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. Author manuscript; available in PMC: 2010 Jul 1.
Published in final edited form as: Am J Med Genet A. 2009 Jul;149A(7):1382–1391. doi: 10.1002/ajmg.a.32846

Figure 2.

Figure 2

Plot of clock time (x-axis) versus plasma melatonin concentration (y-axis) showing the normal pattern of melatonin rise in the evening and nadir in the middle of the day for our patient at age 18 years old. This profile was obtained on the third admission and is nearly identical to those obtained on the first two admissions. It illustrates the peak onset of melatonin occurs at about 2200 hours. It also shows that giving a pulse of bright light (indicated by the rectangles) temporarily inhibits melatonin secretion as shown by the drop in melatonin concentration, which rebounds after the light is stopped. This pattern of inhibition of melatonin secretion by light is typical and further illustrates that melatonin secretion and response to light is not abnormal in our patient.