Raoul C M Hennekam

Cedars-Sinai Medical Center, Los Angeles, California, United States

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Publications (462)2338.67 Total impact

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    ABSTRACT: Dihydropyrimidine dehydrogenase is a crucial enzyme for the degradation of 5-fluorouracil (5FU). DPYD, which encodes dihydropyrimidine dehydrogenase, is prone to acquire genomic rearrangements because of the presence of an intragenic fragile site FRA1E. We evaluated DPYD copy number variations (CNVs) in a prospective series of 242 stage I-III colorectal tumours (including 87 patients receiving 5FU-based treatment). CNVs in one or more exons of DPYD were detected in 27% of tumours (deletions or amplifications of one or more DPYD exons observed in 17% and 10% of cases, respectively). A significant relationship was observed between the DPYD intragenic rearrangement status and dihydropyrimidine dehydrogenase (DPD) mRNA levels (both at the tumour level). The presence of somatic DPYD aberrations was not associated with known prognostic or predictive biomarkers, except for LOH of chromosome 8p. No association was observed between DPYD aberrations and patient survival, suggesting that assessment of somatic DPYD intragenic rearrangement status is not a powerful biomarker to predict the outcome of 5FU-based chemotherapy in patients with colorectal cancer.The Pharmacogenomics Journal advance online publication, 28 October 2014; doi:10.1038/tpj.2014.68.
    The pharmacogenomics journal. 10/2014;
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    ABSTRACT: Using exome sequencing and linkage analysis in a 3-generation family with an unique dominant Mycolonus-Dystonia-like syndrome with cardiac arrhythmias we identified a mutation in the CACNA1B gene, coding for neuronal voltage-gated calcium channels CaV2.2. This mutation (c.4166G>A;p.Arg1389His) is a disruptive missense mutation in the outer region of the ion pore. The functional consequences of the identified mutation was studied using whole cell and single channel patch recordings. High resolution analyses at the single channel level showed that, when open, R1389H CaV2.2 channels carried less current compared to WT channels. Other biophysical channel properties were unaltered in R1389H channels including ion selectivity, voltage-dependent activation or voltage-dependent inactivation. CaV2.2 channels regulate transmitter release at inhibitory and excitatory synapses. Functional changes could be consistent with a gain-of-function causing the observed hyperexcitability characteristic of this unique Myoclonus-Dystonia-like syndrome associated with cardiac arrhythmias.
    Human Molecular Genetics 10/2014; · 7.69 Impact Factor
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    ABSTRACT: BACKGROUND: Cornelia de Lange syndrome (CdLS) is a multisystem disorder with distinctive facial appearance, intellectual disability and growth failure as prominent features. Most individuals with typical CdLS have de novo heterozygous loss-of-function mutations in NIPBL with mosaic individuals representing a significant proportion. Mutations in other cohesin components, SMC1A, SMC3, HDAC8 and RAD21 cause less typical CdLS. METHODS: We screened 163 affected individuals for coding region mutations in the known genes, 90 for genomic rearrangements, 19 for deep intronic variants in NIPBL and 5 had whole-exome sequencing. RESULTS: Pathogenic mutations [including mosaic changes] were identified in: NIPBL 46 [3] (28.2%); SMC1A 5 [1] (3.1%); SMC3 5 [1] (3.1%); HDAC8 6 [0] (3.6%) and RAD21 1 [0] (0.6%). One individual had a de novo 1.3 Mb deletion of 1p36.3. Another had a 520 kb duplication of 12q13.13 encompassing ESPL1, encoding separase, an enzyme that cleaves the cohesin ring. Three de novo mutations were i
    Journal of Medical Genetics 08/2014; · 5.70 Impact Factor
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    ABSTRACT: We describe an adolescent Peruvian male with marked, aggressive ingrowth of conjunctiva (pterygium-like) over the cornea associated with keloid formation on his distal limbs. He has in addition camptodactyly of all fingers and to some extent of his toes, and unusual skin pigmentations. He resembles an earlier described family from Norway in which a mother and two children showed a similar combination of signs. We present the follow-up of the Norwegian family. The entity resembles the Penttinen syndrome but can be differentiated due to the early aging in the latter, which is lacking in the presently reported entity. We suggest naming this entity ocular pterygium–digital keloid dysplasia. The condition follows likely an autosomal dominant pattern of inheritance. © 2014 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 08/2014; · 2.30 Impact Factor
