29. An 18 year old girl presented to the GP with h/o 4 months amenorrhea. She gave h/o 15 kg weight loss in the previous 4 months .Her examination is normal. Her laboratory investigations show the following—LH 0.3miu/l (low),FSH 0.2iu/l (low),prolactin 400 mu/l,BHCG—0iu/l,TSH 1.5 miu/l,T4 -200 nmol/l,T3- 2nmol/l. What could be the probable cause?