Neuropathy target esterase activity defines phenotypes among PNPLA6 disorders.

Biallelic pathogenic variants in the PNPLA6 gene cause a broad spectrum of disorders leading to gait disturbance, visual impairment, anterior hypopituitarism and hair anomalies. PNPLA6 encodes neuropathy target esterase (NTE), yet the role of NTE dysfunction on affected tissues in the large spectrum of associated disease remains unclear. We present a systematic evidence-based review of a novel cohort of 23 new patients along with 95 reported individuals with PNPLA6 variants that implicate missense variants as a driver of disease pathogenesis. Measuring esterase activity of 46 disease-associated and 20 common variants observed across PNPLA6-associated clinical diagnoses unambiguously reclassified 36 variants as pathogenic and 10 variants as likely pathogenic, establishing a robust functional assay for classifying PNPLA6 variants of unknown significance. Estimating the overall NTE activity of affected individuals revealed a striking inverse relationship between NTE activity and the presence of retinopathy and endocrinopathy. This phenomenon was recaptured in vivo in an allelic mouse series, where a similar NTE threshold for retinopathy exists. Thus, PNPLA6 disorders, previously considered allelic, are a continuous spectrum of pleiotropic phenotypes defined by an NTE genotype:activity:phenotype relationship. This relationship, and the generation of a preclinical animal model, pave the way for therapeutic trials, using NTE as a biomarker.

A systematic review and meta-analysis of cell-free DNA testing for detection of fetal sex chromosome aneuploidy.

OBJECTIVES: The aim was to determine the accuracy of cell-free DNA testing (cfDNA) for detecting sex chromosome aneuploidies (SCA) in singleton pregnancies. METHODS: A systematic review and meta-analysis was performed to assess cfDNA accuracy for prenatal detection of 45,X, 47,XXY, 47,XXX and 47,XYY. Inclusion was restricted to studies published between January 2010 and December 2021 reporting both cfDNA and confirmatory diagnostic test results. RESULTS: For 45,X, the sensitivity was 98.8% (95%CI 94.6%-100%), specificity 99.4% (95%CI 98.7%-99.9%) and positive predictive value (PPV) 14.5% (95%CI 7.0%-43.8%). For 47,XXY, the sensitivity was 100% (95%CI 99.6%-100%), specificity 100% (95%CI 99.9%-100%) and PPV 97.7% (95%CI 78.6%-100%). For 47,XXX, the sensitivity was 100% (95%CI 96.9%-100%), specificity 99.9% (95%CI 99.7%-100%) and PPV 61.6% (95%CI 37.6%-95.4%). For 47,XYY, the sensitivity was 100% (95%CI 91.3%-100%), specificity 100% (95% CI 100%-100%) and PPV 100% (95%CI 76.5%-100%). All four SCAs had estimated negative predictive values (NPV) exceeding 99.99%, though false negatives were reported. CONCLUSIONS: This analysis suggests that cfDNA is a reliable screening test for SCA, though both false negatives and false positives were reported. These estimates of test performance are derived from pregnancies at high pretest risk for aneuploidy, limiting the generalisability to average risk pregnancies.

In Utero Fetal Therapy: Stem Cells, Cell Transplantation, Gene Therapy, and CRISPR-Cas9.

In utero fetal therapy offers the opportunity to prevent and treat diseases with a cellular or genetic basis. Components of successful fetal treatment include isolation of a replacement cell population, in utero stem cell transplantation, cell engraftment with fetal immune tolerance, and ongoing cell function. Fetal gene therapy with CRISPR-Cas9 represents an exciting potential therapy for genetic diseases not amenable to gene supplementation via adenoviral vector transduction. These fetal therapies have unique ethical and safety considerations. Clinical trials for in utero cell therapy are underway, as additional discoveries in stem cell biology and gene therapy move closer to clinical translation.

Blasts from the past: is morphology useful in PGT-A tested and untested frozen embryo transfers?

