solutions | Graded A+ |
New Update 2025
What are the two major microtubular motor proteins? Which does anterograde
axonal transport, which does retrograde axonal transport? - ANSWER Kinesin,
Dynein
Kinesin: Anterograde
Dynein: Retrograde`
What do you think, immunologically speaking, when you see someone with
recurrent Neisseria infections? - ANSWER Inability to form the membrane
attack (MAC) complex
this is a common complement deficiency
What is the defect in Chronic Granulomatous disease? What is the
pathophysiology? - ANSWER NADPH Oxidase deficiency leads to the inability
to kill intracellular organisms
Characteristic triad of ataxia telangiectasia? - ANSWER cerebellar ataxia,
telangiectasias, increased risk of sinopulmonary infections
What is the major immune deficiency of ataxia telangiectasia? - ANSWER IgA
deficiency, which predisposes to infections of the upper and lower airways (and
other mucous membranes)
,There's a useful mnemonic for Ataxia Telangiectasia and the gene that's mutated.
What is it? - ANSWER ATM
Ataxia
Telangiectasia
Mutated
ATM gene is responsible for DNA break repair
What is one reason that lead intoxication causes hypochromic anemia? -
ANSWER Mitochondrial iron transport is important for Heme synthesis! It's
inhibited by lead. So you don't make heme in your mitochondria and you get
hypochromic anemia.
What is the biochemical problem in Lesch-Nyhan syndrome? (And, only if you got
that right, what are the really cool symptoms of it?) - ANSWER Defective
purine catabolism, so buildup of purines. It's an X-linked recessive disorder with
mutated HGPRT gene (hypoxanthine-guanine phosphoribosyltransferase, if you
want to impress people).
Now, if you got HGPRT and purine catabolism right, you can say: self-mutilating
behavior on top of mental retardation, choreoathetoid (think Chorea) movements
and spasticity.
What is the defect in Niemann-Pick disease?
What causes that?
,What is the common macular finding? - ANSWER Sphingolipid degradation is
defective
Caused by an autosomal recessive defect in sphingomyelinase
Cherry Spot on the macula? Niemann Pick's or Tay Sach's.
If a baby gets exposed to an unclean knife (...) and subsequently develops rigid
paralysis, what is the diagnosis, where do we think this might happen, and how do
we prevent it? - ANSWER Neonatal Tetanus
Developing Countries
Maternal immunization with tetanus toxoid is the best way to prevent it
an adeuately immunized mom will transfer IgG's across the placenta to the
neonate
Which microtubule associated protein aids in anterograde transport of
intracellular vesicles and organelles? Which end of the microtubule do they go
towards? - ANSWER Kinesin.
Towards the (+) rapidly growing end.
What is an early BRAIN finding of Ataxia-Telangiectasia and how does it manifest
itself? - ANSWER Cerebellar atrophy
manifests as ataxia in the first years of life.
, High yield path association for Alzheimer's disease? - ANSWER Neurofibrillary
tangles in the neocortex
High yield path association for Parkinson's disease? - ANSWER Loss of neurons
in the substantia nigra
High yield path association for Huntington disease? - ANSWER Atrophy of
caudate nucleus
What are the major manifestations of Ataxia-telangiectasia? - ANSWER
cerebellar ataxia, oculocutaneous tenlangiectasias, repeated sinopulmonary
infections, and an increased incidence of malignancy
If you heard: amenorrhea, bitemporal hemianopsia, and enlargement of the
pituitary gland on brain imaging, what would you be thinking? - ANSWER
Prolactinoma, the most common pituitary adenoma.
What embryological layer is the anterior pituitary derived from? - ANSWER
Surface ectoderm
What is the most common congenital abnormality associated with the use of
Sodium Valproate during pregnancy? - ANSWER neural tube defects, e.g.,
meningocele
because valproate inhibits intestinal folic acid absorption resulting in
teratogenicity
