NONO Detects the Nuclear HIV Capsid to Promote cGAS-Mediated Innate Immune Activation.

Detection of viruses by innate immune sensors induces protective antiviral immunity. The viral DNA sensor cyclic GMP-AMP synthase (cGAS) is necessary for detection of HIV by human dendritic cells and macrophages. However, synthesis of HIV DNA during infection is not sufficient for immune activation. The capsid protein, which associates with viral DNA, has a pivotal role in enabling cGAS-mediated immune activation. We now find that NONO is an essential sensor of the HIV capsid in the nucleus. NONO protein directly binds capsid with higher affinity for weakly pathogenic HIV-2 than highly pathogenic HIV-1. Upon infection, NONO is essential for cGAS activation by HIV and cGAS association with HIV DNA in the nucleus. NONO recognizes a conserved region in HIV capsid with limited tolerance for escape mutations. Detection of nuclear viral capsid by NONO to promote DNA sensing by cGAS reveals an innate strategy to achieve distinction of viruses from self in the nucleus.

Identification of a DNA methylation episignature for recurrent constellations of embryonic malformations.

The term "recurrent constellations of embryonic malformations" (RCEM) is used to describe a number of multiple malformation associations that affect three or more body structures. The causes of these disorders are currently unknown, and no diagnostic marker has been identified. Consequently, providing a definitive diagnosis in suspected individuals is challenging. In this study, genome-wide DNA methylation analysis was conducted on DNA samples obtained from the peripheral blood of 53 individuals with RCEM characterized by clinical features recognized as VACTERL and/or oculoauriculovertebral spectrum association. We identified a common DNA methylation episignature in 40 out of the 53 individuals. Subsequently, a sensitive and specific binary classifier was developed based on the DNA methylation episignature. This classifier can facilitate the use of RCEM episignature as a diagnostic biomarker in a clinical setting. The study also investigated the functional correlation of RCEM DNA methylation relative to other genetic disorders with known episignatures, highlighting the common genomic regulatory pathways involved in the pathophysiology of RCEM.

Bi-allelic loss-of-function variants in WBP4, encoding a spliceosome protein, result in a variable neurodevelopmental syndrome.

Over two dozen spliceosome proteins are involved in human diseases, also referred to as spliceosomopathies. WW domain-binding protein 4 (WBP4) is part of the early spliceosomal complex and has not been previously associated with human pathologies in the Online Mendelian Inheritance in Man (OMIM) database. Through GeneMatcher, we identified ten individuals from eight families with a severe neurodevelopmental syndrome featuring variable manifestations. Clinical manifestations included hypotonia, global developmental delay, severe intellectual disability, brain abnormalities, musculoskeletal, and gastrointestinal abnormalities. Genetic analysis revealed five different homozygous loss-of-function variants in WBP4. Immunoblotting on fibroblasts from two affected individuals with different genetic variants demonstrated a complete loss of protein, and RNA sequencing analysis uncovered shared abnormal splicing patterns, including in genes associated with abnormalities of the nervous system, potentially underlying the phenotypes of the probands. We conclude that bi-allelic variants in WBP4 cause a developmental disorder with variable presentations, adding to the growing list of human spliceosomopathies.

Author Correction: Targeted therapy in patients with PIK3CA-related overgrowth syndrome.

The 'Competing interests' statement of this Article has been updated; see accompanying Amendment for further details.

Suleiman-El-Hattab syndrome: a histone modification disorder caused by TASP1 deficiency.

