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Arthrogryposis describes the presence of multiple joint-contractures. Clinical severity of this phenotype is variable, and more than 400 causative genes have been proposed. Among these, ERGIC1 is a recently reported candidate encoding a putative transmembrane protein of the ER-Golgi interface. Two homozygous missense variants have been reported in patients with relatively mild non-syndromic arthrogryposis. In a consanguineous family with two affected siblings presenting congenital arthrogryposis and some facial dysmorphism we performed prenatal array-CGH, postnatal targeted exome and genome sequencing. Genome sequencing identified a homozygous 22.6 Kb deletion encompassing the promoter and first exon of ERGIC1. mRNA quantification showed the complete absence of ERGIC1 expression in the two affected siblings and a decrease in heterozygous parents. Our observations validate the pathogenic role of ERGIC1 in congenital arthrogryposis and demonstrate that complete loss of function causes a relatively mild phenotype. These findings will contribute to improve genetic counseling of ERGIC1 mutations., (© 2021 The Authors. Clinical Genetics published by John Wiley & Sons Ltd.)

Aims of the Study: The European Society of Medical Oncology (ESMO) recommends that countries should have reference centres to provide adequate diagnosis and treatment of gestational trophoblastic disease. A trophoblastic disease centre in the French-speaking part of Switzerland was inaugurated in 2009. The objectives of this study were to report the activity of the centre during the last 10 years and analyse gestational trophoblastic disease outcomes., Methods: This was a retrospective study with data collected from all cases of gestational trophoblastic disease referred to the centre from 2009 to 2018. All histological specimens as well as data for treatment and follow-up of gestational trophoblastic disease and neoplasia were reviewed. Clinical features, including age, prognostic score and International Federation of Gynecology and Obstetrics (FIGO) stages (in the case of gestational trophoblastic neoplasia), human chorionic gonadotropin (hCG) follow-up, treatment and outcome were reported., Results: The centre registered 354 patients, and these patients presented 156 cases of partial hydatidiform moles, 163 cases of complete hydatidiform moles and 14 cases of gestational trophoblastic neoplasia. During follow-up, 35 gestational trophoblastic neoplasms were diagnosed after hCG persistence. After pathology review, the overall agreement rates between our centre and a participating provider hospital was 82%. Methotrexate was the first line of single-agent chemotherapy for most patients, with resistance rates of 23%. Multi-agent chemotherapy was used as first-line treatment for five patients. None of the patients followed up by the centre died from gestational trophoblastic disease., Conclusions: This study reflects the activity of the Swiss trophoblastic disease centre from the French-speaking part of Switzerland created in 2009, and its role as local and national reference centre, in terms of global health, for women with gestational trophoblastic disease.

Disorders/differences of sex development (DSD) cause profound psychological and reproductive consequences for the affected individuals, however, most are still unexplained at the molecular level. Here, we present a novel gene, 3-hydroxy-3-methylglutaryl coenzyme A synthase 2 (HMGCS2), encoding a metabolic enzyme in the liver important for energy production from fatty acids, that shows an unusual expression pattern in developing fetal mouse gonads. Shortly after gonadal sex determination it is up-regulated in the developing testes following a very similar spatial and temporal pattern as the male-determining gene Sry in Sertoli cells before switching to ovarian enriched expression. To test if Hmgcs2 is important for gonad development in mammals, we pursued two lines of investigations. Firstly, we generated Hmgcs2-null mice using CRISPR/Cas9 and found that these mice had gonads that developed normally even on a sensitized background. Secondly, we screened 46,XY DSD patients with gonadal dysgenesis and identified two unrelated patients with a deletion and a deleterious missense variant in HMGCS2 respectively. However, both variants were heterozygous, suggesting that HMGCS2 might not be the causative gene. Analysis of a larger number of patients in the future might shed more light into the possible association of HMGCS2 with human gonadal development., Competing Interests: The authors have declared that no competing interests exist.

Trisomy 21 (T21), Down Syndrome (DS) is the most common genetic cause of dementia and intellectual disability. Modeling DS is beginning to yield pharmaceutical therapeutic interventions for amelioration of intellectual disability, which are currently being tested in clinical trials. DS is also a unique genetic system for investigation of pathological and protective mechanisms for accelerated ageing, neurodegeneration, dementia, cancer, and other important common diseases. New drugs could be identified and disease mechanisms better understood by establishment of well-controlled cell model systems. We have developed a first nonintegration-reprogrammed isogenic human induced pluripotent stem cell (iPSC) model of DS by reprogramming the skin fibroblasts from an adult individual with constitutional mosaicism for DS and separately cloning multiple isogenic T21 and euploid (D21) iPSC lines. Our model shows a very low number of reprogramming rearrangements as assessed by a high-resolution whole genome CGH-array hybridization, and it reproduces several cellular pathologies seen in primary human DS cells, as assessed by automated high-content microscopic analysis. Early differentiation shows an imbalance of the lineage-specific stem/progenitor cell compartments: T21 causes slower proliferation of neural and faster expansion of hematopoietic lineage. T21 iPSC-derived neurons show increased production of amyloid peptide-containing material, a decrease in mitochondrial membrane potential, and an increased number and abnormal appearance of mitochondria. Finally, T21-derived neurons show significantly higher number of DNA double-strand breaks than isogenic D21 controls. Our fully isogenic system therefore opens possibilities for modeling mechanisms of developmental, accelerated ageing, and neurodegenerative pathologies caused by T21., (© 2015 AlphaMed Press.)