Valérie Malan
Necker-Enfants Malades Hospital
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Publication
Featured researches published by Valérie Malan.
Journal of Medical Genetics | 2011
Sabina Benko; Christopher T. Gordon; Delphine Mallet; Rajini Sreenivasan; Christel Thauvin-Robinet; Atle Brendehaug; Sophie Thomas; Ove Bruland; Michel David; Marc Nicolino; Audrey Labalme; Damien Sanlaville; Patrick Callier; Valérie Malan; Frédéric Huet; Frédérique Dijoud; Arnold Munnich; Laurence Faivre; Jeanne Amiel; Vincent R. Harley; Gunnar Houge; Yves Morel; Stanislas Lyonnet
Background The early gonad is bipotential and can differentiate into either a testis or an ovary. In XY embryos, the SRY gene triggers testicular differentiation and subsequent male development via its action on a single gene, SOX9. The supporting cell lineage of the bipotential gonad will differentiate as testicular Sertoli cells if SOX9 is expressed and conversely will differentiate as ovarian granulosa cells when SOX9 expression is switched off. Results Through copy number variation mapping this study identified duplications upstream of the SOX9 gene in three families with an isolated 46,XX disorder of sex development (DSD) and an overlapping deletion in one family with two probands with an isolated 46,XY DSD. The region of overlap between these genomic alterations, and previously reported deletions and duplications at the SOX9 locus associated with syndromic and isolated cases of 46,XX and 46,XY DSD, reveal a minimal non-coding 78 kb sex determining region located in a gene desert 517–595 kb upstream of the SOX9 promoter. Conclusions These data indicate that a non-coding regulatory region critical for gonadal SOX9 expression and subsequent normal sex development is located far upstream of the SOX9 promoter. Its copy number variations are the genetic basis of isolated 46,XX and 46,XY DSDs of variable severity (ranging from mild to complete sex reversal). It is proposed that this region contains a gonad specific SOX9 transcriptional enhancer(s), the gain or loss of which results in genomic imbalance sufficient to activate or inactivate SOX9 gonadal expression in a tissue specific manner, switch sex determination, and result in isolated DSD.
American Journal of Medical Genetics Part A | 2005
Marie-France Portnoï; F. Lebas; Nicolas Gruchy; Azarnouche Ardalan; Valérie Biran-Mucignat; Valérie Malan; Lina Finkel; Gilles Roger; S. Ducrocq; Francis Gold; Jean-Louis Taillemite; Sandrine Marlin
Twenty‐one patients, including our two cases, with variable clinical phenotype, ranging from mild learning disability to severe congenital malformations or overlapping features with DiGeorge/velocardiofacial syndromes (DG/VCFS), have been shown to have a chromosome duplication 22q11 of the region that is deleted in patients with DG/VCFS. The reported cases have been identified primarily by interphase FISH and could have escaped identification and been missed by routine cytogenetic analysis. Here we report on two inherited cases, referred to us, to rule out 22q11 microdeletion diagnosis of VCFS. The first patient was a 2‐month‐old girl, who presented with cleft palate, minor dysmorphic features including short palpebral fissures, widely spaced eyes, long fingers, and hearing loss. Her affected mother had mild mental retardation and learning disabilities. The second patient was a 7½‐year‐old boy with velopharyngeal insufficiency and mild developmental delay. He had a left preauricular tag, bifida uvula, bilateral fifth finger clinodactyly, and bilateral cryptorchidism. His facial features appeared mildly dysmorphic with hypertelorism, large nose, and micro/retrognathia. The affected father had mild mental retardation and had similar facial features. FISH analysis of interphase cells showed three TUPLE1‐probe signals with two chromosome‐specific identification probes in each cell. FISH analysis did not show the duplication on the initial testing of metaphase chromosomes. On review, band q11.2 was brighter on one chromosome 22 in some metaphase spreads. The paucity of reported cases of 22q11.2 microduplication likely reflects a combination of phenotypic diversity and the difficulty of diagnosis by FISH analysis on metaphase spreads. These findings illustrate the importance of scanning interphase nuclei when performing FISH analysis for any of the genomic disorders.
