Explore the vast range of titles available.

The prognostic value of IL7-receptor pathway (IL7Rp) mutations in T-cell acute lymphoblastic leukemia (T-ALL) remains unclear. We performed a comprehensive study of 200 adult patients with T-ALL included in the GRAALL2003/2005 protocols to address the clinical significance of IL7Rp mutations. Next-generation sequencing of the IL7Rp (IL7R/JAK1/JAK3/STAT5B) revealed that IL7Rp mutations were frequent in adult T-ALL (28%) particularly in immature/early T-cell progenitor (ETP)-ALL. They were associated with mutations of NOTCH-pathway, PHF6, and PRC2 components but not with K/NRAS. IL7Rp mutated (IL7Rpmut) T-ALL were slow-responders, with a high rate of M2/M3 day-8 marrow compared with IL7Rp non-mutated (IL7RpWT) T-ALL (p = 0.002) and minimal residual disease positivity at 6-weeks (MRD1) (p = 0.008) but no difference in MRD2 positivity at 12-weeks. Despite this, no adverse prognosis was evidenced when censored for allogeneic hematopoietic stem cell transplantation (HSCT). In time-dependent analysis, HSCT did not benefit IL7Rpmut patients whereas it was of marked benefit to IL7RpWT cases. IL7Rp-mutations identify a subgroup of slow-responder T-ALLs which benefit from post-induction chemotherapy regimens but not from HSCT. Our data suggest that prior knowledge of the mutation status of IL7Rp may influence HSCT decision and help to guide therapy reduction.

Objective Genetic testing is now included in the diagnostic assessment of childhood onset epilepsies. We evaluated the yield of a targeted next generation sequencing (TNGS) panel dedicated to pediatric epilepsies. Methods We tested by TNGS panel 1000 consecutive patients presenting with childhood onset epilepsies and including mainly patients with early onset epilepsies (under 2 years, 61%). Results Causal variants were identified in 31% of patients, spanning 78 different genes. Patients with benign familial neonatal/infantile epilepsy (BFN/IS) exhibited the highest rate of positive findings (82%). Developmental and epileptic encephalopathies (DEEs) had a global diagnostic yield of 37%, with epilepsy of infancy with migrating focal seizures (EIMFSI) and Dravet syndrome (DS) presenting the highest yield in this group (78%) and early infantile DEE (EIDEE) laying next with a yield of 43%. The lowest rates of genetic diagnosis were observed in infantile epileptic spasms syndrome (IESS, 17%), epilepsy with myoclonic‐atonic seizures (EMAtS, 19%), and DEE‐SWAS (14%). Patients with GEFS+ had a yield of 16%. Among patients with developmental encephalopathies and refractory seizures with onset after 2 years, TNGS yielded a 33% diagnostic rate. Atypical absences yielded 16%, focal epilepsy yielded 18%, and generalized epilepsies with refractory seizures yielded 13%. These groups exhibited a high genetic heterogeneity. Significance TNGS is an effective first‐step genetic screening in patients with high diagnostic yields (BFN/IS, EIMFS, DS, EIDEE) and for epilepsy syndromes associated with one or a few major genes (BFN/IS, EIMFS, DS, GEFS+, DEE‐SWAS). Whole exome or genome sequencing (WES/WGS) should be considered as a second step in these groups with a probably relevant Mendelian inheritance. WES/WGS could be proposed as first‐tier analysis in patients with IESS, EMAtS, generalized or focal epilepsies refractory to ASMs, and developmental encephalopathies with seizure onset after 2 years. However, the lower diagnostic yield obtained in these groups may suggest a complex inheritance. Plain Language Summary This study emphasizes the importance of accurately identifying different types of epilepsy and epilepsy syndromes to improve genetic testing strategies. We suggest that a targeted gene panel can be a good first step for some genetic conditions, such as benign familial neonatal/infantile epilepsy, Dravet syndrome, and epilepsy of infancy with migrating focal seizures.