  • Philippe M. Campeau, Raoul C. Hennekam
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    ABSTRACT: DOORS syndrome (Deafness, Onychodystrophy, Osteodystrophy, mental Retardation, Seizures) is characterized mainly by sensorineural deafness, shortened terminal phalanges with small nails of hands and feet, intellectual deficiency, and seizures. Half of the patients with all clinical features have mutations in TBC1D24. We review here the manifestations of patients clinically diagnosed with DOORS syndrome. In this cohort of 32 families (36 patients) we detected 13 individuals from 10 families with TBC1D24 mutations. Subsequent whole exome sequencing in the cohort showed the same de novoSMARCB1 mutation (c.1130G>A), known to cause Coffin-Siris syndrome, in two patients. Distinguishing features include retinal anomalies, Dandy-Walker malformation, scoliosis, rocker bottom feet, respiratory difficulties and absence of seizures, and 2-oxoglutaric aciduria in the patients with the SMARCB1 mutation. We briefly discuss the heterogeneity of the DOORS syndrome phenotype and the differential diagnosis of this condition. © 2014 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part C Seminars in Medical Genetics 08/2014; · 4.44 Impact Factor
  • Sérgio B. Sousa, Raoul C. Hennekam
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    ABSTRACT: Nicolaides–Baraitser syndrome (NCBRS) is an intellectual disability (ID)/multiple congenital anomalies syndrome caused by non-truncating mutations in the ATPase region of SMARCA2, which codes for one of the two alternative catalytic subunits of the BAF chromatin remodeling complex. We analyzed 61 molecularly confirmed cases, including all previously reported patients (n = 47) and 14 additional unpublished individuals. NCBRS is clinically and genetically homogeneous. The cardinal features (ID, short stature, microcephaly, typical face, sparse hair, brachydactyly, prominent interphalangeal joints, behavioral problems and seizures), are almost universally present. There is variability however, as ID can range from severe to mild, and sparse hair may be present only in certain age groups. There may be a correlation between the severity of the ID and presence of seizures, absent speech, short stature and microcephaly. SMARCA2 mutations causing NCBRS are likely to act through a dominant-negative effect. There may be some genotype–phenotype correlations (mutations at domain VI with severe ID and seizures; mutations affecting residues Pro883, Leu946, and Ala1201 with mild phenotypes) but numbers are still too small to draw definitive conclusions. © 2014 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part C Seminars in Medical Genetics 08/2014; · 4.44 Impact Factor
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    ABSTRACT: Background Rubinstein-Taybi syndrome (RSTS) is a multiple congenital anomalies-intellectual disability syndrome. One of the complications is keloid formation. Keloids are proliferative fibrous growths resulting from excessive tissue response to skin trauma.Objectives To describe the clinical characteristics of keloids in individuals with RSTS reported in literature and in a cohort of personally evaluated RSTS individuals.Methods We performed a literature search for descriptions of RSTS individuals with keloids. All known RSTS individuals in the Netherlands filled out three dedicated questionnaires. All individuals with (possible) keloids were personally evaluated. A further series of RSTS individuals from the UK were personally evaluated.ResultsReliable data were available on 62 of the 83 Dutch RSTS individuals and showed 15 RSTS individuals (24%) to have keloids. The 15 Dutch and 12 UK RSTS individuals with keloids demonstrated that most patients have multiple keloids (n>1: 82%; n>5: 30%). Mean age of onset is 11.9 years. The majority are located on shoulders and chest. Mean length x width of the largest keloid was 7.1 x 2.8 cm, mean thickness was 0.7 cm. All affected individuals complained of itching. Generally, treatment results were disappointing.Conclusions Keloids occur in 24% of individuals with RSTS, either spontaneously or after a minor trauma, usually starting in early puberty. Management schedules have disappointing results. RSTS is a Mendelian disorder of known molecular basis, and offers excellent opportunities to study the pathogenesis of keloids in general and search for treatments.This article is protected by copyright. All rights reserved.
