0000000000043335
AUTHOR
David Geneviève
IQSEC2-related encephalopathy in males and females: a comparative study including 37 novel patients.
Variants in IQSEC2, escaping X inactivation, cause X-linked intellectual disability with frequent epilepsy in males and females. We aimed to investigate sex-specific differences.
The oculoauriculofrontonasal syndrome: Further clinical characterization and additional evidence suggesting a nontraditional mode of inheritance
IF 2.264; International audience; The oculoauriculofrontonasal syndrome (OAFNS) is a rare disorder characterized by the association of frontonasal dysplasia (widely spaced eyes, facial cleft, and nose abnormalities) and oculo-auriculo-vertebral spectrum (OAVS)-associated features, such as preauricular ear tags, ear dysplasia, mandibular asymmetry, epibulbar dermoids, eyelid coloboma, and costovertebral anomalies. The etiology is unknown so far. This work aimed to identify molecular bases for the OAFNS. Among a cohort of 130 patients with frontonasal dysplasia, accurate phenotyping identified 18 individuals with OAFNS. We describe their clinical spectrum, including the report of new features…
Excess of de novo variants in genes involved in chromatin remodelling in patients with marfanoid habitus and intellectual disability.
PurposeMarfanoid habitus (MH) combined with intellectual disability (ID) (MHID) is a clinically and genetically heterogeneous presentation. The combination of array CGH and targeted sequencing of genes responsible for Marfan or Lujan–Fryns syndrome explain no more than 20% of subjects.MethodsTo further decipher the genetic basis of MHID, we performed exome sequencing on a combination of trio-based (33 subjects) or single probands (31 subjects), of which 61 were sporadic.ResultsWe identified eight genes with de novo variants (DNVs) in at least two unrelated individuals (ARID1B, ATP1A1, DLG4, EHMT1, NFIX, NSD1, NUP205 and ZEB2). Using simulation models, we showed that five genes (DLG4, NFIX, …
Molecular, clinical and neuropsychological study in 31 patients with Kabuki syndrome and KMT2D mutations
IF 3.326; International audience; Kabuki syndrome (KS-OMIM 147920) is a rare developmental disease characterized by the association of multiple congenital anomalies and intellectual disability. This study aimed to investigate intellectual performance in children with KS and link the performance to several clinical features and molecular data. We recruited 31 children with KMT2D mutations who were 6 to 16 years old. They all completed the Weschler Intelligence Scale for Children, fourth edition. We calculated all indexes: the Full Scale Intellectual Quotient (FSIQ), Verbal Comprehension Index (VCI), Perceptive Reasoning Index (PRI), Processing Speed Index (PSI), and Working Memory Index (WMI…
De novo mutations in the X-linked TFE3 gene cause intellectual disability with pigmentary mosaicism and storage disorder-like features
IntroductionPigmentary mosaicism (PM) manifests by pigmentation anomalies along Blaschko’s lines and represents a clue toward the molecular diagnosis of syndromic intellectual disability (ID). Together with new insights on the role for lysosomal signalling in embryonic stem cell differentiation, mutations in the X-linked transcription factor 3 (TFE3) have recently been reported in five patients. Functional analysis suggested these mutations to result in ectopic nuclear gain of functions.Materials and methodsSubsequent data sharing allowed the clustering of de novo TFE3 variants identified by exome sequencing on DNA extracted from leucocytes in patients referred for syndromic ID with or with…
TBL1XR1 mutations in Pierpont syndrome are not restricted to the recurrent p.Tyr446Cys mutation
IF 2.264; International audience; Pierpont syndrome is a rare and sporadic syndrome, including developmental delay, facial characteristics, and abnormal extremities. Recently, a recurrent de novo TBL1XR1 variant (c.1337A > G; p.Tyr446Cys) has been identified in eight patients by whole‐exome sequencing. A dominant‐negative effect of this mutation is strongly suspected, since patients with TBL1XR1 deletion and other variants predicting loss of function do not share the same phenotype. We report two patients with typical Pierpont‐like syndrome features. Exome sequencing allowed identifying a de novo heterozygous missense TBL1XR1 variant in both patients, different from those already reported: …
Mutations activatrices de mTOR en mosaïque dans l’hypomélanose d’Ito avec mégalencéphalie
Introduction L’hypomelanose d’Ito (HI) est definie par une hypopigmentation suivant les lignes de Blaschko, isolee ou associee a des manifestations principalement neurologiques. Nous rapportons ici une anomalie genetique en mosaique commune chez des patients atteints d’HI avec megalencephalie. Materiel et methodes Cinq enfants (3 filles, 2 garcons), sans antecedents familiaux, ayant des troubles pigmentaires et une megalencephalie ont ete etudies. Quatre avaient une hypopigmentation blaschko-lineaire, et un avait une meche blanche avec hypochromie scapulaire en quadrant et heterochromie irienne. Tous avaient une macrocrânie precoce (PC > 3 DS) et un retard des acquisitions. La patiente prin…
NFIB Haploinsufficiency Is Associated with Intellectual Disability and Macrocephaly
The nuclear factor I (NFI) family of transcription factors play an important role in normal development of multiple organs. Three NFI family members are highly expressed in the brain, and deletions or sequence variants in two of these, NFIA and NFIX, have been associated with intellectual disability (ID) and brain malformations. NFIB, however, has not previously been implicated in human disease. Here, we present a cohort of 18 individuals with mild ID and behavioral issues who are haploinsufficient for NFIB. Ten individuals harbored overlapping microdeletions of the chromosomal 9p23-p22.2 region, ranging in size from 225 kb to 4.3 Mb. Five additional subjects had point sequence variations c…
Correction: IQSEC2-related encephalopathy in males and females:a comparative study including 37 novel patients
This Article was originally published under Nature Research’s License to Publish, but has now been made available under a CC BY 4.0 license. The PDF and HTML versions of the Article have been modified accordingly.