BACKGROUND: TASP1 encodes an endopeptidase activating histone methyltransferases of the KMT2 family. Homozygous loss-of-function variants in TASP1 have recently been associated with Suleiman-El-Hattab syndrome. We report six individuals with Suleiman-El-Hattab syndrome and provide functional characterization of this novel histone modification disorder in a multi-omics approach. METHODS: Chromosomal microarray/exome sequencing in all individuals. Western blotting from fibroblasts in two individuals. RNA sequencing and proteomics from fibroblasts in one individual. Methylome analysis from blood in two individuals. Knock-out of tasp1 orthologue in zebrafish and phenotyping. RESULTS: All individuals had biallelic TASP1 loss-of-function variants and a phenotype including developmental delay, multiple congenital anomalies (including cardiovascular and posterior fossa malformations), a distinct facial appearance and happy demeanor. Western blot revealed absence of TASP1. RNA sequencing/proteomics showed HOX gene downregulation (HOXA4, HOXA7, HOXA1 and HOXB2) and dysregulation of transcription factor TFIIA. A distinct methylation profile intermediate between control and Kabuki syndrome (KMT2D) profiles could be produced. Zebrafish tasp1 knock-out revealed smaller head size and abnormal cranial cartilage formation in tasp1 crispants. CONCLUSION: This work further delineates Suleiman-El-Hattab syndrome, a recognizable neurodevelopmental syndrome. Possible downstream mechanisms of TASP1 deficiency include perturbed HOX gene expression and dysregulated TFIIA complex. Methylation pattern suggests that Suleiman-El-Hattab syndrome can be categorized into the group of histone modification disorders including Wiedemann-Steiner and Kabuki syndrome.

Differential alternative splicing analysis links variation in ZRSR2 to a novel type of oral-facial-digital syndrome.

PURPOSE: Oral-facial-digital (OFD) syndromes are genetically heterogeneous developmental disorders, caused by pathogenic variants in genes involved in primary cilia formation and function. We identified a previously undescribed type of OFD with brain anomalies, ranging from alobar holoprosencephaly to pituitary anomalies, in 6 unrelated families. METHODS: Exome sequencing of affected probands was supplemented with alternative splicing analysis in patient and control lymphoblastoid and fibroblast cell lines, and primary cilia structure analysis in patient fibroblasts. RESULTS: In 1 family with 2 affected males, we identified a germline variant in the last exon of ZRSR2, NM_005089.4:c.1211_1212del NP_005080.1:p.(Gly404GlufsTer23), whereas 7 affected males from 5 unrelated families were hemizygous for the ZRSR2 variant NM_005089.4:c.1207_1208del NP_005080.1:p.(Arg403GlyfsTer24), either occurring de novo or inherited in an X-linked recessive pattern. ZRSR2, located on chromosome Xp22.2, encodes a splicing factor of the minor spliceosome complex, which recognizes minor introns, representing 0.35% of human introns. Patient samples showed significant enrichment of minor intron retention. Among differentially spliced targets are ciliopathy-related genes, such as TMEM107 and CIBAR1. Primary fibroblasts containing the NM_005089.4:c.1207_1208del ZRSR2 variant had abnormally elongated cilia, confirming an association between defective U12-type intron splicing, OFD and abnormal primary cilia formation. CONCLUSION: We introduce a novel type of OFD associated with elongated cilia and differential splicing of minor intron-containing genes due to germline variation in ZRSR2.

Clinico-biological refinement of BCL11B-related disorder and identification of an episignature: A series of 20 unreported individuals.

PURPOSE: BCL11B-related disorder (BCL11B-RD) arises from rare genetic variants within the BCL11B gene, resulting in a distinctive clinical spectrum encompassing syndromic neurodevelopmental disorder, with or without intellectual disability, associated with facial features and impaired immune function. This study presents an in-depth clinico-biological analysis of 20 newly reported individuals with BCL11B-RD, coupled with a characterization of genome-wide DNA methylation patterns of this genetic condition. METHODS: Through an international collaboration, clinical and molecular data from 20 individuals were systematically gathered, and a comparative analysis was conducted between this series and existing literature. We further scrutinized peripheral blood DNA methylation profile of individuals with BCL11B-RD, contrasting them with healthy controls and other neurodevelopmental disorders marked by established episignature. RESULTS: Our findings unveil rarely documented clinical manifestations, notably including Rubinstein-Taybi-like facial features, craniosynostosis, and autoimmune disorders, all manifesting within the realm of BCL11B-RD. We refine the intricacies of T cell compartment alterations of BCL11B-RD, revealing decreased levels naive CD4+ T cells and recent thymic emigrants while concurrently observing an elevated proportion of effector-memory expressing CD45RA CD8+ T cells (TEMRA). Finally, a distinct DNA methylation episignature exclusive to BCL11B-RD is unveiled. CONCLUSION: This study serves to enrich our comprehension of the clinico-biological landscape of BCL11B-RD, potentially furnishing a more precise framework for diagnosis and follow-up of individuals carrying pathogenic BCL11B variant. Moreover, the identification of a unique DNA methylation episignature offers a valuable diagnosis tool for BCL11B-RD, thereby facilitating routine clinical practice by empowering physicians to reevaluate variants of uncertain significance within the BCL11B gene.

