USMLE Step 1 - uWorld High Yield Notes
with Already Verified Answers
What are the two major microtubular motor proteins? Which does
anterograde axonal transport, which does retrograde axonal transport? -
✔✔Kinesin, Dynein
Kinesin: Anterograde
Dynein: Retrograde`
What do you think, immunologically speaking, when you see someone with
recurrent Neisseria infections? - ✔✔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? - ✔✔NADPH Oxidase deficiency leads to the inability to
kill intracellular organisms
Characteristic triad of ataxia telangiectasia? - ✔✔cerebellar ataxia,
telangiectasias, increased risk of sinopulmonary infections
1
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
,What is the major immune deficiency of ataxia telangiectasia? - ✔✔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? - ✔✔ATM
Ataxia
Telangiectasia
Mutated
ATM gene is responsible for DNA break repair
What is one reason that lead intoxication causes hypochromic anemia? -
✔✔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?) - ✔✔Defective
purine catabolism, so buildup of purines. It's an X-linked recessive disorder
2
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
,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? - ✔✔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? - ✔✔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
3
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
, Which microtubule associated protein aids in anterograde transport of
intracellular vesicles and organelles? Which end of the microtubule do they
go towards? - ✔✔Kinesin.
Towards the (+) rapidly growing end.
What is an early BRAIN finding of Ataxia-Telangiectasia and how does it
manifest itself? - ✔✔Cerebellar atrophy
manifests as ataxia in the first years of life.
High yield path association for Alzheimer's disease? - ✔✔Neurofibrillary
tangles in the neocortex
High yield path association for Parkinson's disease? - ✔✔Loss of neurons
in the substantia nigra
High yield path association for Huntington disease? - ✔✔Atrophy of
caudate nucleus
What are the major manifestations of Ataxia-telangiectasia? - ✔✔cerebellar
ataxia, oculocutaneous tenlangiectasias, repeated sinopulmonary
infections, and an increased incidence of malignancy
4
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
with Already Verified Answers
What are the two major microtubular motor proteins? Which does
anterograde axonal transport, which does retrograde axonal transport? -
✔✔Kinesin, Dynein
Kinesin: Anterograde
Dynein: Retrograde`
What do you think, immunologically speaking, when you see someone with
recurrent Neisseria infections? - ✔✔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? - ✔✔NADPH Oxidase deficiency leads to the inability to
kill intracellular organisms
Characteristic triad of ataxia telangiectasia? - ✔✔cerebellar ataxia,
telangiectasias, increased risk of sinopulmonary infections
1
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
,What is the major immune deficiency of ataxia telangiectasia? - ✔✔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? - ✔✔ATM
Ataxia
Telangiectasia
Mutated
ATM gene is responsible for DNA break repair
What is one reason that lead intoxication causes hypochromic anemia? -
✔✔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?) - ✔✔Defective
purine catabolism, so buildup of purines. It's an X-linked recessive disorder
2
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
,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? - ✔✔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? - ✔✔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
3
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
, Which microtubule associated protein aids in anterograde transport of
intracellular vesicles and organelles? Which end of the microtubule do they
go towards? - ✔✔Kinesin.
Towards the (+) rapidly growing end.
What is an early BRAIN finding of Ataxia-Telangiectasia and how does it
manifest itself? - ✔✔Cerebellar atrophy
manifests as ataxia in the first years of life.
High yield path association for Alzheimer's disease? - ✔✔Neurofibrillary
tangles in the neocortex
High yield path association for Parkinson's disease? - ✔✔Loss of neurons
in the substantia nigra
High yield path association for Huntington disease? - ✔✔Atrophy of
caudate nucleus
What are the major manifestations of Ataxia-telangiectasia? - ✔✔cerebellar
ataxia, oculocutaneous tenlangiectasias, repeated sinopulmonary
infections, and an increased incidence of malignancy
4
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