Mandibular-pelvic-patellar syndrome (mpp) is a novel pitx1-related disorder due to alteration of pitx1 transactivation ability
International audience; PITX1 is a homeobox transcription factor essential for hindlimb morphogenesis. Two PITX1-related human disorders have been reported to date: PITX1 ectopic expression causes Liebenberg syndrome, characterized by malformation of upper limbs showing a "lower limb" appearance; PITX1 deletions or missense variation cause a syndromic picture including clubfoot, tibial hemimelia, and preaxial polydactyly. We report two novel PITX1 missense variants, altering PITX1 transactivation ability, in three individuals from two unrelated families showing a distinct recognizable autosomal dominant syndrome, including first branchial arch, pelvic, patellar, and male genital abnormaliti…
Care management in a French cohort with Down syndrome from the AnDDI-Rares/CNSA study.
Down syndrome (DS) is a genetic neurodevelopmental disorder. In individuals with DS, a multidisciplinary approach to care is required to prevent multiple medical complications. The aim of this study was to describe the rehabilitation, medical care, and educational and social support provided to school-aged French DS patients with varying neuropsychological profiles. A mixed study was conducted. Quantitative data were obtained from a French multicentre study that included patients aged 4-20 years with diverse genetic syndromes. Qualitative data were collected by semi-structured face-to-face interviews and focus groups. Ninety-five DS subjects with a mean age of 10.9 years were included. Sixt…
LARP7 variants and further delineation of the Alazami syndrome phenotypic spectrum among primordial dwarfisms: 2 sisters.
Abstract Alazami syndrome (AS) (MIM# 615071 ) is an autosomal recessive microcephalic primordial dwarfism (PD) with recognizable facial features and severe intellectual disability due to depletion or loss of function variants in LARP7. To date, 15 patients with AS have been reported. Here we describe two consanguineous Algerian sisters with Alazami PD due to LARP7 homozygous pathogenic variants detected by whole exome sequencing. By comparing these two additional cases with those previously reported, we strengthen the key features of AS: severe growth restriction, severe intellectual disability and some distinguishing facial features such as broad nose, malar hypoplasia, wide mouth, full li…
Search forReCQL4mutations in 39 patients genotyped for suspected Rothmund-Thomson/Baller-Gerold syndromes
Three overlapping conditions, namely Rothmund-Thomson (RTS), Baller-Gerold (BGS) and RAPADILINO syndromes, have been attributed to RECQL4 mutations. Differential diagnoses depend on the clinical presentation, but the numbers of known genes remain low, leading to the widespread prescription of RECQL4 sequencing. The aim of our study was therefore to determine the best clinical indicators for the presence of RECQL4 mutations in a series of 39 patients referred for RECQL4 molecular analysis and belonging to the RTS (27 cases) and BGS (12 cases) spectrum. One or two deleterious RECQL4 mutations were found in 10/27 patients referred for RTS diagnosis. Clinical and molecular reevaluation led to a…
Secondary findings from whole-exome/genome sequencing evaluating stakeholder perspectives. A review of the literature
IF 2.004 (2017); International audience; With the development of next generation sequencing, beyond identifying the cause of manifestations that justified prescription of the test, other information with potential interest for patients and their families, defined as secondary findings (SF), can be provided once patients have given informed consent, in particular when therapeutic and preventive options are available. The disclosure of such findings has caused much debate. The aim of this work was to summarize all opinion-based studies focusing on SF, so as to shed light on the concerns that this question generate. A review of the literature was performed, focusing on all PubMed articles repo…
Lysosomal Signaling Licenses Embryonic Stem Cell Differentiation via Inactivation of Tfe3
International audience; Self-renewal and differentiation of pluripotent murine embryonic stem cells (ESCs) is regulated by extrinsic signaling pathways. It is less clear whether cellular metabolism instructs developmental progression. In an unbiased genome-wide CRISPR/Cas9 screen, we identified components of a conserved amino-acid-sensing pathway as critical drivers of ESC differentiation. Functional analysis revealed that lysosome activity, the Ragulator protein complex, and the tumor-suppressor protein Folliculin enable the Rag GTPases C and D to bind and seclude the bHLH transcription factor Tfe3 in the cytoplasm. In contrast, ectopic nuclear Tfe3 represses specific developmental and met…
Clinical and molecular spectrum of renal malformations in Kabuki syndrome.
