ATI RN
Hematological System Questions
Question 1 of 5
You are asked to evaluate a 2-day-old boy in the newborn nursery with petechiae who has a platelet count of 8,000/mcL. On further questioning, you learn that he had a maternal uncle who died of intracerebral hemorrhage as a toddler. There is no eczema on physical examination. Review of the smear shows anisocytosis; poikilocytosis; normal white blood cell morphology; and small, infrequent platelets. The neonatologists have sent human platelet antigen (HPA)-1a testing from both parents, which is pending. Which of the following is the most likely diagnosis?
Correct Answer: C
Rationale: The most likely diagnosis in this case is Wiskott-Aldrich syndrome (C). This is because the patient presents with petechiae, low platelet count, anisocytosis, poikilocytosis, and small, infrequent platelets, which are all characteristic of this X-linked recessive disorder. Additionally, the family history of intracerebral hemorrhage in a young child is suggestive of a bleeding disorder. The absence of eczema helps differentiate Wiskott-Aldrich syndrome from other conditions like thrombocytopenia-absent radius syndrome. The pending HPA-1a testing is likely to confirm the diagnosis by ruling out neonatal alloimmune thrombocytopenia (B). Congenital infection (A) would typically present with other symptoms, and May-Hegglin anomaly (D) is characterized by Döhle-like basophilic cytoplasmic inclusions in neutrophils, which are not described in this case
Question 2 of 5
A 7-year-old Hispanic male is referred to the hematology consult service by his pediatrician because of concern for hemoglobinopathy. In his records, you find a hemoglobin electrophoresis performed last year which shows hemoglobin A 78% and hemoglobin F 22%. His complete blood count is normal, and he has normal growth and development. Which of the following is true for this patient?
Correct Answer: D
Rationale: The correct answer is D: Hereditary persistence of fetal hemoglobin results in pancellular hemoglobin F distribution. In this case, the patient's elevated hemoglobin F level (22%) is indicative of hereditary persistence of fetal hemoglobin. This condition is characterized by the continued presence of fetal hemoglobin into adulthood, leading to a pancellular distribution of hemoglobin F. This explains the high hemoglobin F percentage despite the patient's age. Choice A is incorrect because the elevated hemoglobin F level is not normal in a 7-year-old child. Choice B is incorrect because delta-beta thalassemia typically presents with a different hemoglobin electrophoresis pattern. Choice C is incorrect because delta-beta thalassemia can indeed cause microcytosis due to ineffective erythropoiesis.
Question 3 of 5
A newborn male has severe bleeding after circumcision, resulting in the need for a blood transfusion. You are called to consult on this child, and you diagnose him with severe hemophilia A. Upon taking a family history, you note that no other family members have hemophilia, other bleeding disorders, or a bleeding diathesis. Which of the following is the most likely outcome of genotyping the Factor VIII gene?
Correct Answer: C
Rationale: The correct answer is C: An inversion mutation in the F8 gene will be identified. In hemophilia A, about 50% of cases result from inversion mutations in the F8 gene. In this case, since there is no family history of hemophilia or other bleeding disorders, the most likely scenario is a de novo genetic mutation, such as an inversion mutation. This type of mutation can occur spontaneously and is not inherited from parents. Therefore, genotyping the Factor VIII gene in this newborn male with severe hemophilia A is likely to reveal an inversion mutation as the underlying genetic cause. Choice A is incorrect because the absence of a family history does not rule out the presence of a de novo mutation. Choice B (missense mutation) and Choice D (nonsense mutation) are less likely in hemophilia A compared to inversion mutations. Missense and nonsense mutations are more commonly associated with other genetic conditions or types of hemophilia.
Question 4 of 5
A healthy 17-year-old African American male presents with a thrombosis of the right upper extremity. His past medical history is remarkable only for sickle cell trait. The history is negative for recent risk factors for thrombosis (illness, surgery, immobility). He is the pitcher for his high school baseball team. Imaging confirms anatomical compression/narrowing of the right subclavian vein. Which of the following interventions is most likely to decrease this patient's long-term risk of recurrent thrombosis?
Correct Answer: D
Rationale: The correct answer is D: Resection of right first rib. The patient's presentation with thrombosis of the right upper extremity, anatomical compression/narrowing of the right subclavian vein, and being a high school baseball pitcher suggests Paget-Schroetter syndrome (effort thrombosis). The first rib can compress the subclavian vein in people with certain anatomical variations, leading to thrombosis. Resection of the right first rib (first rib resection) is the definitive treatment for this condition, as it removes the mechanical compression, reducing the risk of recurrent thrombosis. A: Systemic thrombolysis involves using medications to dissolve blood clots throughout the body and is not the first-line treatment for Paget-Schroetter syndrome. B: Catheter-directed thrombolysis is not indicated for anatomical compression/narrowing as seen in this patient. C: Extended anticoagulation with LMWH does not address the underlying mechanical
Question 5 of 5
Iron-refractory iron deficiency anemia (IRIDA) is a rare inherited condition characterized by congenital iron deficiency anemia, poor response to oral iron, and partial but incomplete response to intravenous iron therapy. Which is the genetic mutation associated with IRIDA?
Correct Answer: C
Rationale: Correct Answer: C (TMPRSS6) Rationale: 1. TMPRSS6 gene encodes matriptase-2, a negative regulator of hepcidin, which controls iron absorption. 2. Mutations in TMPRSS6 lead to elevated hepcidin levels, causing iron-refractory iron deficiency anemia. 3. TFR2, H63D, and EPOR are not directly involved in hepcidin regulation or iron absorption. Summary: A (TFR2), B (H63D), and D (EPOR) are not associated with the pathophysiology of IRIDA, which is primarily linked to mutations in the TMPRSS6 gene affecting hepcidin regulation and iron absorption.