Human Mutation | 2009
Loïc de Pontual; Yves Mathieu; Christelle Golzio; Marlène Rio; Valérie Malan; Nathalie Boddaert; Christine Soufflet; Capucine Picard; Anne Durandy; Angus Dobbie; Delphine Héron; Bertrand Isidor; Jacques Motte; Ruth Newburry‐Ecob; Laurent Pasquier; Marc Tardieu; Géraldine Viot; Francis Jaubert; Arnold Munnich; Laurence Colleaux; Michel Vekemans; Heather Etchevers; Stanislas Lyonnet; Jeanne Amiel
Pitt‐Hopkins syndrome is a severe congenital encephalopathy recently ascribed to de novo heterozygous TCF4 gene mutations. We report a series of 13 novel PHS cases with a TCF4 mutation and show that EEG, brain magnetic resonance imagain (MRI), and immunological investigations provide valuable additional clues to the diagnosis. We confirm a mutational hot spot in the basic domain of the E‐protein. Functional studies illustrate that heterodimerisation of mutant TCF4 proteins with a tissue‐specific transcription factor is less effective than that homodimerisation in a luciferase reporter assay. We also show that the TCF4 expression pattern in human embryonic development is widespread but not ubiquitous. In summary, we further delineate an underdiagnosed mental retardation syndrome, highlighting TCF4 function during development and facilitating diagnosis within the first year of life. Hum Mutat 0, 1–8, 2009.
Pediatrics | 2008
Anne Philippe; Nathalie Boddaert; Laurence Vaivre-Douret; Laurence Robel; Laurent Danon-Boileau; Valérie Malan; Marie-Christine de Blois; Delphine Héron; Laurence Colleaux; Bernard Golse; Monica Zilbovicius; Arnold Munnich
OBJECTIVE. The 22q13.3 deletion syndrome (Online Mendelian Inheritance in Man No. 606232) is a neurodevelopmental disorder that includes hypotonia, severely impaired development of speech and language, autistic-like behavior, and minor dysmorphic features. Although the number of reported cases is increasing, the 22q13.3 deletion remains underdiagnosed because of failure in recognizing the clinical phenotype and detecting the 22qter deletion by routine chromosome analyses. Our goal is to contribute to the description of the neurobehavioral phenotype and brain abnormalities of this microdeletional syndrome. METHODS. We assessed neuromotor, sensory, language, communication, and social development and performed cerebral MRI and study of regional cerebral blood flow measured by positron emission tomography in 8 children carrying the 22q13.3 deletion. RESULTS. Despite variability in expression and severity, the children shared a common developmental profile characterized by hypotonia, sleep disorders, and poor response to their environment in early infancy; expressive language deficit contrasting with emergence of social reciprocity from ages ∼3 to 5 years; sensory processing dysfunction; and neuromotor disorders. Brain MRI findings were normal or showed a thin or morphologically atypical corpus callosum. Positron emission tomography study detected a localized dysfunction of the left temporal polar lobe and amygdala hypoperfusion. CONCLUSIONS. The developmental course of the 22q13.3 deletion syndrome belongs to pervasive developmental disorders but is distinct from autism. An improved description of the natural history of this syndrome should help in recognizing this largely underdiagnosed condition.
Clinical Genetics | 2006
Valérie Malan; Michel Vekemans; Catherine Turleau
The finding of a mixture of 46,XX and 46,XY cells in an individual has been rarely reported in literature. It usually results in individuals with ambiguous genitalia. Approximately 10% of true human hermaphrodites show this type of karyotype. However, the underlying mechanisms are poorly understood. It may be the result of mosaicism or chimerism. By definition, a chimera is produced by the fusion of two different zygotes in a single embryo, while a mosaic contains genetically different cells issued from a single zygote. Several mechanisms are involved in the production of chimera. Stricto sensu, chimerism occurs from the post‐zygotic fusion of two distinct embryos leading to a tetragametic chimera. In addition, there are other entities, which are also referred to as chimera: parthenogenetic chimera and chimera resulting from fertilization of the second polar body. Furthermore, a particular type of chimera called ‘androgenetic chimera’ recently described in fetuses with placental mesenchymal dysplasia and in rare patients with Beckwith–Wiedemann syndrome is discussed. Strategies to study mechanisms leading to the production of chimera and mosaics are also proposed.