    British Journal of Dermatology 08/2014; · 3.76 Impact Factor
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    ABSTRACT: Primrose syndrome and 3q13.31 microdeletion syndrome are clinically related disorders characterized by tall stature, macrocephaly, intellectual disability, disturbed behavior and unusual facial features, with diabetes, deafness, progressive muscle wasting and ectopic calcifications specifically occurring in the former. We report that missense mutations in ZBTB20, residing within the 3q13.31 microdeletion syndrome critical region, underlie Primrose syndrome. This finding establishes a genetic link between these disorders and delineates the impact of ZBTB20 dysregulation on development, growth and metabolism.
    Nature genetics. 07/2014;
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    ABSTRACT: Rubinstein–Taybi syndrome (RSTS) is an autosomal dominant disorder characterized by variable degrees of intellectual disability, an unusual face, distal limb anomalies including broad thumbs and broad halluces, a large group of variable other major and minor anomalies, and decreased somatic growth. The aim of the present study was to construct up-to-date growth charts specific for infants and children with RSTS. We collected retrospective growth data of 92 RSTS individuals of different ancestries. Data were corrected for secular trends and population of origin to the Dutch growth charts of 2009. On average, 17.9 measurements were available per individual. Height, weight and body mass index (BMI) references for males and females were constructed using the lambda, mu, sigma method. RSTS individuals had normal birth weight and length. Mean final heights were 162.6 cm [−2.99 standard deviation score (SDS)] for males and 151.0 cm [−3.01 SDS] for females. BMI SDS compared to the general Dutch population were −0.06 and 1.40 SDS for males and females, respectively. Head circumference SDS compared to the general Dutch population was −1.89 SDS for males and −2.71 SDS for females. This is the first study to publish growth charts using only molecularly proven RSTS individuals. These syndrome-specific growth charts can be used in managing problems related to growth in RSTS individuals. © 2014 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 07/2014; · 2.30 Impact Factor
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    ABSTRACT: We report on a series of 514 consecutive diagnoses of skeletal dysplasia made over an 8-year period at a tertiary hospital in Kerala, India. The most common diagnostic groups were dysostosis multiplex group (n = 73) followed by FGFR3 (n = 49) and osteogenesis imperfecta and decreased bone density group (n = 41). Molecular confirmation was obtained in 109 cases. Clinical and radiographic evaluation was obtained in close diagnostic collaboration with expert groups abroad through Internet communication for difficult cases. This has allowed for targeted biochemical and molecular studies leading to the correct identification of rare or novel conditions, which has not only helped affected families by allowing for improved genetic counseling and prenatal diagnosis but also resulted in several scientific contributions. We conclude that (1) the spectrum of genetic bone disease in Kerala, India, is similar to that of other parts of the world, but recessive entities may be more frequent because of widespread consanguinity; (2) prenatal detection of skeletal dysplasias remains relatively rare because of limited access to expert prenatal ultrasound facilities; (3) because of the low accessibility to molecular tests, precise clinical-radiographic phenotyping remains the mainstay of diagnosis and counseling and of gatekeeping to efficient laboratory testing; (4) good phenotyping allows, a significant contribution to the recognition and characterization of novel entities. We suggest that the tight collaboration between a local reference center with dedicated personnel and expert diagnostic networks may be a proficient model to bring current diagnostics to developing countries. © 2014 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 07/2014; · 2.30 Impact Factor