RESEARCH QUESTION: Day of cryopreservation, inner cell mass (ICM) grade, trophectoderm grade and blastocyst expansion grade have been associated with differences in live birth rate in frozen embryo transfer (FET) cycles. This study sought to examine the likelihood of live birth and whether the morphological grade of the blastocyst is more or equally useful in FET cycles among preimplantation genetic testing for aneuploidies (PGT-A) tested and untested blastocysts. DESIGN: This was a retrospective cohort study of 6271 vitrified-warmed, autologous, single-embryo transfer cycles among patients undergoing IVF from July 2013 to December 2017 at a single, university-affiliated infertility practice. The primary outcome was live birth, calculated by generalized estimating equations. RESULTS: Among PGT-A tested embryos, inferior ICM grade was associated with a lower chance of live birth (ICM grade B versus A: adjusted risk ratio [aRR] 0.91, 95% confidence interval [CI] 0.84-0.99). Among untested blastocysts there was a lower live birth rate in blastocysts cryopreserved on day 6 versus day 5 (aRR 0.87, 95% CI 0.78-0.96), and those with inferior pre-vitrification trophectoderm grade (trophectoderm grade B versus A: aRR 0.86, 95% CI 0.79-0.94). Blastocysts with a higher pre-vitrification expansion grade (pre-vitrification expansion grade 5 versus 4: aRR 1.1, 95% CI 1.01-1.2) were associated, but ICM grade was not associated (ICM grade B versus A: aRR 0.93, 95% CI 0.86-1.02), with chance of live birth. CONCLUSIONS: Among PGT-A untested blastocysts, assessing embryo quality by day of cryopreservation, trophectoderm grade and expansion grade may help to identify embryos with the highest likelihood of live birth. Identifying euploid embryos by PGT-A appears to homogenize the cohort, making blastocyst morphological grade and day of cryopreservation less important.

Adoption of enhanced recovery after laparotomy in gynecologic oncology.

INTRODUCTION: Enhanced recovery after surgery (ERAS) pathways combine a comprehensive set of peri-operative practices that have been demonstrated to hasten patient post-operative recovery. We aimed to evaluate the adoption of ERAS components and assess attitudes towards ERAS among gynecologic oncologists. METHODS: We developed and administered a cross-sectional survey of attending, fellow, and resident physicians who were members of the Society of Gynecologic Oncology in January 2018. The χ2 test was used to compare adherence to individual components of ERAS. RESULTS: There was a 23% survey response rate and we analyzed 289 responses: 79% were attending physicians, 57% were from academic institutions, and 64% were from institutions with an established ERAS pathway. Respondents from ERAS institutions were significantly more likely to adhere to recommendations regarding pre-operative fasting for liquids (ERAS 51%, non-ERAS 28%; p<0.001), carbohydrate loading (63% vs 16%; p<0.001), intra-operative fluid management (78% vs 32%; p<0.001), and extended duration of deep vein thrombosis prophylaxis for malignancy (69% vs 55%; p=0.003). We found no difference in the use of mechanical bowel preparation, use of peritoneal drainage, or use of nasogastric tubes between ERAS and non-ERAS institutions. Nearly all respondents (92%) felt that ERAS pathways were safe. DISCUSSION: Practicing at an institution with an ERAS pathway increased adoption of many ERAS elements; however, adherence to certain guidelines remains highly variable. Use of bowel preparation, nasogastric tubes, and peritoneal drainage catheters remain common. Future work should identify barriers to the implementation of ERAS and its components.

Neuropathy target esterase activity predicts retinopathy among PNPLA6 disorders.

Biallelic pathogenic variants in the PNPLA6 gene cause a broad spectrum of disorders leading to gait disturbance, visual impairment, anterior hypopituitarism, and hair anomalies. PNPLA6 encodes Neuropathy target esterase (NTE), yet the role of NTE dysfunction on affected tissues in the large spectrum of associated disease remains unclear. We present a clinical meta-analysis of a novel cohort of 23 new patients along with 95 reported individuals with PNPLA6 variants that implicate missense variants as a driver of disease pathogenesis. Measuring esterase activity of 46 disease-associated and 20 common variants observed across PNPLA6 -associated clinical diagnoses unambiguously reclassified 10 variants as likely pathogenic and 36 variants as pathogenic, establishing a robust functional assay for classifying PNPLA6 variants of unknown significance. Estimating the overall NTE activity of affected individuals revealed a striking inverse relationship between NTE activity and the presence of retinopathy and endocrinopathy. This phenomenon was recaptured in vivo in an allelic mouse series, where a similar NTE threshold for retinopathy exists. Thus, PNPLA6 disorders, previously considered allelic, are a continuous spectrum of pleiotropic phenotypes defined by an NTE genotype:activity:phenotype relationship. This relationship and the generation of a preclinical animal model pave the way for therapeutic trials, using NTE as a biomarker.