Neurodegenerative Diseases USMLE Step 1 Practice Question
A 2-year-old boy presents with infantile spasms and developmental regression. Vital signs show HR 110 bpm, BP 95/58 mmHg, RR 22/min, temp 37.2°C, SpO2 98%. Physical examination reveals facial angiofibromas and multiple hypopigmented ash-leaf spots on the trunk. Brain MRI demonstrates subependymal nodules and cortical tubers. Serum glucose and electrolytes are normal. There is no family history of seizures. Which intracellular signaling pathway is dysregulated in this disorder?
Answer choices
- ANF kappa B activation by Epstein Barr virus
- BMAP kinase signaling through RAS activation
- CWnt beta catenin signaling due to APC loss
- DBCR ABL tyrosine kinase signaling
- EmTOR signaling due to loss of hamartin tuberin functionCorrect answer
- FPI3K-AKT hyperactivation due to PTEN tumor suppressor loss
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