3q29 duplications: A cohort of 46 patients and a literature review.

Duplications of the 3q29 cytoband are rare chromosomal copy number variations (CNVs) (overlapping or recurrent ~1.6 Mb 3q29 duplications). They have been associated with highly variable neurodevelopmental disorders (NDDs) with various associated features or reported as a susceptibility factor to the development of learning disabilities and neuropsychiatric disorders. The smallest region of overlap and the phenotype of 3q29 duplications remain uncertain. We here report a French cohort of 31 families with a 3q29 duplication identified by chromosomal microarray analysis (CMA), including 14 recurrent 1.6 Mb duplications, eight overlapping duplications (>1 Mb), and nine small duplications (<1 Mb). Additional genetic findings that may be involved in the phenotype were identified in 11 patients. Focusing on apparently isolated 3q29 duplications, patients present mainly mild NDD as suggested by a high rate of learning disabilities in contrast to a low proportion of patients with intellectual disabilities. Although some are de novo, most of the 3q29 duplications are inherited from a parent with a similar mild phenotype. Besides, the study of small 3q29 duplications does not provide evidence for any critical region. Our data suggest that the overlapping and recurrent 3q29 duplications seem to lead to mild NDD and that a severe or syndromic clinical presentation should warrant further genetic analyses.

Targeted therapy in patients with PIK3CA-related overgrowth syndrome.

CLOVES syndrome (congenital lipomatous overgrowth, vascular malformations, epidermal naevi, scoliosis/skeletal and spinal syndrome) is a genetic disorder that results from somatic, mosaic gain-of-function mutations of the PIK3CA gene, and belongs to the spectrum of PIK3CA-related overgrowth syndromes (PROS). This rare condition has no specific treatment and a poor survival rate. Here, we describe a postnatal mouse model of PROS/CLOVES that partially recapitulates the human disease, and demonstrate the efficacy of BYL719, an inhibitor of PIK3CA, in preventing and improving organ dysfunction. On the basis of these results, we used BYL719 to treat nineteen patients with PROS. The drug improved the disease symptoms in all patients. Previously intractable vascular tumours became smaller, congestive heart failure was improved, hemihypertrophy was reduced, and scoliosis was attenuated. The treatment was not associated with any substantial side effects. In conclusion, this study provides the first direct evidence supporting PIK3CA inhibition as a promising therapeutic strategy in patients with PROS.

Artificial intelligence-based diagnosis in fetal pathology using external ear shapes.

OBJECTIVE: Here we trained an automatic phenotype assessment tool to recognize syndromic ears in two syndromes in fetuses-=CHARGE and Mandibulo-Facial Dysostosis Guion Almeida type (MFDGA)-versus controls. METHOD: We trained an automatic model on all profile pictures of children diagnosed with genetically confirmed MFDGA and CHARGE syndromes, and a cohort of control patients, collected from 1981 to 2023 in Necker Hospital (Paris) with a visible external ear. The model consisted in extracting landmarks from photographs of external ears, in applying geometric morphometry methods, and in a classification step using machine learning. The approach was then tested on photographs of two groups of fetuses: controls and fetuses with CHARGE and MFDGA syndromes. RESULTS: The training set contained a total of 1489 ear photographs from 526 children. The validation set contained a total of 51 ear photographs from 51 fetuses. The overall accuracy was 72.6% (58.3%-84.1%, p < 0.001), and 76.4%, 74.9%, and 86.2% respectively for CHARGE, control and MFDGA fetuses. The area under the curves were 86.8%, 87.5%, and 90.3% respectively for CHARGE, controls, and MFDGA fetuses. CONCLUSION: We report the first automatic fetal ear phenotyping model, with satisfactory classification performances. Further validations are required before using this approach as a diagnostic tool.

