TFM - testicular feminisation syndrome

- - 2nd ex : if girls hasn't reached puberty by 14 (12 is western average), you get worried, go to doctor and informs you you have a boy that has ''' TFM: testicular feminisation syndrome. (genetically male at levels of chromosomes: XX) They have testicles that never descended from stomach, but made lots of testosterone + have female  phenotype ''' (female in appearance: female in external genitalia but not internal: a vagina that goes nowhere bc no ovaries but testicles inside) (wikipedia: phenotype inseamna composite of an organism's observable characteristics or traits, such as its morphology, development, biochemical or physiological properties, phenology, behavior, and products of behavior (such as a bird's nest). So we have a simple mutation that changes shape of the androgen/testosterone receptor -> doesn't matter how much testosterone flows around the target cells don't listen. (sapolsky lecture 4 molecular genetics)