TY - CHAP M1 - Book, Section TI - PEDIATRIC LABORATORY TESTING FOR SPECIFIC ENDOCRINE CONDITIONS A1 - Nakamoto, Jon A2 - Jones, Patricia M. A2 - Dietzen, Dennis J. A2 - Haymond, Shannon A2 - Bennett, Michael J. PY - 2017 T2 - Pediatric Laboratory Medicine AB - LEARNING OBJECTIVESExplain the basic pathophysiology of congenital adrenal hyperplasia (CAH).Name at least one pre-analytical and one analytical factor that can lead to a false positive diagnosis of 21-hydroxylase deficiency (21OHD) based on measurement of 17-hydroxyprogesterone (17OHP).Discuss the methodologic advantages of steroid assays (immunoassay or mass spectrometry) that involve upfront sample purification by extraction and chromatography.Define the term “gene conversion” and describe its importance in the etiology of 21OHD.State the rationale for newborn screening for classical 21-hydroxylase deficiency (21OHD).Outline the essential steps to the evaluation of a short or poorly-growing child.Understand why random measurement of growth hormone is rarely useful.Explain how biological and analytical variability contribute to both low diagnostic sensitivity and specificity of laboratory testing for growth hormone deficiency.Name at least two reasons why different growth hormone assays can yield widely different results from the same patient sample.Identify the difficulties in establishing reference intervals for insulin-like growth factor I (IGF-I). SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accesspediatrics.mhmedical.com/content.aspx?aid=1146626093 ER -