A 35-year-old male presents to the emergency department with sudden onset of severe abdominal pain. His medical history includes multiple episodes of spontaneous arterial ruptures and a family history of early-onset vascular complications. Physical examination reveals thin, translucent skin with visible veins and hypermobility of the small joints. Genetic testing confirms a mutation in the COL3A1 gene. Which of the following best explains the underlying pathophysiology of this patient’s condition?
A 22-year-old woman presents to the clinic for evaluation of chronic joint pain. She reports frequent joint dislocations with minimal trauma, delayed wound healing, and easy bruising. On examination, she has hyperextensible skin, atrophic scars on her knees and elbows, and generalized joint hypermobility. Cardiac auscultation reveals a mid-systolic click. Which of the following best explains the pathogenesis of this patient’s condition?
A 7-year-old girl with Williams syndrome is seen in clinic for a routine follow-up. She has a history of developmental delay, a characteristic “elfin” facial appearance, and a friendly demeanor. Her parents are concerned about her heart condition, which was noted at birth. The physician reviews her chart and discusses her prognosis. Question: What is the primary cause of mortality in individuals with Williams syndrome, such as this patient?
A 3-year-old boy is brought to the pediatrician for evaluation of developmental delay and frequent irritability. On examination, the child has a broad forehead, elfin-like facies, periorbital fullness, and an overly friendly personality. A harsh systolic ejection murmur is heard at the upper right sternal border. Blood pressure is notably higher in the upper extremities compared to the lower extremities. The physician suspects a genetic disorder. Which of the following is the most likely cause of cardiovascular complications in this patient?
A newborn is delivered at 37 weeks gestation after an uncomplicated pregnancy. Immediately after birth, the infant is noted to have severe midline facial abnormalities, including a single central eye (cyclopia) and a proboscis (a tubular, nose-like structure) above the eye. The infant also exhibits microcephaly (small head size) and hypotonia (low muscle tone). Apgar scores are low, and the baby requires respiratory support shortly after delivery. Imaging studies, including cranial ultrasound and MRI, reveal alobar holoprosencephaly, a severe brain malformation where the forebrain fails to divide into two hemispheres, resulting in a single-lobed brain structure. The infant also has other congenital anomalies, such as cleft lip and palate, polydactyly (extra fingers or toes), and congenital heart defects (e.g., ventricular septal defect). Which chromosomal abnormality is most commonly associated with this condition?
An 82 year-old male with multiple myeloma comes to the emergency room with fatigue and weakness. His hemoglobin is 6.5 g/dL. He receives a blood transfusion and within 30 minutes after the transfusion is started, he develops burning at the infusion site, fever,chills, chest tightness, backache, headache, flank pain and reddish-colored urine. His temperature is 101 ⁰ F, heart rate is 94 beats per minute, respiratory rate is 26 breaths per minute, and blood pressure is 80/55 mm Hg. On physical examination, you see flushing on his face and hear wheezing in the lungs. Laboratory tests reveal hemoglobin 5.9 g/dL, free hemoglobin in urine, decreased serum haptoglobin, increased lactate dehydrogenase, increased indirect bilirubin level and positive direct antigen (Coombs) test. What is the underlying mechanism of this disorder?
A 5-year-old girl with sickle cell disease is brought to the clinic with a 3-day history of fatigue, pallor, and decreased activity. Her mother reports that the child had a mild fever and a “slapped cheek” rash about two weeks ago. Laboratory evaluation shows a significant drop in hemoglobin and a reticulocyte count of 0.2%. Question: What is the most likely diagnosis?
A 32-year-old woman with a history of systemic lupus erythematosus presents with fatigue, pallor, and shortness of breath on exertion. Laboratory tests reveal pancytopenia with a markedly low reticulocyte count. She reports a recent episode of a facial rash and joint pain. Which of the following is the most appropriate next step to determine if parvovirus B19 is the cause of her current condition?
A 7-year-old boy with a history of hereditary spherocytosis presents to the emergency department with sudden onset of pallor, fatigue, and lethargy. His parents report that he had a mild fever and runny nose a week ago, which resolved without treatment. On examination, he appears pale, and laboratory tests reveal a significant drop in hemoglobin levels with a markedly low reticulocyte count. Which of the following is the most likely cause of this patient’s current hematologic findings?
