A 7-year-old girl presents with vaginal bleeding, café au lait macules with irregular borders, and polyostotic fibrous dysplasia on skeletal survey. Vital signs show BP 105/68, HR 88, RR 20, Temp 37.2°C, SpO2 98% on room air. She denies abdominal pain. Laboratory studies reveal elevated 17-hydroxyprogesterone level. She takes no chronic medications. Which of the following best explains her clinical presentation?
- A)Mutation causing androgen receptor insensitivity
- B)Trinucleotide repeat expansion in the FMR1 gene
- C)Deletion of the paternal chromosome 15q11 region
- D)Loss of function mutation in the RET proto oncogene
- E)Activating mutation of Gs alpha causing endocrine hyperfunctionGABARITO
Explicação
McCune Albright syndrome is caused by a somatic activating mutation of Gs alpha. This leads to autonomous endocrine activation, classically precocious puberty, café au lait spots, and fibrous dysplasia. Because the mutation is somatic mosaic, the phenotype is ... Ver explicação completa e trilha adaptativa →