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    ABSTRACT: Marshall-Smith syndrome (MSS) is a very rare malformation syndrome characterized by typical craniofacial anomalies, abnormal osseous maturation, developmental delay, failure to thrive, and respiratory difficulties. Mutations in the nuclear factor 1/X gene (NFIX) were recently identified as the cause of MSS. In our study cohort of 17 patients with a clinical diagnosis of MSS, conventional sequencing of NFIX revealed frameshift and splice-site mutations in 10 individuals. Using multiplex ligation-dependent probe amplification (MLPA) analysis, we identified a recurrent deletion of NFIX exon 6 and 7 in five individuals. We demonstrate this recurrent deletion is the product of a recombination between AluY elements located in intron 5 and 7. Two other patients had smaller deletions affecting exon 6. These findings show that MSS is a genetically homogeneous Mendelian disorder. RT-PCR experiments with newly identified NFIX mutations including the recurrent exon 6 and 7 deletion confirmed previous findings indicating that MSS-associated mutant mRNAs are not cleared by nonsense mediated mRNA decay. Predicted MSS-associated mutant NFIX proteins consistently have a preserved DNA binding and dimerization domain, whereas they grossly vary in their C-terminal portion. This is in line with the hypothesis that MSS-associated mutations encode dysfunctional proteins that act in a dominant negative manner. This article is protected by copyright. All rights reserved.
    Human Mutation 06/2014; · 5.21 Impact Factor
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    ABSTRACT: The Hennekam lymphangiectasia-lymphedema syndrome is a genetically heterogeneous disorder. It can be caused by mutations in CCBE1 which are found in approximately 25 % of cases. We used homozygosity mapping and whole-exome sequencing in the original HS family with multiple affected individuals in whom no CCBE1 mutation had been detected, and identified a homozygous mutation in the FAT4 gene. Subsequent targeted mutation analysis of FAT4 in a cohort of 24 CCBE1 mutation-negative Hennekam syndrome patients identified homozygous or compound heterozygous mutations in four additional families. Mutations in FAT4 have been previously associated with Van Maldergem syndrome. Detailed clinical comparison between van Maldergem syndrome and Hennekam syndrome patients shows that there is a substantial overlap in phenotype, especially in facial appearance. We conclude that Hennekam syndrome can be caused by mutations in FAT4 and be allelic to Van Maldergem syndrome.
    Human genetics. 06/2014;
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    ABSTRACT: Sequencing technology is increasingly demonstrating the impact of genomic copy number variation (CNV) on phenotypes. Opposing variation in growth, head size, cognition and behaviour is known to result from deletions and reciprocal duplications of some genomic regions. We propose normative inversion of face shape, opposing difference from a matched norm, as a basis for investigating the effects of gene dosage on craniofacial development. We use dense surface modelling techniques to match any face (or part of a face) to a facial norm of unaffected individuals of matched age, sex and ethnicity and then we reverse the individual’s face shape differences from the matched norm to produce the normative inversion. We demonstrate for five genomic regions, 4p16.3, 7q11.23, 11p15, 16p13.3 and 17p11.2, that such inversion for individuals with a duplication or (epi)-mutation produces facial forms remarkably similar to those associated with a deletion or opposite (epi-)mutation of the same region, and vice versa. The ability to visualise and quantify face shape effects of gene dosage is of major benefit for determining whether a CNV is the cause of the phenotype of an individual and for predicting reciprocal consequences. It enables face shape to be used as a relatively simple and inexpensive functional analysis of the gene(s) involved.
