This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sex Intersexuality, Subject name: Gynaecology & Obstetrics
[{'content': "Young male presents with delayed puberty with decreased FSH, LH, and testosterone. Which of the following is NOT possible? \nSelect and explain. \nA. Kallmann syndrome, B. Klinefelter's syndrome, C. Constitutional delay, D. DAX-1 gene mutation", 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is b, i.e Klinefelter's syndromeRef: Leon Speroff 7th/ed, p404-407* Decrease in serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone indicates that this is a case of hypogonadotropic hypogonadism.* Hypogonadism resulting from hypothalamic or pituitary defects is called as hypogonadotropic hypogonadism or central hypogonadism. Examples of hypothalamic defects include Kallmann syndrome. Examples of pituitary defects include hypopituitarism. DAX-1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1) is a nuclear receptor protein. Mutations in this gene result in both X-linked congenital adrenal hypoplasia and hypogonadotropic hypogonadism.* Hypogonadism which results from defects of the gonads is called as primary hypogonadism/hypergonadotropic hypogonadism. Examples include Klinefelter syndrome, mumps, varicocele, etc.In Klinefelters = Testosterone is decreased, which results in increase in LH and FSH.", 'role': 'assistant'}]