PLOD1 and autosomal erythropoietic protoporphyria: The overnight increase in total U-LH-ir-to-U-FSH ratio during sleep was not significantly higher in LPP girls than that in EPP girls, but this increase during overnight sleep was less than 3-fold in all the five early prepubertal girls and more than 1.7-fold in all late prepubertal girls (Fig. 3A).