Identification of the hormone kisspeptin in amniotic fluid

Kisspeptin is the product of the KISS1 1 (KiSS-1 metastasis-suppressor) gene and is the ligand for the G-protein–coupled receptor, now known as the KISS1 receptor (KISS1R)2 (1). Both kisspeptin and KISS1R play a crucial role in the regulation of reproduction and puberty(1). The KISS1 gene encodes a precursor peptide of 145 amino acid residues, which undergoes proteolytic processing to generate kisspeptins 10, 13, 14, and 54(1). These peptides all share the common C-terminal decapeptide necessary for receptor activation(1). Inactivating mutations in the human KISS1R (KISS1 receptor) gene cause hypogonadotropic hypogonadism(1). During pregnancy, circulating plasma kisspeptin concentrations rise by 7000-fold in the third trimester, compared with the concentrations in nonpregnant women(2). Plasma markers that are altered during pregnancy, such as β human chorionic gonadotropin, have been used as markers in amniotic fluid and in certain cases may be used as markers to predict fetal outcome. Kisspeptin, however, has not previously been identified in amniotic fluid. The aim of this study was to determine whether kisspeptin is present in amniotic fluid. After obtaining ethics approval (Hammersmith and Queen Charlotte’s and Chelsea Hospitals Research Ethics Committee no. 06/Q0406/12), we recruited 32 volunteers scheduled to undergo diagnostic amniocentesis at Queen Charlotte’s and Chelsea Hospital, London, UK. Indications …