Source / episode info
- **Episode:**187
- **Title:**Divine Intervention Episode 187 – USMLE Step 2CK Rapid Review Series 25.
- **Published:**2019-11-27
- Source:Episode page
One-liner
This rapid review covers critical high-yield topics including immunodeficiencies (Hyper-IgM, CGD, LAD), genetic syndromes involving genomic imprinting (Prader-Willi/Angelman), drug toxicities from anti-psychotics (Clozapine, Quetiapine), cardiovascular management of heart failure, and neuromuscular disorders like Lambert-Eaton syndrome.
High-yield summary
- Hyper-IgM Syndrome: Caused by defects in class switching, often due to impaired CD40/CD40L interaction; results in low IgG, IgA, and IgE, but normal or elevated IgM.
- CGD: X-linked recessive disorder affecting neutrophils due to NADPH oxidase deficiency; treated with Interferon gamma.
- DiGeorge Syndrome: Caused by deletion of chromosome 22q11; leads to T-cell immunodeficiency (due to pharyngeal pouch defects) and hypocalcemia/hypoparathyroidism.
- Prader-Willi/Angelman Syndromes: Both involve genomic imprinting on chromosome 15; PWS is associated with paternal gene loss, while AS is associated with maternal gene loss.
- Heart Failure Management: Key drugs include ACE inhibitors, ARBs, Mineralocorticoid Receptor Antagonists (MRAs), and Beta-blockers; Spironolactone carries a risk of gynecomastia due to androgen receptor antagonism.
- Anti-psychotic Toxicities: Clozapine -> Myocarditis/Dilated Cardiomyopathy; Quetiapine -> Cataract ("Quinaurex"); Olanzapine -> Metabolic Syndrome.
Learning objectives
- Identify the specific cell type affected in major immunodeficiency syndromes (e.g., neutrophils in CGD, T cells in DiGeorge).
- Differentiate between genetic disorders involving genomic imprinting and uniparental disomy (PWS vs Angelman).
- Recognize the clinical manifestations and associated drug toxicities of anti-psychotic medications.
- Understand the pathophysiology and management principles for heart failure using RAAS inhibitors and beta-blockers.
- Correlate specific physical exam findings or lab results with neuromuscular junction disorders (e.g., LEMS, HAE).