5α reductase deficiency leading to ↑ LH

[LichenPlanus]

I was doing a USMLE-Rx question and it stated (along with FA pg 579) that 5α reductase deficiency leads to ↑ LH. Also, FA states Testosterone and estrogen are elevated...

Why would you not get ↑ testosterone and ↓ LH via negative feedback? this isn't making any sense to me...

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[pathologyDO]

In FA 2015 edition, page 579 they say that in 5-alpha reductase deficiency there will be normal estrogen/testosterone levels. They say that during puberty, when there is a spike in the testosterone, you will see masculinization. They also say that LH will be normal or increased, and why it would be increased I am not sure. Good question !

 

[aspiringmd1015]

lets see, DHT is responsible for PPS formation right, so bc they dont have DHT, they have ambig genitilia, but with puberty the exact unknown mechanism of puberty causing increased fsh and LH will cause increased testo formation, which will then lead to masculinization of the male, also i believe DHT also plays a role in feedback, so no DHT you might see a little bump up of LH. But at puberty, theres unkknown reasons for why your hypothalamus starts making gnrh, so its puberty related i guess.