Questões de USMLE

A 17-year-old high-school student comes to the school health clinic. She has missed her last menstrual period and is worried about being pregnant. In the past history, it is noted …

A family is afflicted with a form of degenerative muscle disease. All members of the family represented by the pedigree have undergone PCR-based DNA testing, as shown. Based upon t…

A woman whose brother has cystic fibrosis seeks genetic counseling. She is told that she, her brother, and other family members can be tested for the common mutations known to caus…

Pseudogenes are homologues of functional genes that lack promoters and are therefore part of the unexpressed DNA. It is thought that at least some of these pseudogenes were produce…

A newborn presents with severe lymphopenia (WBC 2,800/μL, lymphocytes 8%) discovered on routine screening after an older sibling died from Pneumocystis jirovecii pneumonia at 6 mon…

A 31-year-old woman presents with abnormal cervical cytology. Vital signs are normal (BP 118/76, HR 82, RR 16, Temp 37°C, SpO2 98%). Cervical biopsy demonstrates high-grade squamou…

A 26-year-old woman presents with fever (38.9°C), myalgias, and nonproductive cough during a novel RNA respiratory virus outbreak. Vital signs show HR 102 bpm, RR 20/min, BP 118/76…

A researcher studying metastatic breast cancer cells measures gene expression at multiple levels. She obtains tumor tissue samples and determines messenger RNA levels of HER2 recep…

A 17-year-old girl presents to the emergency department with fever (39.2°C), tachypnea (RR 28), and tachycardia (HR 112). She reports ingesting a large quantity of aspirin 2 hours …

A 2-week-old boy presents with poor feeding and lethargy. Vital signs show HR 145 bpm, RR 32/min, BP 68/42 mmHg, temperature 37.2°C. Laboratory studies reveal high anion gap metabo…

A 7-year-old boy presents with progressive developmental delay, aggressive behavior, and coarse facial features. Vital signs show BP 95/60, HR 102, RR 22, Temp 37.2°C, SpO2 98% on …

A 2-week-old male presents with poor feeding and hypotonia. Newborn screening revealed markedly elevated serum phenylalanine (28 mg/dL; normal <2). Despite strict low-phenylalanine…

A 14-year-old boy presents with recurrent acute pancreatitis. Vital signs show BP 118/76 mmHg, HR 92 bpm, RR 18, temperature 37.2°C, SpO2 98% on room air. Fasting serum appears mil…

A 2-year-old male presents with progressive neurological deterioration, developmental regression, and cherry-red macular spots on ophthalmologic examination. Vital signs show HR 98…

A 32-year-old man with autosomal recessive inheritance disorder (prevalence 1/40,000) presents with progressive neurologic decline. Physical examination reveals BP 118/76, HR 88, R…

A 34-year-old man with type 2 diabetes presents with fatigue and dyspnea on exertion. Vital signs show BP 142/88 mmHg, HR 98 bpm, RR 20/min, temp 37.2°C, SpO2 98% on room air. Seru…

An Olympic runner participates in a 100-meter race. During this race, it is estimated that only ½ L oxygen will be consumed by the runner. However, more than 10 L oxygen would be c…

A 12-year-old male has a particular genetic disease. His mother is a carrier of the mutated gene, but his father is not clinically affected and is not a carrier. The patient has 4 …

A gene product thought to be involved in the down-regulation of fetal hemoglobin expression is being investigated. Samples of primary tissue cultures of fetal, neonatal, and adult …

A 28-year-old woman with known pyruvate kinase deficiency presents with fatigue and jaundice. Vital signs show BP 118/76, HR 102, RR 18, Temp 37.2°C, SpO2 98%. Laboratory studies r…

A 4-year-old male is brought to the pediatrician because of gastroenteritis for 3 days, followed by a brief generalized seizure that left him semicomatose. The blood glucose level …

A 28-year-old woman with type 1 diabetes presents with fatigue and polyuria. Vital signs: BP 118/76, HR 92, RR 18, Temp 37°C, SpO2 98%. She requires 0.8 units/kg/day insulin. A 52-…

An infant receives an exchange blood transfusion due to severe neonatal jaundice. Red blood cell transfusion is required monthly, and at 6 months of age, a splenectomy is performed…

A 2-week-old male presents with projectile vomiting after each milk-based formula feeding and failure to gain weight. Vital signs show HR 128/min, RR 32/min, temperature 37.2°C. Se…