Cole Lindsay W, Sidis Yisrael, Zhang ChengKang, Quinton Richard, Plummer Lacey, Pignatelli Duarte, Hughes Virginia A, Dwyer Andrew A, Raivio Taneli, Hayes Frances J, Seminara Stephanie B, Huot Celine, Alos Nathalie, Speiser Phyllis, Takeshita Akira, Van Vliet Guy, Pearce Simon, Crowley William F, Zhou Qun-Yong, Pitteloud Nelly
Reproductive Endocrine Unit of the Department of Medicine, Harvard Reproductive Endocrine Sciences Center, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
J Clin Endocrinol Metab. 2008 Sep;93(9):3551-9. doi: 10.1210/jc.2007-2654. Epub 2008 Jun 17.
Mice deficient in prokineticin 2(PROK2) and prokineticin receptor2 (PROKR2) exhibit variable olfactory bulb dysgenesis and GnRH neuronal migration defects reminiscent of human GnRH deficiency.
We aimed to screen a large cohort of patients with Kallmann syndrome (KS) and normosmic idiopathic hypogonadotropic hypogonadism (IHH) for mutations in PROK2/PROKR2, evaluate their prevalence, define the genotype/phenotype relationship, and assess the functionality of these mutant alleles in vitro.
Sequencing of the PROK2 and PROKR2 genes was performed in 170 KS patients and 154 nIHH. Mutations were examined using early growth response 1-luciferase assays in HEK 293 cells and aequorin assays in Chinese hamster ovary cells.
Four heterozygous and one homozygous PROK2 mutation (p.A24P, p.C34Y, p.I50M, p.R73C, and p.I55fsX1) were identified in five probands. Four probands had KS and one nIHH, and all had absent puberty. Each mutant peptide impaired receptor signaling in vitro except the I50M. There were 11 patients who carried a heterozygous PROKR2 mutation (p.R85C, p.Y113H, p.V115M, p.R164Q, p.L173R, p.W178S, p.S188L, p.R248Q, p.V331M, and p.R357W). Among them, six had KS, four nIHH, and one KS proband carried both a PROKR2 (p.V115M) and PROK2 (p.A24P) mutation. Reproductive phenotypes ranged from absent to partial puberty to complete reversal of GnRH deficiency after discontinuation of therapy. All mutant alleles appear to decrease intracellular calcium mobilization; seven exhibited decreased MAPK signaling, and six displayed decreased receptor expression. Nonreproductive phenotypes included fibrous dysplasia, sleep disorder, synkinesia, and epilepsy. Finally, considerable variability was evident in family members with the same mutation, including asymptomatic carriers.
Loss-of-function mutations in PROK2 and PROKR2 underlie both KS and nIHH.
缺乏前动力蛋白2（PROK2）和前动力蛋白受体2（PROKR2）的小鼠表现出可变的嗅球发育不全和促性腺激素释放激素（GnRH）神经元迁移缺陷，这使人联想到人类GnRH缺乏症。
我们旨在对一大群卡尔曼综合征（KS）患者和嗅觉正常的特发性低促性腺激素性性腺功能减退（IHH）患者进行PROK2/PROKR2突变筛查，评估其患病率，确定基因型/表型关系，并在体外评估这些突变等位基因的功能。
对170例KS患者和154例nIHH患者进行了PROK2和PROKR2基因测序。使用HEK 293细胞中的早期生长反应1-荧光素酶测定法和中国仓鼠卵巢细胞中的水母发光蛋白测定法检查突变。
在5名先证者中鉴定出4个杂合子和1个纯合子PROK2突变（p.A24P、p.C34Y、p.I50M、p.R73C和p.I55fsX1）。4名先证者患有KS，1名患有nIHH，且均未经历青春期。除I50M外，每个突变肽在体外均损害受体信号传导。有11名患者携带杂合子PROKR2突变（p.R85C、p.Y113H、p.V115M、p.R164Q、p.L173R、p.W178S、p.S188L、p.R248Q、p.V331M和p.R357W）。其中，6名患有KS，4名患有nIHH，1名KS先证者同时携带PROKR2（p.V115M）和PROK2（p.A24P）突变。生殖表型从青春期缺失到部分青春期再到治疗中断后GnRH缺乏完全逆转不等。所有突变等位基因似乎都降低了细胞内钙动员；7个表现出丝裂原活化蛋白激酶（MAPK）信号传导降低，6个表现出受体表达降低。非生殖表型包括纤维发育不良、睡眠障碍、联带运动和癫痫。最后，在具有相同突变的家庭成员中，包括无症状携带者，存在明显的变异性。
PROK2和PROKR2的功能丧失突变是KS和nIHH的基础。