Journal of Medical Genetics | 2012
Christopher T. Gordon; Florence Petit; Myriam Oufadem; Charles Decaestecker; Anne-Sophie Jourdain; Joris Andrieux; Valérie Malan; Jean-Luc Alessandri; Geneviève Baujat; Clarisse Baumann; Odile Boute-Benejean; Roseline Caumes; Bruno Delobel; Klaus Dieterich; Dominique Gaillard; Marie Gonzales; Didier Lacombe; Fabienne Escande; Sylvie Manouvrier-Hanu; Sandrine Marlin; Michèle Mathieu-Dramard; Sarju G. Mehta; Ingrid Simonic; Arnold Munnich; Michel Vekemans; Nicole Porchet; Loïc de Pontual; Sabine Sarnacki; Tania Attié-Bitach; Stanislas Lyonnet
Background: Oesophageal atresia (OA) and mandibulofacial dysostosis (MFD) are two congenital malformations for which the molecular bases of syndromic forms are being identified at a rapid rate. In particular, the EFTUD2 gene encoding a protein of the spliceosome complex has been found mutated in patients with MFD and microcephaly (MIM610536). Until now, no syndrome featuring both MFD and OA has been clearly delineated. Results: We report on 10 cases presenting with MFD, eight of whom had OA, either due to de novo 17q21.31 deletions encompassing EFTUD2 and neighbouring genes or de novo heterozygous EFTUD2 loss-of-function mutations. No EFTUD2 deletions or mutations were found in a series of patients with isolated OA or isolated oculoauriculovertebral spectrum (OAVS). Conclusions: These data exclude a contiguous gene syndrome for the association of MFD and OA, broaden the spectrum of clinical features ascribed to EFTUD2 haploinsufficiency, define a novel syndromic OA entity, and emphasise the necessity of mRNA maturation through the spliceosome complex for global growth and within specific regions of the embryo during development. Importantly, the majority of patients reported here with EFTUD2 lesions were previously diagnosed with Feingold or CHARGE syndromes or presented with OAVS plus OA, highlighting the variability of expression and the wide range of differential diagnoses.
European Journal of Medical Genetics | 2010
Feng Li; Yiping Shen; Udo Köhler; Freddie H. Sharkey; Deepa Menon; Laurence Coulleaux; Valérie Malan; Marlène Rio; Dominic J. McMullan; Helen Cox; Kerry A. Fagan; Lorraine Gaunt; Kay Metcalfe; Uwe Heinrich; Gordon Hislop; Una Maye; Maxine Sutcliffe; Bai-Lin Wu; Brian D. Thiel; Surabhi Mulchandani; Laura K. Conlin; Nancy B. Spinner; Kathleen M. Murphy; Denise Batista
The use of comparative genomic hybridization (CGH) and single nucleotide polymorphism (SNP) arrays has dramatically altered the approach to identification of genetic alterations that can explain intellectual disability and /or congenital anomalies. However, the discovery of numerous copy number changes with benign or unknown clinical significance has made interpretation problematic. Submicroscopic duplication of Xp22.31 has been reported as either a possible cause of intellectual disability and/or developmental delay or a benign variant. Here we report 29 individuals with the microduplication found as part of microarray analysis of 7793 samples submitted to an international group of 13 clinical laboratories. The referral reasons varied and included developmental delay, intellectual disability, autism, dysmorphic features and/or multiple congenital anomalies. The size of the Xp22.31 duplication varied between 149 kb and 1.74 Mb and included the steroid sulfatase (STS) gene with the male to female ratio of 0.7. Duplication within this segment is seen at a frequency of 0.15% in a healthy control population, whereas a frequency of 0.37% was observed in our cohort of individuals with abnormal phenotypes. We present a detailed comparison of the breakpoints, inheritance, X-inactivation and clinical phenotype in our cohort and a review of the literature for a total of 41 patients. To date, this report is the largest compilation of clinical and array data regarding the microduplication of Xp22.31 and will serve to broaden the knowledge of regions involving copy number variation (CNV).