CREBBP truncating mutations and deletions are responsible for the well-known Rubinstein-Taybi syndrome. Recently, a new, distinct CREBBP-linked syndrome has been described: missense mutations located at the 3' end of exon 30 and the 5' portion of exon 31 induce Menke-Hennekam syndrome. Patients with this syndrome present a recognizable facial dysmorphism, intellectual disability of variable severity, microcephaly, short stature, autism, epilepsy, visual and hearing impairments, feeding problems, upper airway infections, scoliosis, and/or kyphosis. To date, all diagnoses were made postnatally. Trio-whole exome sequencing (WES) was performed in a fetus showing increased nuchal translucency persistence and aorta abnormalities at 28 weeks of gestation (WG). WES revealed a CREBBP de novo missense mutation (c.5602C>T; p.Arg1868Trp) in exon 31, previously reported as the cause of Menke-Hennekam syndrome. Termination of pregnancy was performed at 32 WG. We further reviewed the prenatal signs of Menke-Hennekam syndrome already reported. Among the 35 patients reported and diagnosed postnatally up to this day, 15 presented recognizable prenatal signs, the most frequent being intra-uterine growth retardation, brain, and cardiovascular anomalies. Menke-Hennekam is a rare syndrome with unspecific, heterogeneous, and inconstant prenatal symptoms occurring most frequently with the c.5602C>T, p.(Arg1868Trp) mutation. Therefore, the prenatal diagnosis of Menke-Hennekam syndrome is only possible by molecular investigation. Moreover, this case report and review reinforce the importance of performing prenatal WES when unspecific signs are present on imaging.

Background CDG2L (MIM#614576) is an autosomal recessive multisystemic disorder due to variants in COG6 gene. Postnatal phenotypes are now well described, while prenatal presentations remain poorly investigated. Only 8 of the 28 published patients have had prenatal ultrasound anomalies reported and no one post‐mortem investigation. Methods We used whole‐exome sequencing in a consanguineous Turkish family with four siblings presenting with Pierre Robin sequence, arthrogryposis, heart malformation, splenomegaly, hydrocephaly, corpus callosum dysgenesis, brainstem, and cerebellar hypoplasia. Results We identified a novel homozygous pathogenic variant in exon 9 of COG6 (NM_020751.2): c.821del, p.(Arg274Lysfs*32). In this family, our post‐mortem study led us to describe further the prenatal phenotype of CDG2L. In addition, it permits correlating the most relevant anomalies to a maldevelopmental cascade due to a neurodegenerative process of metabolic origin, affecting the entire central nervous system including the spinal cord. Conclusion In this context of recurrence of multisystemic disease diagnosed antenatally, exome sequencing is powerful to give a precise diagnosis and allows proposing a molecular prenatal diagnosis at the following pregnancy.

Poc1 (Protein of Centriole 1) proteins are highly conserved WD40 domain-containing centriole components, well characterized in the alga Chlamydomonas, the ciliated protazoan Tetrahymena, the insect Drosophila and in vertebrate cells including Xenopus and zebrafish embryos. Functions and localizations related to the centriole and ciliary axoneme have been demonstrated for Poc1 in a range of species. The vertebrate Poc1 protein has also been reported to show an additional association with mitochondria, including enrichment in the specialized \"germ plasm\" region of Xenopus oocytes. We have identified and characterized a highly conserved Poc1 protein in the cnidarian Clytia hemisphaerica. Clytia Poc1 mRNA was found to be strongly expressed in eggs and early embryos, showing a punctate perinuclear localization in young oocytes. Fluorescence-tagged Poc1 proteins expressed in developing embryos showed strong localization to centrioles, including basal bodies. Anti-human Poc1 antibodies decorated mitochondria in Clytia, as reported in human cells, but failed to recognise endogenous or fluorescent-tagged Clytia Poc1. Injection of specific morpholino oligonucleotides into Clytia eggs prior to fertilization to repress Poc1 mRNA translation interfered with cell division from the blastula stage, likely corresponding to when neosynthesis normally takes over from maternally supplied protein. Cell cycle lengthening and arrest were observed, phenotypes consistent with an impaired centriolar biogenesis or function. The specificity of the defects could be demonstrated by injection of synthetic Poc1 mRNA, which restored normal development. We conclude that in Clytia embryos, Poc1 has an essentially centriolar localization and function.

