Genetic and environmental risk factors — MCQs

A researcher is investigating whether there is an association between the use of social media in teenagers and bipolar disorder. In order to study this potential relationship, she collects data from people who have bipolar disorder and matched controls without the disorder. She then asks how much on average these individuals used social media in the 3 years prior to their diagnosis. This continuous data is divided into 2 groups: those who used more than 2 hours per day and those who used less than 2 hours per day. She finds that out of 1000 subjects, 500 had bipolar disorder of which 300 used social media more than 2 hours per day. She also finds that 400 subjects who did not have the disorder also did not use social media more than 2 hours per day. Which of the following is the odds ratio for development of bipolar disorder after being exposed to more social media?

A 52-year-old woman presents to her primary care physician for her annual checkup. She lost her job 6 months ago and since then she has been feeling worthless because nobody wants to hire her. She also says that she is finding it difficult to concentrate, which is exacerbated by the fact that she has lost interest in activities that she used to love such as doing puzzles and working in the garden. She says that she is sleeping over 10 hours every day because she says it is difficult to find the energy to get up in the morning. She denies having any thoughts about suicide. Which of the following neurotransmitter profiles would most likely be seen in this patient?

A 45-year-old man presents with a hereditary condition affecting iron metabolism. The condition is caused by mutations in a gene that normally stimulates hepatic production of hepcidin, a hormone that downregulates iron absorption by inhibiting ferroportin (an iron transporter) on enterocytes. Due to this genetic defect, the patient has developed iron overload. He presents with skin hyperpigmentation, fatigue, joint pain, and diabetes mellitus. Laboratory studies show elevated serum ferritin and transferrin saturation. The patient is also developing early signs of cardiovascular complications from iron deposition. What would be the first cardiac manifestation in this patient?

A 36-year-old woman is brought to the emergency room by her husband for “weird behavior" for the past several weeks. He reports that her right arm has been moving uncontrollably in a writhing movement and that she has been especially irritable. She has a history of depression, which was diagnosed 4 years ago and is currently being treated with sertraline. She denies any recent fever, trauma, infections, travel, weakness, or sensory changes. She was adopted so is unsure of her family history. Which of the following is the most likely explanation for her symptoms?

A 20-year-old college student comes to the physician because she has been extremely sad for the past 3 weeks and has to cry constantly. Three weeks ago, her boyfriend left her after they were together for 4 years. She has no appetite and has had a 2.3-kg (5.1-lb) weight loss. She has missed several classes because she could not stop crying or get out of bed. She thinks about her ex-boyfriend all the time. She says that she experienced similar symptoms for about 2 months after previous relationships ended. The patient is 158 cm (5 ft 2 in) tall and weighs 45 kg (100 lb); BMI is 18 kg/m2. Her temperature is 36.1°C (97°F), pulse is 65/min, and blood pressure is 110/60 mm Hg. Physical examination shows no abnormalities. On mental status examination she appears sad and cries easily. Which of the following is the most likely diagnosis?

A 42-year-old female presents to her primary care provider for an annual checkup. She reports feeling sad over the past few months for no apparent reason. She has lost interest in swimming, which she previously found enjoyable. Additionally, she has had trouble getting a full night’s sleep and has had trouble concentrating during the day. She has lost 15 pounds since her last visit one year prior. Which of the following sets of neurotransmitter levels is associated with this patient’s condition?

A group of researchers studying the relationship between major depressive disorder and unprovoked seizures identified 36 patients via chart review who had been rehospitalized for unprovoked seizures following discharge from an inpatient psychiatric unit and 105 patients recently discharged from the same unit who did not experience unprovoked seizures. The results of the study show: Unprovoked seizure No seizure Major depressive disorder 20 35 No major depressive disorder 16 70 Based on this information, which of the following is the most appropriate measure of association between history of major depressive disorder (MDD) and unprovoked seizures?

A 75-year-old Caucasian man presents to the emergency department with abdominal pain. The patient states he was at home eating dinner when he began to experience severe abdominal pain. The patient has a past medical history of diabetes, hypertension, and atherosclerosis. He lives at home alone, smokes cigarettes, and drinks 1 to 2 alcoholic drinks per day. The patient is given IV morphine and an ultrasound is obtained demonstrating a dilated abdominal aorta. The patient states that his father died of a similar finding and is concerned about his prognosis. Which of the following is the greatest risk factor for this patient's presentation?

A 55-year-old woman presents to a primary care clinic for a physical evaluation. She works as a software engineer, travels frequently, is married with 2 kids, and drinks alcohol occasionally. She does not exercise regularly. She currently does not take any medications except for occasional ibuprofen or acetaminophen. She is currently undergoing menopause. Her initial vital signs reveal that her blood pressure is 140/95 mmHg and heart rate is 75/min. She weighs 65 kg (143 lb) and is 160 cm (63 in) tall. Her physical exam is unremarkable. A repeat measurement of her blood pressure is the same as before. Among various laboratory tests for hypertension evaluation, the physician requests fasting glucose and hemoglobin A1c levels. Which of the following is the greatest risk factor for type 2 diabetes mellitus?

A 68-year-old man with type 2 diabetes mellitus comes to the physician because of a 5-month history of episodic palpitations, dizziness, and fatigue. His pulse is 134/min and irregularly irregular, and his blood pressure is 165/92 mm Hg. An ECG shows a narrow complex tachycardia with absent P waves. He is prescribed a drug that decreases the long-term risk of thromboembolic complications by inhibiting the extrinsic pathway of the coagulation cascade. The expected beneficial effect of this drug is most likely due to which of the following actions?