    Human Genetics 06/2014; · 4.63 Impact Factor
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    ABSTRACT: Dienoyl-CoA reductase (DECR) deficiency with hyperlysinemia is a rare disorder affecting the metabolism of polyunsaturated fatty acids and lysine. The molecular basis of this condition is currently unknown. We describe a new case with failure to thrive, developmental delay, lactic acidosis and severe encephalopathy suggestive of a mitochondrial disorder. Exome sequencing revealed a causal mutation in NADK2. NADK2 encodes the mitochondrial NAD kinase, which is crucial for NADP biosynthesis evidenced by decreased mitochondrial NADP(H) levels in patient fibroblasts. DECR and also the first step in lysine degradation are performed by NADP-dependent oxidoreductases explaining their in vivo deficiency. DECR activity was also deficient in lysates of patient fibroblasts and could only be rescued by transfecting patient cells with functional NADK2. Thus NADPH is not only crucial as a cosubstrate, but can also act as a molecular chaperone that activates and stabilizes enzymes. In addition to polyunsaturated fatty acid oxidation and lysine degradation, NADPH also plays a role in various other mitochondrial processes. We found decreased oxygen consumption and increased extracellular acidification in patient fibroblasts, which may explain why the disease course is consistent with clinical criteria for a mitochondrial disorder. We conclude that DECR deficiency with hyperlysinemia is caused by mitochondrial NADP(H) deficiency due to a mutation in NADK2.
    Human Molecular Genetics 05/2014; · 7.69 Impact Factor
  • Fonnet E Bleeker, Saskia M Hopman, Raoul C Hennekam
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    ABSTRACT: In many malformation syndromes benign and malignant tumours develop more frequently than in the general population. Malformations result from an abnormal intrinsic developmental process. It can be hypothesized that disturbed regulation of cell growth as can become evident by the presence of benign and malignant tumours, which will occur at the same site of a malformation or at other sites at which the gene involved in the malformation is functioning. The present study aimed to compare the localization of malignant and benign tumours to the localization of major and minor characteristics of syndromes that have either of two malformations, i.e. microtia and hypospadias. To eliminate co-occurrence of a malformation syndrome and tumours by chance we confined evaluations to syndromes which have been described in >100 individuals. We identified 11 syndromes associated with microtia and 26 syndromes associated with hypospadias, for which co-localisation of (benign and malignant) tumours with (major and minor) syndrome characteristics was determined. In both groups of syndromes tumours were found to be localized at the same body site as the major and minor characteristics of the syndromes in two-third of the tumours. There was no significant difference in co-occurrence in site between benign and malignant tumours. We conclude that in two groups of malformation syndromes which go along with a different core malformation, benign and malignant tumours co-localize with the core malformation or with other sites at which the gene involved is functioning. This adds further proof that tumours in malformation syndromes can usually be explained by abnormal functioning of the same gene that has caused the malformation syndrome.
    European journal of medical genetics 04/2014; · 1.57 Impact Factor
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    ABSTRACT: GGCX mutations have been reported in patients with a pseudoxanthoma elasticum (PXE)-like phenotype, loose redundant skin, with multiple Vitamin K-dependent coagulation factor deficiencies. We report on the clinical findings and molecular results in 13 affected members of two families who had a uniform phenotype consisting of (PXE)-like skin manifestations in neck and trunk, loose sagging skin of trunk and upper limbs, and retinitis pigmentosa (RP) confirmed by ElectroRetinoGraphies in 10 affected individuals. There were no coagulation abnormalities. Molecular investigations of the ATP-Binding Cassette subfamily C member 6 (ABCC6) did not yield causative mutations. All 13 affected family members were found to be homozygous for the splice-site mutation c.373+3 G>T in the Gamma-Glutamyl carboxylase (GGCX) gene. All tested parents were heterozygous for the mutation, and healthy siblings were either heterozygous or had the wild-type. We suggest that the present patients represent a hitherto unreported phenotype associated with GGCX mutations. Di-genic inheritance has been suggested to explain the variability in phenotype in GGCX mutation carriers. Consequently, the present phenotype may not be explained only by the GGCX mutations only but may be influenced by variants in other genes or epigenetic and environmental factors.Journal of Investigative Dermatology accepted article peview online, 16 April 2014. doi:10.1038/jid.2014.191.
