All the following are featurof Von Hippel-Lindau (VHL) disease EXCEPT

Correct Answer: D

Rationale: VHL, incidence ~1:36,000 , has ~50% de novo mutations , and featurspinal hemangioblastomas and pheochromocytomas . Renal carcinoma , not listed, is the most common cause of death, not pheochromocytoma, which is frequent but less lethal. Misinterpreting frequent for fatal makes D the intended exception and correct answer, aligning with VHLs mortality profile.

Correct Answer: B

Rationale: Benign familial megalencephaly is the most common anatomic megalencephaly cause, a non-syndromic, inherited large head size without neurologic deficits. Sotos , Simpson-Golabi-Behmel , fragile X , and Weaver are rarer syndromic causwith additional features. Bs frequency and benign nature make it the correct answer.

Correct Answer: D

Rationale: Prolonged febrile seizurpost-vaccination with encephalopathy often reveal Dravet syndrome , a severe SCN1A-related epilepsy misdiagnosed as vaccine injury. GEFS+ , temporal lobe epilepsy , and myoclonic-astatic seizurare less common in this context. Dravets early onset and severity make D the correct answer.

Correct Answer: B

Rationale: Valproic acid causweight gain and alopecia via metabolic and hormonal effects (e.g., insulin resistance, hair follicle disruption). Primidone , oxcarbazepine , lamotrigine , and acetazolamide lack this profile rash or sedation dominate instead. Valproatunique side effects make B the correct answer.

Correct Answer: C

Rationale: Subtle seizure.g., eye deviation, apnea often lack EEG correlatin neonatdue to immature cortex and subcortical origins, per Volpe. Focal clonic , tonic , spasms , and myoclonic typically show discharges. Subtldissociation makes C the correct answer.