1. Hormone Laboratory, Department of Medical Biochemistry and Biochemical Endocrinology and Metabolism Work Group, Oslo University Hospital , Oslo 0424 , Norway
2. Department of Medical Genetics, Oslo University Hospital , Oslo 0424 , Norway
3. Institute of Clinical Medicine, University of Oslo , Oslo 0316 , Norway
4. Department of Endocrinology, Oslo University Hospital , Oslo 0424 , Norway
5. Department of Pediatric Medicine, Oslo University Hospital , Oslo 0424 , Norway