    Journal of Investigative Dermatology 04/2014; · 6.19 Impact Factor
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    ABSTRACT: (Brain) tumors are usually a disorder of aged individuals. If a brain tumor occurs in a child, there is a possible genetic susceptibility for this. Such genetic susceptibilities often show other signs and symptoms. Therefore, every child with a brain tumor should be carefully evaluated for the presence of a "tumor predisposition syndrome." Here, we provide an overview of the various central nervous system tumors that occur in children with syndromes and of the various syndromes that occur in children with brain tumor. Our aim is to facilitate recognition of syndromes in children with a brain tumor and early diagnosis of brain tumors in children with syndromes. Diagnosing tumor predisposition syndromes in children may have important consequences for prognosis, treatment, and screening for subsequent malignancies and nontumor manifestations. We discuss pitfalls in clinical and molecular diagnoses, and the consequences of diagnosing a hereditary disorder for family members. Our improved knowledge of cancer etiology is increasingly translated into management strategies in syndromes in general and will likely lead in the near future to personalized therapeutic approaches for tumor predisposition syndromes.
    Neuropediatrics 02/2014; · 1.19 Impact Factor
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    ABSTRACT: Myhre syndrome is characterized by short stature, brachydactyly, facial features, pseudomuscular hypertrophy, joint limitation and hearing loss. We identified SMAD4 mutations as the cause of Myhre syndrome. SMAD4 mutations have also been identified in laryngotracheal stenosis, arthropathy, prognathism and short stature syndrome (LAPS). This study aimed to review the features of Myhre and LAPS patients to define the clinical spectrum of SMAD4 mutations. We included 17 females and 15 males ranging in age from 8 to 48 years. Thirty were diagnosed with Myhre syndrome and two with LAPS. SMAD4 coding sequence was analyzed by Sanger sequencing. Clinical and radiological features were collected from a questionnaire completed by the referring physicians. All patients displayed a typical facial gestalt, thickened skin, joint limitation and muscular pseudohypertrophy. Growth retardation was common (68.7%) and was variable in severity (from -5.5 to -2 SD), as was mild-to-moderate intellectual deficiency (87.5%) with additional behavioral problems in 56.2% of the patients. Significant health concerns like obesity, arterial hypertension, bronchopulmonary insufficiency, laryngotracheal stenosis, pericarditis and early death occurred in four. Twenty-nine patients had a de novo heterozygous SMAD4 mutation, including both patients with LAPS. In 27 cases mutation affected Ile500 and in two cases Arg496. The three patients without SMAD4 mutations had typical findings of Myhre syndrome. Myhre-LAPS syndrome is a clinically homogenous condition with life threatening complications in the course of the disease. Our identification of SMAD4 mutations in 29/32 cases confirms that SMAD4 is the major gene responsible for Myhre syndrome.European Journal of Human Genetics advance online publication, 15 January 2014; doi:10.1038/ejhg.2013.288.
