COMSAE PHASE 1 FORM 115 STYLE EXAM
2026–2027 | COMLEX LEVEL 1 PREP |
VERIFIED QUESTIONS & ANSWERS |
COMPREHENSIVE STUDY GUIDE PDF
COMLEX LEVEL 1 PREP EXAM 2026–2027 | FORM 115 STYLE COMPREHENSIVE
STUDY GUIDE
• Features: Verified high-yield multiple-choice questions organized across all
COMLEX Level 1 domains including osteopathic principles, clinical medicine,
pharmacology, pathology, and OMM; designed to mirror actual exam difficulty and
question distribution for optimal preparation.
• How to Study: Complete this exam under timed conditions (approximately 4
hours for questions), review all EXPERT RATIONALE regardless of performance,
focus on weak content areas, and repeat sections to reinforce osteopathic concepts
and clinical decision-making skills.
QUESTIONS
Question 1. A 45-year-old male presents with low back pain radiating into his
left leg. On physical examination, he has a positive straight leg raise test and
diminished left ankle reflex. Which nerve root is most likely compressed?
A) L2
B) L3
C) L4
D) L5
E) S1
CORRECT ANSWER: E) S1
EXPERT RATIONALE: The combination of low back pain radiating into the leg,
positive straight leg raise test, and diminished ankle reflex indicates S1 nerve root
compression. The ankle reflex (Achilles) is mediated by the S1 nerve root. L5
radiculopathy would typically present with foot drop and weakness of foot
,dorsiflexion, while L4 presents with knee reflex changes. The clinical triad described
is classic for S1 involvement.
Question 2. A 32-year-old woman presents with acute onset of visual loss,
weakness in her right arm, and numbness in her left leg. Where is the most
likely location of the lesion?
A) Right cerebral hemisphere
B) Left brainstem
C) Right midbrain
D) Corpus callosum
E) Right pons
CORRECT ANSWER: B) Left brainstem
EXPERT RATIONALE: This presentation describes Weber syndrome with crossed
syndrome characteristics. Ipsilateral cranial nerve findings (oculomotor nerve
affecting the right eye/vision) combined with contralateral motor and sensory
deficits (right arm weakness, left leg numbness) indicate a brainstem lesion. The left
brainstem would affect the left oculomotor nerve and crossed motor/sensory
pathways, producing right-sided weakness and left-sided sensory loss, consistent
with the classic crossed syndrome pattern.
Question 3. A 28-year-old male with a history of seasonal allergies now
presents with acute dyspnea, wheezing, and urticaria 15 minutes after eating
shellfish at a restaurant. His blood pressure is 88/52 mmHg. Which mediator is
primarily responsible for the cardiovascular collapse in this patient?
A) Histamine
B) Tryptase
C) Leukotrienes
D) Prostaglandins
,E) Bradykinin
CORRECT ANSWER: A) Histamine
EXPERT RATIONALE: This patient is experiencing acute anaphylaxis triggered by
shellfish. Histamine, released by mast cell and basophil degranulation, is the
primary mediator responsible for the immediate cardiovascular manifestations
including hypotension and shock. While other mediators contribute to the
anaphylactic response (leukotrienes cause bronchoconstriction, tryptase is a
marker), histamine's rapid vasodilatory effects on vascular smooth muscle make it
the major contributor to immediate cardiovascular collapse and shock.
Question 4. A 55-year-old male smoker presents with hemoptysis and a
cavitary lesion in the right upper lobe seen on chest X-ray. Acid-fast bacilli are
identified on sputum smear. Which genetic factor most significantly increases
tuberculosis susceptibility?
