Arthrogryposis multiplex congenita (AMC) is caused by heterogeneous pathologies leading to multiple antenatal joint contractures through fetal akinesia. Understanding the pathophysiology of this disorder is important for clinical care of the affected individuals and genetic counseling of the families. We thus aimed to establish the genetic basis of an AMC subtype that is associated with multiple dysmorphic features and intellectual disability (ID). We used haplotype analysis, next-generation sequencing, array comparative genomic hybridization, and chromosome breakpoint mapping to identify the pathogenic mutations in families and simplex cases. Suspected disease variants were verified by cosegregation analysis. We identified disease-causing mutations in the zinc-finger gene ZC4H2 in four families affected by X-linked AMC plus ID and one family affected by cerebral palsy. Several heterozygous females were also affected, but to a lesser degree. Furthermore, we found two ZC4H2 deletions and one rearrangement in two female and one male unrelated simplex cases, respectively. In mouse primary hippocampal neurons, transiently produced ZC4H2 localized to the postsynaptic compartment of excitatory synapses, and the altered protein influenced dendritic spine density. In zebrafish, antisense-morpholino-mediated zc4h2 knockdown caused abnormal swimming and impaired α-motoneuron development. All missense mutations identified herein failed to rescue the swimming defect of zebrafish morphants. We conclude that ZC4H2 point mutations, rearrangements, and small deletions cause a clinically variable broad-spectrum neurodevelopmental disorder of the central and peripheral nervous systems in both familial and simplex cases of both sexes. Our results highlight the importance of ZC4H2 for genetic testing of individuals presenting with ID plus muscle weakness and minor or major forms of AMC.

Background Severe congenital ophthalmological malformations and glaucoma might be an important occasional feature in patients with Coffin-Siris syndrome (CSS), especially Coffin-Siris syndrome 9 (CSS9, OMIM #615866) caused by SOX11 mutation. Recently, primary (open-angle) glaucoma was described in two children with the most common form of Coffin-Siris syndrome, CSS1 (OMIM #135900) by ARID1B (AT-rich interaction domain-containing protein 1B) gene mutation. In this article, we present the first report of glaucoma with Coffin-Siris syndrome 9 as well as the first report of secondary glaucoma with any form of Coffin-Siris syndrome. These findings indicate that secondary glaucoma is an occasional finding in patients with Coffin-Siris syndrome. Case presentation A child with secondary childhood glaucoma and additional ocular manifestations was evaluated and treated at the childhood glaucoma centre in Mainz, Germany. Examination under general anaesthesia revealed ocular anterior segment dysgenesis (ASD) (Peters type iridocorneal dysgenesis) in combination with congenital limbal stem cell deficiency (LSCD), aniridia, and cataract. The patient also had multiple other congenital anomalies and severe developmental delay. To explain his combination of anomalies, molecular genetic analysis from peripheral blood was performed in late 2018 and early 2019. Following normal findings with a panel diagnostic of 18 genes associated with congenital glaucoma, whole exome sequencing was performed and revealed a novel likely pathogenic heterozygous variant c.251G>T, p.(Gly84Val) in the SOX11 gene (SRY-related HMG-box gene 11). The variant had occurred de novo. Thus, the multiple congenital anomalies and developmental delay of the patient represented Coffin-Siris syndrome 9 (CSS9, OMIM #615866). Conclusions When eye diseases occur in combination with other systemic features, genetic analysis can be seminal. Results indicate that glaucoma is an occasional feature of patients with Coffin-Siris syndrome. As early treatment may improve the visual outcome of patients with glaucoma, we suggest that patients with Coffin-Siris syndrome should receive specific ophthalmological screening.

There are two forms of diabetes insipidus, central (neurohypophyseal), and nephrogenic, caused by pathogenic variants in the AVP gene and the AVPR2 or AQP2 genes, respectively. We report on a four-generation family, seven individuals had central diabetes insipidus (CDI) and the female index patient seen from age 16 to 26 years had (mild) nephrogenic diabetes insipidus. In her father with CDI, a known pathogenic heterozygous AVP variant c.232_234del p.(Glu78del) was identified, confirming the diagnosis of CDI in him and the other affected family members. In the proband, molecular analysis disclosed a novel heterozygous AVPR2 gene variant, c.962A > T p.(Asn321Ile) and an extremely skewed X-inactivation, confirming Xlinked nephrogenic diabetes insipidus (XL-NDI). Whole exome sequencing showed no further causative mutation. This is the first report on the co-existence of CDI and NDI in one family. Our review of symptomatic female AVPR2 heterozygotes includes 23 families with at least one affected female (including this study). There were 21 different causative mutations. Mutation types in females did not differ from those in males. Both severe XL-NDI and mild forms were reported in females. All six females with severe XL-NDI had complete loss-of-function (null) mutations. The remaining 17 female probands had milder XL-NDI caused by 14 missense variants and three null variants of the AVPR2 gene. X-inactivation was studied in nine of these females; all showed extreme or slight skewing. The review underlines that XL-NDI in female AVPR2 heterozygotes is always accompanied by skewed X-inactivation, emphasizing a need for X-inactivation studies in these females. K E Y W O R D S affected female, AVP, AVPR2, central (neurohypophyseal) diabetes insipidus, gender medicine, nephrogenic (renal) diabetes insipidus

The European Society of Human Genetics (ESHG) was founded in 1967 as a professional organisation for members working in genetics in clinical practice, research and education. The Society seeks the integration of scientific research and its implementation into clinical practice and the education of specialists and the public in all areas of medical and human genetics. The Society works to do this through many approaches, including educational sessions at the annual conference; training courses in general and specialist areas of genetics; an online resource of educational materials (EuroGEMS); and a mentorship scheme. The ESHG Education Committee is implementing new approaches to expand the reach of its educational activities and portfolio. With changes in technology, appreciation of the utility of genomics in healthcare and the public’s and patients’ increased awareness of the role of genomics, this review will summarise how the ESHG is adapting to deliver innovative educational activity.

Human Genetics is a rapidly expanding field at the intersection of science and medicine, which aims to understand the mechanisms involved in the functioning of the human body.The search for the molecular basis of human health and the study of traits transmitted from parents to children gave rise to the field of Medical Genetics less than half a century ago [1]. This relatively young discipline is of great importance for diagnosing and understanding human diseases, predicting a possible risk of recurrence, and developing therapeutic strategies. Human Genetics comprises a scientific field with fundamental or translational research units and a medical field including Clinical Genetics and diagnostic laboratories (cytogenetics, biochemical and molecular genetics) [2].Young geneticists (YG) face difficulties in accessing training and may feel professionally isolated due to the small number of peers at a local level. Although the use of the internet has greatly improved the cross-border dissemination of knowledge and data, human and technical resources vary considerably around the world leading to inequalities in training and practice. In addition, rapidly changing technologies have led to a widening generational gap between young and senior professionals [3]. YG strongly felt the need for an online community that could: promote human genetics to young people, connect isolated professionals, encourage ambitious collaborations, reduce inequalities and the generational gap.