USMLE Step 1 Question of the Week #13

A 26-year-old man presents to ophthalmologist for complain of progressive loss of vision in his right eye for last six months. He has visited multiple doctors till date, but there is no improvement. There is no history of pain or redness in eyes. He often experiences fatigue for last one year. His detailed medical history reveals that he has suffered from fractures of different long bones two times; both the fractures were associated with minor injury. His detailed ophthalmologic evaluation suggests diagnosis of optic atrophy on right side. His recent complete blood counts revealed that his blood hemoglobin level was 9.2 g/dL (5.71 mmol/L). Considering a specific condition as a differential diagnosis, the ophthalmologist orders radiogram of his spine, which confirms the diagnosis. The radiogram is shown below:

Which of the following mechanisms best explains pathophysiology of the condition the man is suffering from?

A. Abnormal accumulation of mucopolysaccharides in chondrocytes

B. Decreased synthetic activity of osteoblasts

C. Primary oversecretion of parathyroid hormone

D. Defective acidification of osteoclast resorption pit

E. Defective assembly of collagen polypeptides.


QID #1838

USMLE Step 1 Question of the Week #12

A male newborn, delivered at full term, has abnormal facies and is suspected to have a chromosomal anomaly. Histological examination of his umbilical cord shows following findings:

Which of the following chromosomal anomalies is most commonly associated with above findings in umbilical cord?


A. Down syndrome

B. Edward syndrome

C. Klinefelter syndrome

D. Patau syndrome

E. Turner syndrome

QID #1023

USMLE Step 1 Question of the Week #12

A 60-year-old man presents to ophthalmologist with history of progressive decline in vision in his right eye for last six months. After complete ocular examination, the ophthalmologist confirms diagnosis of cataract in his right eye. Additionally, he also notes a congenital defect in his iris on both sides. Image of the iris defect in his left eye is shown below.

Failure of closure of choroid fissure during which week of gestation results in above defect?

A. Week 6

B. Week 7

C. Week 8

D. Week 10

E. Week 11

QID #1017

USMLE Step 1 Question of the Week #11

A 27-year-old woman comes to the clinic and complains of difficulty with sexual intercourse. History taking proves to be difficult as she is very unwilling to discuss her perceived reasons for the difficulties. She claims that she is in a new relationship and met her current partner two weeks ago. In addition, she reports that she has never had any problem in initiating and maintaining sexual activity in her past relationships and that the lack of desire has also never been a problem. Apart from this, she states that she was sexually abused when she was a child but does not want to talk about it at all. Her chief complaint is that she has pain and stiffness during intercourse and that this has started only with this relationship. On examination, the physiciannotices some resistance during vaginal examination and the patient also complains of pain when he attempts this examination. What is the most likely diagnosis?

A. Dyspareunia

B. Vaginismus

C. Hypoactive sexual disorder

D. Sexual aversion disorder

E. Female sexual arousal disorder

QID #809

USMLE Step 1 Question of the Week #10

A 64-year-old post-menopausal woman has been recently diagnosed with breast cancer stage II. After necessary investigations, surgical excision of the tumor was performed and the excised tissue was sent for histopathological examination, which showed that her tumor cells were positive for estrogen receptors. She was prescribed combination of tamoxifen and cytotoxic chemotherapy. On her follow up after 6 weeks, she complained of hot flashes and vaginal bleeding. The physician explained that the symptoms were due to side effects of tamoxifen. After complete physical examination, her blood sample was sent for follow up laboratory examination, which showed an electrolyte imbalance.

Provided that her other medications are not interfering with electrolyte balance, which of the following electrolyte defects is most likely caused by tamoxifen?

A. Hypercalcemia
B. Hypernatremia
C. Hyperkalemia
E. Hypermagnesemia

QID #895

USMLE Step 1 Question of the Week #9

A 55-year-old man presents to physician with complain of difficulty in breathing for last two weeks. He mentions that he coughs frequently over last five years, but he has ignored the symptom because he thought it was due to smoking. He is a chronic smoker for last fifteen years. There is no history of fever or chest pain. On physical examination, his temperature is 98.8ºF (37.1ºC), respirations are 28/minute, pulse rate is 88/minute, and blood pressure is 124/84 mm Hg. Auscultation of chest reveals wheezing and decreased intensity of breath sounds over suprascapular and supramammary regions bilaterally. Hyperresonance is present over the same areas on percussion. Chest radiogram of the man shows hyperinflation of upper lobes of both the lungs. His pulmonary function testing shows FEV1 82% of predicted and FEV1/FVC 0.65. His total lung capacity is increased and diffusing capacity is reduced. His serum α1-antitrypsin level is normal. Which of the following parts of lower respiratory tract is most likely to be affected maximally in the patient?