Prenatal exome sequencing, a powerful tool for improving the description of prenatal features associated with genetic disorders.

OBJECTIVE: Prenatal exome sequencing (pES) is now commonly used in clinical practice. It can be used to identifiy an additional diagnosis in around 30% of fetuses with structural defects and normal chromosomal microarray analysis (CMA). However, interpretation remains challenging due to the limited prenatal data for genetic disorders. METHOD: We conducted an ancillary study including fetuses with pathogenic/likely pathogenic variants identified by trio-pES from the "AnDDI-Prenatome" study. The prenatal phenotype of each patient was categorized as typical, uncommon, or unreported based on the comparison of the prenatal findings with documented findings in the literature and public phenotype-genotype databases (ClinVar, HGMD, OMIM, and Decipher). RESULTS: Prenatal phenotypes were typical for 38/56 fetuses (67.9%). For the others, genotype-phenotype associations were challenging due to uncommon prenatal features (absence of recurrent hallmark, rare, or unreported). We report the first prenatal features associated with LINS1 and PGM1 variants. In addition, a double diagnosis was identified in three fetuses. CONCLUSION: Standardizing the description of prenatal features, implementing longitudinal prenatal follow-up, and large-scale collection of prenatal features are essential steps to improving pES data interpretation.

Biallelic truncating variants in VGLL2 cause syngnathia in humans.

BACKGROUND: Syngnathia is an ultrarare craniofacial malformation characterised by an inability to open the mouth due to congenital fusion of the upper and lower jaws. The genetic causes of isolated bony syngnathia are unknown. METHODS: We used whole exome and Sanger sequencing and microsatellite analysis in six patients (from four families) presenting with syngnathia. We used CRISPR/Cas9 genome editing to generate vgll2a and vgll4l germline mutant zebrafish, and performed craniofacial cartilage analysis in homozygous mutants. RESULTS: We identified homozygous truncating variants in vestigial-like family member 2 (VGLL2) in all six patients. Two alleles were identified: one in families of Turkish origin and the other in families of Moroccan origin, suggesting a founder effect for each. A shared haplotype was confirmed for the Turkish patients. The VGLL family of genes encode cofactors of TEAD transcriptional regulators. Vgll2 is regionally expressed in the pharyngeal arches of model vertebrate embryos, and morpholino-based knockdown of vgll2a in zebrafish has been reported to cause defects in development of pharyngeal arch cartilages. However, we did not observe craniofacial anomalies in vgll2a or vgll4l homozygous mutant zebrafish nor in fish with double knockout of vgll2a and vgll4l. In Vgll2 -/- mice, which are known to present a skeletal muscle phenotype, we did not identify defects of the craniofacial skeleton. CONCLUSION: Our results suggest that although loss of VGLL2 leads to a striking jaw phenotype in humans, other vertebrates may have the capacity to compensate for its absence during craniofacial development.

Size matters: Large copy number losses in Hirschsprung disease patients reveal genes involved in enteric nervous system development.

