Prenatal diagnosis of cerebro-oculo-facio-skeletal syndrome: Report of three fetuses and review of the literature.

Cerebro-oculo-facio-skeletal syndrome (COFS) is a rare autosomal recessive neurodegenerative disease belonging to the family of DNA repair disorders, characterized by microcephaly, congenital cataracts, facial dysmorphism and arthrogryposis. Here, we describe the detailed morphological and microscopic phenotype of three fetuses from two families harboring ERCC5/XPG likely pathogenic variants, and review the five previously reported fetal cases. In addition to the classical features of COFS, the fetuses display thymus hyperplasia, splenomegaly and increased hematopoiesis. Microencephaly is present in the three fetuses with delayed development of the gyri, but normal microscopic anatomy at the supratentorial level. Microscopic anomalies reminiscent of pontocerebellar hypoplasia are present at the infratentorial level. In conclusion, COFS syndrome should be considered in fetuses when intrauterine growth retardation is associated with microcephaly, arthrogryposis and ocular anomalies. Further studies are needed to better understand XPG functions during human development.

Correlations of quantitative MRI metrics with myelin basic protein (MBP) staining in a murine model of demyelination.

Myelin imaging in the central nervous system is essential for monitoring pathologies involving white matter alterations. Various quantitative MRI protocols relying on the modeling of the interactions of water protons with myelinated tissues have shown sensitivities in case of myelin disruption. Some extracted model parameters are more sensitive to demyelination, such as the bound pool fraction (f) in quantitative magnetization transfer imaging (qMTI), the radial diffusivity in diffusion tensor imaging (DTI), and the myelin water fraction (MWF) in myelin water imaging (MWI). A 3D ultrashort echo time (UTE) sequence within an appropriate water suppression condition (Diff-UTE) is also considered for the direct visualization of the myelin semi-solid matrix (Diff-UTE normalized signal; rSPF). In this paper, we aimed at assessing the sensitivities and correlations of the parameters mentioned above to an immuno-histological study of the myelin basic protein (MBP) in a murine model of demyelination at 7 T. We demonstrated a high sensitivity of the MRI metrics to demyelination, and strong Spearman correlations in the corpus callosum between histology, macromolecular proton fraction (ρ>0.87) and Diff-UTE signal (ρ>0.76), but moderate ones with radial diffusivity and MWF (|ρ|<0.70).

Bardet-Biedl syndrome: Antenatal presentation of forty-five fetuses with biallelic pathogenic variants in known Bardet-Biedl syndrome genes.

Bardet-Biedl syndrome (BBS) is an emblematic ciliopathy associated with retinal dystrophy, obesity, postaxial polydactyly, learning disabilities, hypogonadism and renal dysfunction. Before birth, enlarged/cystic kidneys as well as polydactyly are the hallmark signs of BBS to consider in absence of familial history. However, these findings are not specific to BBS, raising the problem of differential diagnoses and prognosis. Molecular diagnosis during pregnancies remains a timely challenge for this heterogeneous disease (22 known genes). We report here the largest cohort of BBS fetuses to better characterize the antenatal presentation. Prenatal ultrasound (US) and/or autopsy data from 74 fetuses with putative BBS diagnosis were collected out of which molecular diagnosis was established in 51 cases, mainly in BBS genes (45 cases) following the classical gene distribution, but also in other ciliopathy genes (6 cases). Based on this, an updated diagnostic decision tree is proposed. No genotype/phenotype correlation could be established but postaxial polydactyly (82%) and renal cysts (78%) were the most prevalent symptoms. However, autopsy revealed polydactyly that was missed by prenatal US in 55% of the cases. Polydactyly must be carefully looked for in pregnancies with apparently isolated renal anomalies in fetuses.

Estrogen receptor-α is required for the osteogenic response to mechanical loading in a ligand-independent manner involving its activation function 1 but not 2.

Estrogen receptor-α (ERα) is crucial for the adaptive response of bone to loading but the role of endogenous estradiol (E2) for this response is unclear. To determine in vivo the ligand dependency and relative roles of different ERα domains for the osteogenic response to mechanical loading, gene-targeted mouse models with (1) a complete ERα inactivation (ERα(-/-) ), (2) specific inactivation of activation function 1 (AF-1) in ERα (ERαAF-1(0) ), or (3) specific inactivation of ERαAF-2 (ERαAF-2(0) ) were subjected to axial loading of tibia, in the presence or absence (ovariectomy [ovx]) of endogenous E2. Loading increased the cortical bone area in the tibia mainly as a result of an increased periosteal bone formation rate (BFR) and this osteogenic response was similar in gonadal intact and ovx mice, demonstrating that E2 (ligand) is not required for this response. Female ERα(-/-) mice displayed a severely reduced osteogenic response to loading with changes in cortical area (-78% ± 15%, p < 0.01) and periosteal BFR (-81% ± 9%, p < 0.01) being significantly lower than in wild-type (WT) mice. ERαAF-1(0) mice also displayed a reduced response to mechanical loading compared with WT mice (cortical area -40% ± 11%, p < 0.05 and periosteal BFR -41% ± 8%, p < 0.01), whereas the periosteal osteogenic response to loading was unaffected in ERαAF-2(0) mice. Mechanical loading of transgenic estrogen response element (ERE)-luciferase reporter mice did not increase luciferase expression in cortical bone, suggesting that the loading response does not involve classical genomic ERE-mediated pathways. In conclusion, ERα is required for the osteogenic response to mechanical loading in a ligand-independent manner involving AF-1 but not AF-2.

Liver receptor homolog 1 is essential for ovulation.

Female fertility requires normal ovarian follicular growth and ovulation. The nuclear receptor liver receptor homolog 1 has been implicated in processes as diverse as bile acid metabolism, steroidogenesis, and cell proliferation. In the ovary, Lrh1 is expressed exclusively in granulosa and luteal cells. Using somatic targeted mutagenesis, we show that mice lacking Lrh1 in granulosa cells are sterile, due to anovulation. The preovulatory stimulus fails to elicit cumulus expansion, luteinization, and follicular rupture in these mice. Multiple defects, including severely reduced transactivation of the Lrh1 target gene, nitric oxide synthase 3, leads to increased intrafollicular estradiol levels in the absence of Lrh1. This further causes dysfunction of prostaglandin and hyaluronic acid cascades and interrupts cumulus expansion. Lack of Lrh1 also interferes with progesterone synthesis because of failure of normal expression of the Lrh1 targets, steroidogenic acute regulatory protein and cytochrome P450 side-chain cleavage. In addition, expression of extracellular matrix proteases essential for ovulation is compromised. These results demonstrate that Lrh1 is a regulator of multiple mechanisms essential for maturation of ovarian follicles and for ovulation. Lrh1 is therefore a key modulator of female fertility and a potential target for contraception.