International audience; OBJECTIVE: To determine the frequency and types of renal malformations, and to evaluate renal function in a cohort of patients with Kabuki syndrome (KS). STUDY DESIGN: Renal ultrasound scans and plasma creatinine measurements were collected from a French cohort of 94 patients with genotyped KS. Renal function was evaluated based on the estimated glomerular filtration rate. A genotype-phenotype study was conducted for renal and urinary tract malformations. RESULTS: Renal malformations were present in 22% of cases, and urinary tract anomalies were present in 15%. Renal malformations were observed in 28% of the MLL2 mutation-positive group and in 0% of the MLL2 mutation…
Associations between cognitive performance and the rehabilitation, medical care and social support provided to French children with Prader-Willi syndrome
International audience; Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental disorder with a characteristic behavioural phenotype. A multidisciplinary approach to care is required to prevent multiple medical complications in individuals affected by PWS. The aim of this study was to describe the rehabilitation, medical care, educational and social support provided to school-aged French PWS patients with varying neuropsychological profiles. Data were obtained from a French multicentre study that included patients aged 4-20 years with diverse genetic syndromes. Nineteen PWS subjects with a mean age of 9.2 years were included. The mean full-scale intellectual quotient (IQ) was 58 (W…
Evaluation of DNA Methylation Episignatures for Diagnosis and Phenotype Correlations in 42 Mendelian Neurodevelopmental Disorders
Contains fulltext : 218274.pdf (Publisher’s version ) (Closed access) Genetic syndromes frequently present with overlapping clinical features and inconclusive or ambiguous genetic findings which can confound accurate diagnosis and clinical management. An expanding number of genetic syndromes have been shown to have unique genomic DNA methylation patterns (called "episignatures"). Peripheral blood episignatures can be used for diagnostic testing as well as for the interpretation of ambiguous genetic test results. We present here an approach to episignature mapping in 42 genetic syndromes, which has allowed the identification of 34 robust disease-specific episignatures. We examine emerging pa…
Molecular diagnosis of PIK3CA-related overgrowth spectrum (PROS) in 162 patients and recommendations for genetic testing.
Postzygotic activating mutations of PIK3CA cause a wide range of mosaic disorders collectively referred to as PIK3CA-related overgrowth spectrum (PROS). We describe the diagnostic yield and characteristics of PIK3CA sequencing in PROS. We performed ultradeep next-generation sequencing (NGS) of PIK3CA in various tissues from 162 patients referred to our clinical laboratory and assessed diagnostic yield by phenotype and tissue tested. We identified disease-causing mutations in 66.7% (108/162) of patients, with mutant allele levels as low as 1%. The diagnostic rate was higher (74%) in syndromic than in isolated cases (35.5%; P = 9.03 × 10−5). We identified 40 different mutations and found stro…
Wiedemann-Steiner syndrome as a major cause of syndromic intellectual disability: A study of 33 French cases.
International audience; Wiedemann-Steiner syndrome (WSS) is a rare syndromic condition in which intellectual disability (ID) is associated with hypertrichosis cubiti, short stature, and characteristic facies. Following the identification of the causative gene (KMT2A) in 2012, only 31 cases of WSS have been described precisely in the literature. We report on 33 French individuals with a KMT2A mutation confirmed by targeted gene sequencing, high-throughput sequencing or exome sequencing. Patients' molecular and clinical features were recorded and compared with the literature data. On the molecular level, we found 29 novel mutations. We observed autosomal dominant transmission of WSS in 3 fami…