Hirschsprung disease (HSCR) is a complex genetic disease characterized by absence of ganglia in the intestine. HSCR etiology can be explained by a unique combination of genetic alterations: rare coding variants, predisposing haplotypes and Copy Number Variation (CNV). Approximately 18% of patients have additional anatomical malformations or neurological symptoms (HSCR-AAM). Pinpointing the responsible culprits within a CNV is challenging as often many genes are affected. Therefore, we selected candidate genes based on gene enrichment strategies using mouse enteric nervous system transcriptomes and constraint metrics. Next, we used a zebrafish model to investigate whether loss of these genes affects enteric neuron development in vivo. This study included three groups of patients, two groups without coding variants in disease associated genes: HSCR-AAM and HSCR patients without associated anomalies (HSCR-isolated). The third group consisted of all HSCR patients in which a confirmed pathogenic rare coding variant was identified. We compared these patient groups to unaffected controls. Predisposing haplotypes were determined, confirming that every HSCR subgroup had increased contributions of predisposing haplotypes, but their contribution was highest in isolated HSCR patients without RET coding variants. CNV profiling proved that specifically HSCR-AAM patients had larger Copy Number (CN) losses. Gene enrichment strategies using mouse enteric nervous system transcriptomes and constraint metrics were used to determine plausible candidate genes located within CN losses. Validation in zebrafish using CRISPR/Cas9 targeting confirmed the contribution of UFD1L, TBX2, SLC8A1, and MAPK8 to ENS development. In addition, we revealed epistasis between reduced Ret and Gnl1 expression and between reduced Ret and Tubb5 expression in vivo. Rare large CN losses-often de novo-contribute to HSCR in HSCR-AAM patients. We proved the involvement of six genes in enteric nervous system development and Hirschsprung disease.

Bi-allelic Variations of SMO in Humans Cause a Broad Spectrum of Developmental Anomalies Due to Abnormal Hedgehog Signaling.

The evolutionarily conserved hedgehog (Hh) pathway is essential for organogenesis and plays critical roles in postnatal tissue maintenance and renewal. A unique feature of the vertebrate Hh pathway is that signal transduction requires the primary cilium (PC) where major pathway components are dynamically enriched. These factors include smoothened (SMO) and patched, which constitute the core reception system for sonic hedgehog (SHH) as well as GLI transcription factors, the key mediators of the pathway. Here, we report bi-allelic loss-of-function variations in SMO in seven individuals from five independent families; these variations cause a wide phenotypic spectrum of developmental anomalies affecting the brain (hypothalamic hamartoma and microcephaly), heart (atrioventricular septal defect), skeleton (postaxial polydactyly, narrow chest, and shortening of long bones), and enteric nervous system (aganglionosis). Cells derived from affected individuals showed normal ciliogenesis but severely altered Hh-signal transduction as a result of either altered PC trafficking or abnormal activation of the pathway downstream of SMO. In addition, Hh-independent GLI2 accumulation at the PC tip in cells from the affected individuals suggests a potential function of SMO in regulating basal ciliary trafficking of GLI2 when the pathway is off. Thus, loss of SMO function results in abnormal PC dynamics of key components of the Hh signaling pathway and leads to a large continuum of malformations in humans.

Pediatric Tumors and Developmental Anomalies: A French Nationwide Cohort Study.

OBJECTIVE: To assess the associations between congenital abnormalities and pediatric malignancies and evaluate the potential underlying molecular basis by collecting information on pediatric patients with cancer and congenital abnormalities. STUDY DESIGN: Tumeur Et Développement is a national, prospective, and retrospective multicenter study recording data of children with cancer and congenital abnormalities. When feasible, blood and tumoral samples are collected for virtual biobanking. RESULTS: From June 2013 to December 2019, 679 associations between pediatric cancers and congenital abnormalities were recorded. The most represented cancers were central nervous system tumors (n = 139; 20%), leukemia and myelodysplastic syndromes (n = 123; 18.1%), and renal tumors (n = 101; 15%). Congenital abnormalities were not related to any known genetic disorder in 66.5% of cases. In this group, the most common anomaly was intellectual disability (22.3%), followed by musculoskeletal (14.2%) and genitourinary anomalies (12.4%). Intellectual disability was mostly associated with hematologic malignancies. Embryonic tumors (neuroblastoma, Wilms tumor, and rhabdomyosarcoma) were associated with consistent abnormalities, sometimes with a close anatomical neighborhood between the abnormality and the neoplasm. CONCLUSIONS: In the first Tumeur Et Développement analysis, 3 major themes have been identified: (1) germline mutations with or without known cancer predisposition, (2) postzygotic events responsible for genomic mosaicism, (3) coincidental associations. New pathways involved in cancer development need to be investigated to improve our understanding of childhood cancers.