A. Bronchioles

B. Terminal bronchioles

C. Respiratory bronchioles

D. Alveolar ducts

E. Alveolar sacs

QID #2311

USMLE Step 1 Question of the Week #8

A 68-year-old man presents to physician with complain of fever, cough, and difficulty in breathing for last three days. He mentions that his expectorations are rust-colored. He has no known medical disorder and is otherwise a healthy man. On physical examination, his temperature is 103.7ºF (39.8ºC), pulse rate is 92/minute, blood pressure is 128/82 mm Hg, and respirations are 24/minute. Auscultation of his chest reveals decreased intensity of breath sounds and presence of crepitations over right infrascapular region. The physician orders his sputum examination, which shows predominant polymorphonuclear neutrophils and a few epithelial cells. Gram staining of sputum confirms presence of Gram-positive cocci in pairs. Chest radiogram of the man shows lobar consolidation in lower zone of the right lung. Which of the following best describes pathological changes in the affected area of the lung?

A. Neutrophil-rich exudate filling bronchi, bronchioles, and adjacent alveoli

B. Widening of alveolar septa and mononuclear inflammatory infiltrate

C. Fibrin strands in alveolar spaces and extravasation of red blood cells

D. Intra-alveolar fluid and vascular engorgement

E. Fibromyxoid masses rich in fibroblasts and macrophages

QID #2309

USMLE Step 1 Question of the Week #7

A 24-year-old woman presents to physician with complain of cough and wheezing for three days. She mentions that she has been experiencing similar episodes for last two years and the episodes are more frequent in winter months as compared to other seasons. Cough is usually non-productive or with scanty expectoration. Use of inhaled salbutamol, as prescribed by his physician one year back, quickly relieves her symptoms. Her mother is a known case of allergic rhinitis. On physical examination, her temperature is 98.4ºF (36.9ºC), pulse rate is 84/minute, blood pressure is 128/80 mm Hg, and respirations are 22/minute. Auscultation of her lungs shows presence of end-expiratory wheezing bilaterally. Her peak expiratory flow rate is 70% of expected for her age, which improves to 90% of expected for her age after use of inhaled salbutamol. The physician suggests her a few laboratory investigations for diagnostic evaluation. Her differential white blood cell count show 9% of eosinophils and microscopic examination of her sputum shows numerous eosinophils and crystals.

Which of the following proteins is most likely to be present in the crystals?

A. Spondin-1

B. Protein

C. E-selectin

D. Galectin-10

E. Laminin

QID # 2311

USMLE Step 1 Question of the Week #6

6. A 48-year-old Japanese man presents to the clinic with multiple skin lesions as seen in the image:


He also complains of unintentional loss of weight even on a good diet and a healthy appetite. He denies smoking or alcohol abuse. On examination, the lesions are flat, velvety, hyperpigmented well defined lesions with a stuck-on appearance. The rest of the physical examination is unremarkable. Which of the following is the best investigation to be considered next in this patient?

A. Biopsy of lesion

B. Chest x-ray

C. Chest CT

D. Abdominal CT

E. Electrolytes


USMLE Step 1 Question of the Week #5

A 68-year-old male, a recent immigrant from Africa, and a known case of hypertension for the last five years, presents in emergency with a complaint of difficulty in vision for last one day. The patient had similar episodes in the past, but they resolved by themselves. He was taking antihypertensive medications for last three years, and his blood pressure has been under control. His father died due to road accident when he was only seven years old. All other family members are healthy. On examination, his pulse is 104 beats/mins, BP 140/80 mmHg, respiratory rate is 17 breath/min. Chest and cardiovascular examinations are normal. Abdominal examination reveals a mass in left lumbar region. Laboratory studies show:

Hemoglobin:                18.8 g/dL

Leukocytes:                 9200/mm3

Platelet count:              259000 /mm3

Random Blood Sugar: 107 mg//dL

Blood Urea Nitrogen:   19 mg/dL

Serum Creatinine:        1.4 mg/dL

Serum Sodium:                        140 mEq/L

Serum Potassium:        4.0 mEq/L

Serum Calcium:           8.9 mg/dL

Serum Magnesium:      1.6 mEq/L

Serum Bicarbonate:     24 mEq/L

Serum Cholesterol:      210 mg/dL

HbA1c:                        6.3

After CT scan brain, the patient underwent a whole body imaging. Images are shown below:


Which of the following genes are responsible for this disease from which patient is suffering?

A. VHL suppressor gene

B. FGFR3 gene

C. CFTR gene

D. CNBP and DMPK genes


Ref: Q.ID #953