A) HLA-B27 polymorphism
B) NRAMP1 (Natural Resistance-Associated Macrophage Protein 1) polymorphism
C) IL-10 receptor deficiency
D) TNF-alpha gene polymorphism
E) MHC Class II mutations
CORRECT ANSWER: B) NRAMP1 (Natural Resistance-Associated Macrophage
Protein 1) polymorphism
EXPERT RATIONALE: NRAMP1 is a metal ion transporter essential for intracellular
immunity against mycobacteria. Polymorphisms in the NRAMP1 gene are strongly
associated with tuberculosis susceptibility and progression, particularly in African
and Asian populations. This protein facilitates phagosomal acidification and
antimicrobial activity of macrophages. While TNF-alpha and IL-10 are important in
TB immunity, NRAMP1 polymorphisms show the strongest genetic association with
TB susceptibility globally.
, Question 5. A 42-year-old female presents with progressive fatigue, dyspnea
on exertion, and palpitations. Laboratory studies reveal Hgb 8.2 g/dL with
hypochromic, microcytic indices. Serum iron is elevated at 250 mcg/dL, and
transferrin saturation is 88%. Which genetic mutation is most likely
responsible for this presentation?
A) Beta-globin gene mutation
B) HFE gene mutation (C282Y)
C) Alpha-thalassemia deletion
D) PKLR gene mutation
E) SLC11A2 gene mutation
CORRECT ANSWER: B) HFE gene mutation (C282Y)
EXPERT RATIONALE: The clinical and laboratory presentation is consistent with
hemochromatosis. The HFE gene mutation (most commonly C282Y homozygosity)
is responsible for approximately 85-90% of hereditary hemochromatosis cases. The
elevated serum iron, high transferrin saturation, and microcytic anemia secondary
to iron accumulation are hallmark findings. The C282Y mutation impairs hepcidin
regulation, leading to excessive intestinal iron absorption. Early diagnosis and
treatment with phlebotomy can prevent organ damage.
Question 6. A 7-year-old boy with chronic otitis media is brought to clinic by
his mother. On examination, you note OME (otitis media with effusion). Which
structure in the middle ear is responsible for drainage of middle ear fluid?
A) Stapes
B) Incus
C) Eustachian tube
D) Tympanic membrane
E) Malleus
CORRECT ANSWER: C) Eustachian tube
2026–2027 | COMLEX LEVEL 1 PREP |
VERIFIED QUESTIONS & ANSWERS |
COMPREHENSIVE STUDY GUIDE PDF
COMLEX LEVEL 1 PREP EXAM 2026–2027 | FORM 115 STYLE COMPREHENSIVE
STUDY GUIDE
• Features: Verified high-yield multiple-choice questions organized across all
COMLEX Level 1 domains including osteopathic principles, clinical medicine,
pharmacology, pathology, and OMM; designed to mirror actual exam difficulty and
question distribution for optimal preparation.
• How to Study: Complete this exam under timed conditions (approximately 4
hours for questions), review all EXPERT RATIONALE regardless of performance,
focus on weak content areas, and repeat sections to reinforce osteopathic concepts
and clinical decision-making skills.
QUESTIONS
Question 1. A 45-year-old male presents with low back pain radiating into his
left leg. On physical examination, he has a positive straight leg raise test and
diminished left ankle reflex. Which nerve root is most likely compressed?
A) L2
B) L3
C) L4
D) L5
E) S1
CORRECT ANSWER: E) S1
EXPERT RATIONALE: The combination of low back pain radiating into the leg,
positive straight leg raise test, and diminished ankle reflex indicates S1 nerve root
compression. The ankle reflex (Achilles) is mediated by the S1 nerve root. L5
radiculopathy would typically present with foot drop and weakness of foot
,dorsiflexion, while L4 presents with knee reflex changes. The clinical triad described
is classic for S1 involvement.
Question 2. A 32-year-old woman presents with acute onset of visual loss,
weakness in her right arm, and numbness in her left leg. Where is the most
likely location of the lesion?
