The serum level of anti-Mullerian hormone (AMH), a product from granulosa cells involved in follicle growth, has been shown to correlate tightly with the small antral follicle number (FN) at ultrasonography (U/S) in women who do not have polycystic ovary syndrome (PCOS). Because PCOS is associated with a 2- to 3-fold increase in growing FN, we investigated whether an increased AMH serum level correlates to other hormonal and/or U/S features of PCOS. Serum AMH has been assayed in 104 women (59 symptomatic PCOS, 45 controls) between d 2 and 7 after the last either spontaneous or progestin-induced (in PCOS) menstrual period. Mean serum AMH level was markedly increased in the PCOS group (47.1 +/- 22.9 vs. 20.8 +/- 11.6 pmol/liter in controls; P < 0.0001), an increase in the same order of magnitude as the one of the FN in the 2- to 5-mm range at U/S (12.8 +/- 8.3 vs. 4.8 +/- 1.9; P < 0.0001, respectively). The ratio AMH/FN was similar between the two groups (4.8 +/- 3.4 vs. 4.8 +/- 2.9; P = 0.55). By simple regression, both in PCOS and controls, the AMH level was positively related to the 2- to 5-mm FN at U/S (P < 0.0001 and P < 0.03, respectively), but not to the 6- to 9-mm FN, and was negatively correlated to the serum FSH level (P < 0.02 and P < 0.04, respectively). AMH was also positively related to the serum testosterone and androstenedione levels, in PCOS exclusively (P < 0.0005 and <0.002, respectively). No relationship was found between AMH and age, serum estradiol, inhibin B, and LH levels in both groups. After multiple regression only the 2- to 5-mm FN remained significantly related to AMH in PCOS whereas testosterone, androstenedione, and FSH were no longer. In conclusion, the assay of the serum AMH may represent an important breakthrough in the diagnosis and in the understanding of PCOS. Our data suggest that the increase of AMH serum level in PCOS is the consequence of the androgen-induced excess in small antral FN and that each follicle produces a normal amount of AMH. We hypothesize that an increased AMH tone within the cohort could be involved in the follicular arrest of PCOS, by interacting negatively with FSH at the time of selection.

Pheochromocytomas are neural crest–derived tumors that arise from inherited or sporadic mutations in at least six independent genes. The proteins encoded by these multiple genes regulate distinct functions. We show here a functional link between tumors with VHL mutations and those with disruption of the genes encoding for succinate dehydrogenase (SDH) subunits B (SDHB) and D (SDHD). A transcription profile of reduced oxidoreductase is detected in all three of these tumor types, together with an angiogenesis/hypoxia profile typical of VHL dysfunction. The oxidoreductase defect, not previously detected in VHL-null tumors, is explained by suppression of the SDHB protein, a component of mitochondrial complex II. The decrease in SDHB is also noted in tumors with SDHD mutations. Gain-of-function and loss-of-function analyses show that the link between hypoxia signals (via VHL) and mitochondrial signals (via SDH) is mediated by HIF1α. These findings explain the shared features of pheochromocytomas with VHL and SDH mutations and suggest an additional mechanism for increased HIF1α activity in tumors.

Polycystic ovary syndrome (PCOS) is the main cause of female infertility worldwide and corresponds with a high degree of comorbidities and economic burden. How PCOS is passed on from one generation to the next is not clear, but it may be a developmental condition. Most women with PCOS exhibit higher levels of circulating luteinizing hormone, suggestive of heightened gonadotropin-releasing hormone (GnRH) release, and Anti-Müllerian Hormone (AMH) as compared to healthy women. Excess AMH in utero may affect the development of the female fetus. However, as AMH levels drop during pregnancy in women with normal fertility it was unclear if their levels were also elevated in pregnant women with PCOS. Here, we measured AMH in a cohort of pregnant women with PCOS and control women and found that AMH is significantly more elevated in the former group versus the latter. To determine if the elevation of AMH during pregnancy in women with PCOS is a bystander effect or a driver of the condition in the offspring, we modelled our clinical findings by treating pregnant mice with AMH and followed the neuroendocrine phenotype of their female progeny postnatally. This treatment resulted in maternal neuroendocrine-driven testosterone excess and diminished placental metabolism of testosterone to estradiol, resulting in a masculinization of the exposed female fetus and a PCOS-like reproductive and neuroendocrine phenotype in adulthood. We found that the affected females had persistently hyperactivated GnRH neurons and that GnRH antagonist treatment in the adult female offspring restored their neuroendocrine phenotype to a normal state. These findings highlight a critical role for excess prenatal AMH exposure and subsequent aberrant GnRH receptor signaling in the neuroendocrine dysfunctions of PCOS, while offering a new potential therapeutic avenue to treat the condition during adulthood.

For the definition of PCOM, the former threshold of >12 for FN is no longer valid. A serum AMH >35 pmol/l (or >5 ng/ml) appears to be more sensitive and specific than a FN >19 and should be therefore included in the current diagnostic classifications for PCOS.

VHL, NF-1, c-Ret, and Succinate Dehydrogenase Subunits B and D act on a developmental apoptotic pathway that is activated when nerve growth factor (NGF) becomes limiting for neuronal progenitor cells and requires the EglN3 prolyl hydroxylase as a downstream effector. Germline mutations of these genes cause familial pheochromocytoma and other neural crest-derived tumors. Using an unbiased shRNA screen we found that the kinesin KIF1B␤ acts downstream from EglN3 and is both necessary and sufficient for neuronal apoptosis when NGF becomes limiting. KIF1B␤ maps to chromosome 1p36.2, which is frequently deleted in neural crest-derived tumors including neuroblastomas. We identified inherited loss-of-function KIF1B␤ missense mutations in neuroblastomas and pheochromocytomas and an acquired loss-of-function mutation in a medulloblastoma, arguing that KIF1B␤ is a pathogenic target of these deletions.[Keywords: Apoptosis; kinesin; neuroblastoma; pheochromocytoma; prolyl hydroxylase] Supplemental material is available at http://www.genesdev.org.