SCN3A-Related Neurodevelopmental Disorder: A Spectrum of Epilepsy and Brain Malformation.

OBJECTIVE: Pathogenic variants in SCN3A, encoding the voltage-gated sodium channel subunit Nav1.3, cause severe childhood onset epilepsy and malformation of cortical development. Here, we define the spectrum of clinical, genetic, and neuroimaging features of SCN3A-related neurodevelopmental disorder. METHODS: Patients were ascertained via an international collaborative network. We compared sodium channels containing wild-type versus variant Nav1.3 subunits coexpressed with ß1 and ß2 subunits using whole-cell voltage clamp electrophysiological recordings in a heterologous mammalian system (HEK-293T cells). RESULTS: Of 22 patients with pathogenic SCN3A variants, most had treatment-resistant epilepsy beginning in the first year of life (16/21, 76%; median onset, 2 weeks), with severe or profound developmental delay (15/20, 75%). Many, but not all (15/19, 79%), exhibited malformations of cortical development. Pathogenic variants clustered in transmembrane segments 4 to 6 of domains II to IV. Most pathogenic missense variants tested (10/11, 91%) displayed gain of channel function, with increased persistent current and/or a leftward shift in the voltage dependence of activation, and all variants associated with malformation of cortical development exhibited gain of channel function. One variant (p.Ile1468Arg) exhibited mixed effects, with gain and partial loss of function. Two variants demonstrated loss of channel function. INTERPRETATION: Our study defines SCN3A-related neurodevelopmental disorder along a spectrum of severity, but typically including epilepsy and severe or profound developmental delay/intellectual disability. Malformations of cortical development are a characteristic feature of this unusual channelopathy syndrome, present in >75% of affected individuals. Gain of function at the channel level in developing neurons is likely an important mechanism of disease pathogenesis. ANN NEUROL 2020;88:348-362.

Inborn errors in RNA polymerase III underlie severe varicella zoster virus infections.

Varicella zoster virus (VZV) typically causes chickenpox upon primary infection. In rare cases, VZV can give rise to life-threatening disease in otherwise healthy people, but the immunological basis for this remains unexplained. We report 4 cases of acute severe VZV infection affecting the central nervous system or the lungs in unrelated, otherwise healthy children who are heterozygous for rare missense mutations in POLR3A (one patient), POLR3C (one patient), or both (two patients). POLR3A and POLR3C encode subunits of RNA polymerase III. Leukocytes from all 4 patients tested exhibited poor IFN induction in response to synthetic or VZV-derived DNA. Moreover, leukocytes from 3 of the patients displayed defective IFN production upon VZV infection and reduced control of VZV replication. These phenotypes were rescued by transduction with relevant WT alleles. This work demonstrates that monogenic or digenic POLR3A and POLR3C deficiencies confer increased susceptibility to severe VZV disease in otherwise healthy children, providing evidence for an essential role of a DNA sensor in human immunity.

Characterization of a recurrent poor-quality embryo morphology phenotype and zygote transfer as a rescue strategy.

Some patients in IVF programmes repeatedly display an abnormal embryonic development characterized as soon as day 2 post fertilization by a high rate (>60%) of highly fragmented embryos (⩾40% of cytoplasmic fragments) leading to recurrent IVF failures. This study postulated that, for various maternal reasons, some embryos were unable to withstand the in-vitro environment and an early pronucleate-stage transfer was proposed to these couples. Fifty-three patients with recurrent IVF failures (a mean of 2.8±1.0 previous attempts) characterized by low embryonic quality (a mean of 62.7% of the embryos with extended fragmentation) were included this transfer protocol. As in previous cycles, the mean number of oocytes retrieved and the fertilization rate were normal. The mean number of zygotes per transfer was 2.24. Fourteen clinical pregnancies were obtained, representing a pregnancy rate and a delivery rate per oocyte retrieval of 26.4% and 18.9%, respectively. Recurrent heavy and early embryo fragmentation in vitro characterizes around 3% of IVF couples and leads to lack of transfer or implantation failure. These data on fresh zygote transfers are encouraging and may provide a valid alternative solution for some of these patients. Some patients in IVF programmes repeatedly display an abnormal embryonic development characterized as soon as day 2 post fertilization by a high rate of highly fragmented embryos, leading to recurrent IVF failures. We hypothesized that, for various reasons, some embryos were unable to withstand the in-vitro environment and an early pronucleate stage transfer was proposed to these couples. Fifty-three patients with recurrent IVF failures characterized by low embryonic quality were included in this transfer protocol. As in previous cycles, the mean number of oocytes retrieved and the fertilization rate were normal. The mean number of zygotes per transfer was 2.24. Fourteen clinical pregnancies were obtained, representing a pregnancy rate and a delivery rate per oocyte retrieval of 26.4% and 18.9%, respectively. Recurrent early and heavy embryo fragmentation in vitro characterizes around 3% of IVF couples and leads to lack of transfer or implantation failure. Our data on fresh zygote transfers are encouraging and may provide a valid alternative solution for these patients.

Use of mifepristone to ripen the cervix and induce labor in term pregnancies.

OBJECTIVE: This study was undertaken to determine the efficacy of mifepristone for ripening the cervix and inducing labor in term pregnancies. STUDY DESIGN: In a double-blind placebo-controlled dose-finding study, 346 women received 50, 100, 200, 400, or 600 mg of mifepristone or placebo. The main endpoint for efficacy was the number of patients in whom labor occurred between 12 and 45 and 54 hours after treatment or who had a Bishop score 6 or greater. Maternal and fetal tolerability was also studied. RESULTS: No significant efficacy was observed whatever the dose of mifepristone. Mifepristone was well tolerated by the mother and fetus. CONCLUSION: Mifepristone, at doses up to 600 mg, does not induce labor within 54 hours in patients with unfavourable cervical status.

Fetal toxicity of valsartan and possible reversible adverse side effects.

BACKGROUND: Published cases suggest that the use of angiotensin II receptor antagonists is fetotoxic during the third trimester, but not in early pregnancy. CASE: We report a case in which the adverse fetal effect of angiotensin II receptor antagonist treatment was reversed. A woman with chronic hypertension was treated with valsartan until gestation week (GW) 20, when a complete anhydramnios was observed. Six days after interruption of the treatment, amniotic fluid reappeared. It reached a normal level at GW 23.5. The plasmatic creatinine level and the renal ultrasound examination were within normal limits at the six-month follow-up. CONCLUSIONS: Whereas angiotensin-II-receptor antagonist generates a severe renal toxicity, this case suggests that, at least in the first half of pregnancy, these effects can be reversed.

[Recurrent miscarriage]. / Echecs répétés de grossesse.

Repetitive spontaneous first trimester miscarriage as well as second and third trimester in utero fetal death are considered as recurrent pregnancy losses. They represent 1% of all pregnancies. Repetitive fetal loss with alive fetus should also be counted as such. An explanation is found for less than 50% of such patients. Most recurrent first trimester fetal losses are of chromosomal, hormonal, immunological, uterine or environmental origin. The most frequent causes for in utero fetal death are renovascular syndromes, hormonal or immunological pathologies, hereditary thrombophilias, red cell or platelet allo-immunisation and chromosomal anomalies. Second trimester miscarriage is generally due to a cervical incompetence, uterine malformations or infections.