A) Right cerebral hemisphere
B) Left brainstem
C) Right midbrain
D) Corpus callosum
E) Right pons
CORRECT ANSWER: B) Left brainstem
EXPERT RATIONALE: This presentation describes Weber syndrome with crossed
syndrome characteristics. Ipsilateral cranial nerve findings (oculomotor nerve
affecting the right eye/vision) combined with contralateral motor and sensory
deficits (right arm weakness, left leg numbness) indicate a brainstem lesion. The left
brainstem would affect the left oculomotor nerve and crossed motor/sensory
pathways, producing right-sided weakness and left-sided sensory loss, consistent
with the classic crossed syndrome pattern.
Question 3. A 28-year-old male with a history of seasonal allergies now
presents with acute dyspnea, wheezing, and urticaria 15 minutes after eating
shellfish at a restaurant. His blood pressure is 88/52 mmHg. Which mediator is
primarily responsible for the cardiovascular collapse in this patient?
A) Histamine
B) Tryptase
C) Leukotrienes
D) Prostaglandins
,E) Bradykinin
CORRECT ANSWER: A) Histamine
EXPERT RATIONALE: This patient is experiencing acute anaphylaxis triggered by
shellfish. Histamine, released by mast cell and basophil degranulation, is the
primary mediator responsible for the immediate cardiovascular manifestations
including hypotension and shock. While other mediators contribute to the
anaphylactic response (leukotrienes cause bronchoconstriction, tryptase is a
marker), histamine's rapid vasodilatory effects on vascular smooth muscle make it
the major contributor to immediate cardiovascular collapse and shock.
Question 4. A 55-year-old male smoker presents with hemoptysis and a
cavitary lesion in the right upper lobe seen on chest X-ray. Acid-fast bacilli are
identified on sputum smear. Which genetic factor most significantly increases
tuberculosis susceptibility?
A) HLA-B27 polymorphism
B) NRAMP1 (Natural Resistance-Associated Macrophage Protein 1) polymorphism
C) IL-10 receptor deficiency
D) TNF-alpha gene polymorphism
E) MHC Class II mutations
CORRECT ANSWER: B) NRAMP1 (Natural Resistance-Associated Macrophage
Protein 1) polymorphism
EXPERT RATIONALE: NRAMP1 is a metal ion transporter essential for intracellular
immunity against mycobacteria. Polymorphisms in the NRAMP1 gene are strongly
associated with tuberculosis susceptibility and progression, particularly in African
and Asian populations. This protein facilitates phagosomal acidification and
antimicrobial activity of macrophages. While TNF-alpha and IL-10 are important in
TB immunity, NRAMP1 polymorphisms show the strongest genetic association with
TB susceptibility globally.
, Question 5. A 42-year-old female presents with progressive fatigue, dyspnea
on exertion, and palpitations. Laboratory studies reveal Hgb 8.2 g/dL with
hypochromic, microcytic indices. Serum iron is elevated at 250 mcg/dL, and
transferrin saturation is 88%. Which genetic mutation is most likely
responsible for this presentation?
A) Beta-globin gene mutation
B) HFE gene mutation (C282Y)
C) Alpha-thalassemia deletion
D) PKLR gene mutation
E) SLC11A2 gene mutation
CORRECT ANSWER: B) HFE gene mutation (C282Y)
EXPERT RATIONALE: The clinical and laboratory presentation is consistent with
hemochromatosis. The HFE gene mutation (most commonly C282Y homozygosity)
is responsible for approximately 85-90% of hereditary hemochromatosis cases. The
elevated serum iron, high transferrin saturation, and microcytic anemia secondary
to iron accumulation are hallmark findings. The C282Y mutation impairs hepcidin
regulation, leading to excessive intestinal iron absorption. Early diagnosis and
treatment with phlebotomy can prevent organ damage.
Question 6. A 7-year-old boy with chronic otitis media is brought to clinic by
his mother. On examination, you note OME (otitis media with effusion). Which
structure in the middle ear is responsible for drainage of middle ear fluid?
A) Stapes
B) Incus
C) Eustachian tube
D) Tympanic membrane
E) Malleus
CORRECT ANSWER: C) Eustachian tube