Journal of Medical Genetics | 2010
Céline Bonnet; Joris Andrieux; Mylène Béri-Dexheimer; Bruno Leheup; Odile Boute; S Manouvrier; Bruno Delobel; Henri Copin; Aline Receveur; Michèle Mathieu; G Thiriez; C Le Caignec; A David; Mc De Blois; Valérie Malan; Anne Philippe; Valérie Cormier-Daire; Laurence Colleaux; Elisabeth Flori; H Dollfus; V Pelletier; Christel Thauvin-Robinet; Alice Masurel-Paulet; L. Faivre; Marc Tardieu; Nadia Bahi-Buisson; Patrick Callier; Francine Mugneret; Philippe Jonveaux; D. Sanlaville
Background Genome-wide screening of large patient cohorts with mental retardation using microarray-based comparative genomic hybridisation (array-CGH) has recently led to identification several novel microdeletion and microduplication syndromes. Methods Owing to the national array-CGH network funded by the French Ministry of Health, shared information about patients with rare disease helped to define critical intervals and evaluate their gene content, and finally determine the phenotypic consequences of genomic array findings. Results In this study, nine unrelated patients with overlapping de novo interstitial microdeletions involving 4q21 are reported. Several major features are common to all patients, including neonatal muscular hypotonia, severe psychomotor retardation, marked progressive growth restriction, distinctive facial features and absent or severely delayed speech. The boundaries and the sizes of the nine deletions are different, but an overlapping region of 1.37 Mb is defined; this region contains five RefSeq genes: PRKG2, RASGEF1B, HNRNPD, HNRPDL and ENOPH1. Discussion Adding new individuals with similar clinical features and 4q21 deletion allowed us to reduce the critical genomic region encompassing two genes, PRKG2 and RASGEF1B. PRKG2 encodes cGMP-dependent protein kinase type II, which is expressed in brain and in cartilage. Information from genetically modified animal models is pertinent to the clinical phenotype. RASGEF1B is a guanine nucleotide exchange factor for Ras family proteins, and several members have been reported as key regulators of actin and microtubule dynamics during both dendrite and spine structural plasticity. Conclusion Clinical and molecular delineation of 4q21 deletion supports a novel microdeletion syndrome and suggests a major contribution of PRKG2 and RASGEF1B haploinsufficiency to the core phenotype.
Journal of Medical Genetics | 2009
Valérie Malan; O Raoul; Helen V. Firth; Ghislaine Royer; Catherine Turleau; Alain Bernheim; Lionel Willatt; Arnold Munnich; Michel Vekemans; Stanislas Lyonnet; Valérie Cormier-Daire; Laurence Colleaux
Background: Deletions of chromosome 19 have rarely been reported, with the exception of some patients with deletion 19q13.2 and Blackfan–Diamond syndrome due to haploinsufficiency of the RPS19 gene. Such a paucity of patients might be due to the difficulty in detecting a small rearrangement on this chromosome that lacks a distinct banding pattern. Array comparative genomic hybridisation (CGH) has become a powerful tool for the detection of microdeletions and microduplications at high resolution in patients with syndromic mental retardation. Methods and results: Using array CGH, this study identified three interstitial overlapping 19q13.11 deletions, defining a minimal critical region of 2.87 Mb, associated with a clinically recognisable syndrome. The three patients share several major features including: pre- and postnatal growth retardation with slender habitus, severe postnatal feeding difficulties, microcephaly, hypospadias, signs of ectodermal dysplasia, and cutis aplasia over the posterior occiput. Interestingly, these clinical features have also been described in a previously reported patient with a 19q12q13.1 deletion. No recurrent breakpoints were identified in our patients, suggesting that no-allelic homologous recombination mechanism is not involved in these rearrangements. Conclusions: Based on these results, the authors suggest that this chromosomal abnormality may represent a novel clinically recognisable microdeletion syndrome caused by haploinsufficiency of dosage sensitive genes in the 19q13.11 region.
European Journal of Human Genetics | 2009
Céline Huber; Anee-Lise Delezoide; Fabien Guimiot; Clarisse Baumann; Valérie Malan; Martine Le Merrer; Daniela Bezerra Da Silva; Dominique Bonneau; Pierre G. Chatelain; Carol Chu; Robin Clark; Helen Cox; Patrick Edery; Thomas Edouard; Virginia Fano; Kate Gibson; Gabriele Gillessen-Kaesbach; Maria-Luisa Giovannucci-Uzielli; Luitgard Graul-Neumann; Johana-Maria van Hagen; Liselot van Hest; Dafne Horovitz; Judith Melki; Carl-Joachim Partsch; H. Plauchu; Anna Rajab; Massimiliano Rossi; David Sillence; Elisabeth Steichen-Gersdorf; Helen Stewart
The 3M syndrome is a rare autosomal recessive disorder recently ascribed to mutations in the CUL7 gene and characterized by severe pre- and postnatal growth retardation. Studying a series of 33 novel cases of 3M syndrome, we have identified deleterious CUL7 mutations in 23/33 patients, including 19 novel mutations and one paternal isodisomy of chromosome 6 encompassing a CUL7 mutation. Lack of mutations in 10/33 cases and exclusion of the CUL7 locus on chromosome 6p21.1 in six consanguineous families strongly support the genetic heterogeneity of the 3M syndrome.