Low risk of embryonic and other cancers in PIK3CA-related overgrowth spectrum: Impact on screening recommendations.

The PIK3CA-related overgrowth spectrum (PROS) encompasses various conditions caused by mosaic activating PIK3CA variants. PIK3CA somatic variants are also involved in various cancer types. Some generalized overgrowth syndromes are associated with an increased risk of Wilms tumor (WT). In PROS, abdominal ultrasound surveillance has been advocated to detect WT. We aimed to determine the risk of embryonic and other types of tumors in patients with PROS in order to evaluate surveillance relevance. We searched the clinical charts from 267 PROS patients for the diagnosis of cancer, and reviewed the medical literature for the risk of cancer. In our cohort, six patients developed a cancer (2.2%), and Kaplan Meier analyses estimated cumulative probabilities of cancer occurrence at 45 years of age was 5.6% (95% CI = 1.35%-21.8%). The presence of the PIK3CA variant was only confirmed in two out of four tumor samples. In the literature and our cohort, six cases of Wilms tumor/nephrogenic rests (0.12%) and four cases of other cancers have been reported out of 483 proven PIK3CA patients, in particular the p.(His1047Leu/Arg) variant. The risk of WT in PROS being lower than 5%, this is insufficient evidence to recommend routine abdominal imaging. Long-term follow-up studies are needed to evaluate the risk of other cancer types, as well as the relationship with the extent of tissue mosaicism and the presence or not of the variant in the tumor samples.

An automatic facial landmarking for children with rare diseases.

Two to three thousand syndromes modify facial features: their screening requires the eye of an expert in dysmorphology. A widely used tool in shape characterization is geometric morphometrics based on landmarks, which are precise and reproducible anatomical points. Landmark positioning is user dependent and time consuming. Many automatic landmarking tools are currently available but do not work for children, because they have mainly been trained using photographic databases of healthy adults. Here, we developed a method for building an automatic landmarking pipeline for frontal and lateral facial photographs as well as photographs of external ears. We evaluated the algorithm on patients diagnosed with Treacher Collins (TC) syndrome as it is the most frequent mandibulofacial dysostosis in humans and is clinically recognizable although highly variable in severity. We extracted photographs from the photographic database of the maxillofacial surgery and plastic surgery department of Hôpital Necker-Enfants Malades in Paris, France with the diagnosis of TC syndrome. The control group was built from children admitted for craniofacial trauma or skin lesions. After testing two methods of object detection by bounding boxes, a Haar Cascade-based tool and a Faster Region-based Convolutional Neural Network (Faster R-CNN)-based tool, we evaluated three different automatic annotation algorithms: the patch-based active appearance model (AAM), the holistic AAM, and the constrained local model (CLM). The final error corresponding to the distance between the points placed by automatic annotation and those placed by manual annotation was reported. We included, respectively, 1664, 2044, and 1375 manually annotated frontal, profile, and ear photographs. Object recognition was optimized with the Faster R-CNN-based detector. The best annotation model was the patch-based AAM (p < 0.001 for frontal faces, p = 0.082 for profile faces and p < 0.001 for ears). This automatic annotation model resulted in the same classification performance as manually annotated data. Pretraining on public photographs did not improve the performance of the model. We defined a pipeline to create automatic annotation models adapted to faces with congenital anomalies, an essential prerequisite for research in dysmorphology.

Retrospective evaluation of clinical and molecular data of 148 cases of esophageal atresia.