BackgroundWhile mitochondrial DNA (mtDNA) copy number is strictly regulated during differentiation and according to cell type, very little is known regarding the mechanism which accurately controls mtDNA copy number in human. Exon 2 of the human POLG gene, encoding the catalytic subunit of the mitochondrial-specific DNA polymerase gamma, contains a CpG island, highly conserved in mice and human. Changes of DNA methylation at the POLG locus have been shown to modulate mtDNA copy number during cell differentiation in both mouse and human.MethodsWe have investigated the epigenetic modification of the POLG gene, by assessing the methylation level of its exon 2 using deep-Next Generation Sequencing analysis of bisulfite-treated DNA. Analysis were performed on various tissues at either postnatal or prenatal stages, on samples from carriers of mtDNA mutations, patients carrying two loss-of-function POLG mutations and controls.ResultsVery high methylation levels at POLG exon 2 were found (94±3%) and no variation was observed according to either developmental stage or tissue of origin, except for sperm samples for which lower methylation levels were found (80%). This high level of methylation was neither correlated with the presence of mtDNA mutations (94±1% of methylated alleles), nor with biallelic POLG mutations (93%±2%), even in tissues where a mtDNA depletion had been observed.ConclusionsThis study suggests that, at variance with mouse and un/de-differentiated human cells, differentiated human cells control mtDNA levels irrespective of POLG methylation. The factors which actually control the mtDNA levels in such cell types remain to be identified.

Leber congenital amaurosis (LCA) encompasses the earliest and most severe retinal dystrophies and can occur as a non-syndromic or a syndromic disease. Molecular diagnosis in LCA is of particular importance in clinical decision-making and patient care since it can provide ocular and extraocular prognostics and identify patients eligible to develop gene-specific therapies. Routine high-throughput molecular testing in LCA yields 70%–80% of genetic diagnosis. In this study, we aimed to investigate the non-coding regions of one non-syndromic LCA gene, RPGRIP1, in a series of six families displaying one single disease allele after a gene-panel screening of 722 LCA families which identified 26 biallelic RPGRIP1 families. Using trio-based high-throughput whole locus sequencing (WLS) for second disease alleles, we identified a founder deep intronic mutation (NM_020366.3:c.1468-128T>G) in 3/6 families. We employed Sanger sequencing to search for the pathologic variant in unresolved LCA cases (106/722) and identified three additional families (two homozygous and one compound heterozygous with the NM_020366.3:c.930+77A>G deep intronic change). This makes the c.1468-128T>G the most frequent RPGRIP1 disease allele (8/60, 13%) in our cohort. Studying patient lymphoblasts, we show that the pathologic variant creates a donor splice-site and leads to the insertion of the pseudo-exon in the mRNA, which we were able to hamper using splice-switching antisense oligonucleotides (AONs), paving the way to therapies.

Kinesins play a critical role in the organization and dynamics of the microtubule cytoskeleton, making them central players in neuronal proliferation, neuronal migration, and postmigrational development. Recently, KIF2A mutations were identified in cortical malformation syndromes associated with microcephaly. Here, we detected two de novo p.Ser317Asn and p.His321Pro mutations in KIF2A in two patients with lissencephaly and microcephaly. In parallel, we re-evaluated the two previously reported cases showing de novo mutations of the same residues. The identification of mutations only in the residues Ser317 and His321 suggests these are hotspots for de novo mutations. Both mutations lead to a classic form of lissencephaly, with a posterior to anterior gradient, almost indistinguishable from LIS1- related lissencephaly. However, three fourths of patients also showed variable congenital and postnatal microcephaly, up to −5 SD. Located in the motor domain of the KIF2A protein, the Ser317 and His321 alterations are expected to disrupt binding or hydrolysis of ATP and consequently the MT depolymerizing activity. This report also establishes that KIF2A mutations represent significant causes of classic lissencephaly with microcephaly.

Jellyfish (medusae) are a distinctive life-cycle stage of medusozoan cnidarians. They are major marine predators, with integrated neurosensory, muscular and organ systems. The genetic foundations of this complex form are largely unknown. We report the draft genome of the hydrozoan jellyfish Clytia hemisphaerica and use multiple transcriptomes to determine gene use across life-cycle stages. Medusa, planula larva and polyp are each characterised by distinct transcriptome signatures reflecting abrupt life cycle transitions, and all deploy a mixture of phylogenetically old and new genes. Medusa specific transcription factors, including many with bilaterian orthologs, associate with diverse neurosensory structures. Compared to Clytia, the polyp-only hydrozoan Hydra has lost many of the medusa-expressed transcription factors, despite similar overall rates of gene content and sequence evolution. Absence of expression and gene loss among Clytia orthologs of genes patterning the anthozoan aboral pole, secondary axis and endomesoderm support simplification of planulae and polyps in Hydrozoa, including loss of bilateral symmetry. Consequently, although the polyp and planula are generally considered the ancestral cnidarian forms, in Clytia the medusa maximally deploys ancestral cnidarian bilaterian transcription factor gene complexity.