Developmental abnormalities provide a unique opportunity to seek for the molecular mechanisms underlying human organogenesis. Esophageal development remains incompletely understood and elucidating causes for esophageal atresia (EA) in humans would contribute to achieve a better comprehension. Prenatal detection, syndromic classification, molecular diagnosis, and prognostic factors in EA are challenging. Some syndromes have been described to frequently include EA, such as CHARGE, EFTUD2-mandibulofacial dysostosis, Feingold syndrome, trisomy 18, and Fanconi anemia. However, no molecular diagnosis is made in most cases, including frequent associations, such as Vertebral-Anal-Cardiac-Tracheo-Esophageal-Renal-Limb defects (VACTERL). This study evaluates the clinical and genetic test results of 139 neonates and 9 fetuses followed-up at the Necker-Enfants Malades Hospital over a 10-years period. Overall, 52 cases were isolated EA (35%), and 96 were associated with other anomalies (65%). The latter group is divided into three subgroups: EA with a known genomic cause (9/148, 6%); EA with Vertebral-Anal-Cardiac-Tracheo-Esophageal-Renal-Limb defects (VACTERL) or VACTERL/Oculo-Auriculo-Vertebral Dysplasia (VACTERL/OAV) (22/148, 14%); EA with associated malformations including congenital heart defects, duodenal atresia, and diaphragmatic hernia without known associations or syndromes yet described (65/148, 44%). Altogether, the molecular diagnostic rate remains very low and may underlie frequent non-Mendelian genetic models.

Phenotypic spectrum and genomics of undiagnosed arthrogryposis multiplex congenita.

BACKGROUND: Arthrogryposis multiplex congenita (AMC) is characterised by congenital joint contractures in two or more body areas. AMC exhibits wide phenotypic and genetic heterogeneity. Our goals were to improve the genetic diagnosis rates of AMC, to evaluate the added value of whole exome sequencing (WES) compared with targeted exome sequencing (TES) and to identify new genes in 315 unrelated undiagnosed AMC families. METHODS: Several genomic approaches were used including genetic mapping of disease loci in multiplex or consanguineous families, TES then WES. Sanger sequencing was performed to identify or validate variants. RESULTS: We achieved disease gene identification in 52.7% of AMC index patients including nine recently identified genes (CNTNAP1, MAGEL2, ADGRG6, ADCY6, GLDN, LGI4, LMOD3, UNC50 and SCN1A). Moreover, we identified pathogenic variants in ASXL3 and STAC3 expanding the phenotypes associated with these genes. The most frequent cause of AMC was a primary involvement of skeletal muscle (40%) followed by brain (22%). The most frequent mode of inheritance is autosomal recessive (66.3% of patients). In sporadic patients born to non-consanguineous parents (n=60), de novo dominant autosomal or X linked variants were observed in 30 of them (50%). CONCLUSION: New genes recently identified in AMC represent 21% of causing genes in our cohort. A high proportion of de novo variants were observed indicating that this mechanism plays a prominent part in this developmental disease. Our data showed the added value of WES when compared with TES due to the larger clinical spectrum of some disease genes than initially described and the identification of novel genes.

Developmental outcome of children with Robin sequence treated with the current Paris protocol.

AIM: We aimed to investigate the developmental outcome of children with Robin sequence (RS) for whom continuous positive airway pressure was the main strategy to release upper airway obstruction. METHODS: We included children with isolated RS or RS associated with Stickler syndrome who were aged 15 months to 6 years. We used the French version of the Child Development Inventory and calculated the developmental quotient (DQ) for eight different domains and the global DQ (DQ-global). We searched for determinants of risk of delay. RESULTS: Of the 87 children, for 71%, the developmental evolution was within the norm (DQ-global ≥86 or ≥-1 SD), 29% were at high risk of delay (DQ-global <86 or <-1 SD), and only 3% were at very high risk of delay (DQ-global <70 or <-2 SD). The DQs for expressive language and language comprehension were lower in our study population than the general population, but an improvement was noticed with the children's growth. CONCLUSION: Risk of a developmental delay was not greater for children with the most severe respiratory phenotype than the others. Children whose mothers had low education levels were more at risk than the others.