    European journal of human genetics: EJHG 01/2014; · 3.56 Impact Factor

Publication Stats

13k Citations
2,338.67 Total Impact Points

Institutions

  • 2014
    • Cedars-Sinai Medical Center
      • Medical Genetics Institute
      Los Angeles, California, United States
  • 1993–2014
    • University of Amsterdam
      • • Faculty of Medicine AMC
      • • Department of Paediatrics
      Amsterdamo, North Holland, Netherlands
    • Academisch Medisch Centrum Universiteit van Amsterdam
      • • Department of Clinical Genetics
      • • Department of Plastic and Reconstructive Surgery
      • • Department of Clinical Chemistry
      • • Department of Paediatrics
      • • Department of Cardiology and Cardio-thoracic Surgery
      • • Department of Neonatology
      Amsterdamo, North Holland, Netherlands
  • 2013
    • Baylor College of Medicine
      • Department of Molecular & Human Genetics
      Houston, Texas, United States
    • University of Toronto
      • Division of Clinical and Metabolic Genetics
      Toronto, Ontario, Canada
    • Hospitais da Universidade de Coimbra
      Coímbra, Coimbra, Portugal
  • 2010–2013
    • Università degli Studi di Torino
      • Dipartimento di Scienze della Sanità Pubblica e Pediatriche
      Torino, Piedmont, Italy
    • University of Birmingham
      • School of Psychology
      Birmingham, ENG, United Kingdom
  • 2012
    • University of Utah
      • Department of Pediatrics
      Salt Lake City, UT, United States
    • Kariminejad & Najmabadi Pathology and Genetics Center
      Teheran, Tehrān, Iran
  • 2010–2012
    • UCL Eastman Dental Institute
      Londinium, England, United Kingdom
  • 2006–2012
    • University College London
      • • Department of Clinical and Experimental Epilepsy
      • • Institute of Child Health
      • • Centre for Cell Signalling and Molecular Genetics
      London, ENG, United Kingdom
    • Università degli Studi di Genova
      • Dipartimento di Scienze Politiche (DISPO)
      Genova, Liguria, Italy
    • Howard Hughes Medical Institute
      Ashburn, Virginia, United States
  • 2005–2012
    • Academic Medical Center (AMC)
      Amsterdamo, North Holland, Netherlands
    • Great Ormond Street Hospital for Children NHS Foundation Trust
      • Department of Clinical Genetics
      Londinium, England, United Kingdom
    • University of Groningen
      • Department of Clinical Genetics
      Groningen, Province of Groningen, Netherlands
    • Children's Hospital of Tunis
      Tunis-Ville, Tūnis, Tunisia
  • 2011
    • Lentis
      Amsterdamo, North Holland, Netherlands
    • Amrita Institute of Medical Sciences and Research Centre
      • Department of Pediatric Genetics
      Cochin, Kerala, India
    • Wroclaw Medical University
      • Department of Genetics
      Wrocław, Lower Silesian Voivodeship, Poland
  • 2010–2011
    • Ghent University
      • Department of Molecular Biotechnology
      Gent, VLG, Belgium
  • 2007–2011
    • University of Washington Seattle
      • • Department of Pediatrics
      • • Department of Genome Sciences
      Seattle, WA, United States
    • Ludwig Boltzmann Institute for Osteology
      Wien, Vienna, Austria
    • Groene Hart Ziekenhuis
      Guda, South Holland, Netherlands
  • 2005–2011
    • Université René Descartes - Paris 5
      • Faculté de Médecine
      Lutetia Parisorum, Île-de-France, France
  • 2003–2011
    • Leiden University Medical Centre
      • • Department of Clinical Genetics
      • • Department of Molecular Cell Biology
      Leiden, South Holland, Netherlands
    • Erasmus Universiteit Rotterdam
      • Department of Clinical Genetics
      Rotterdam, South Holland, Netherlands
  • 2006–2010
    • Tohoku University
      • Department of Medical Genetics
      Sendai, Kagoshima, Japan
  • 2009
    • Institute for Child Health Policy (ICHP)
      Florida, United States
    • Schneider Children's Medical Center of Israel
      Petah Tikva, Central District, Israel
    • IRCCS Ospedale Casa Sollievo della Sofferenza
      Giovanni Rotondo, Apulia, Italy
    • Haukeland University Hospital
      • Centre for Medical Genetics and Molecular Medicine
      Bergen, Hordaland, Norway
  • 2005–2009
    • National Human Genome Research Institute
      Maryland, United States
  • 1997–2009
    • Children's Hospital of Eastern Ontario
      Ottawa, Ontario, Canada
  • 1993–2009
    • Leiden University
      • Faculty of Social and Behavioural Sciences
      Leiden, South Holland, Netherlands
  • 2008
    • Hospital Egas Moniz
      Lisboa, Lisbon, Portugal
    • WWF United Kingdom
      Londinium, England, United Kingdom
    • The Bracton Centre, Oxleas NHS Trust
      Дартфорде, England, United Kingdom
  • 2007–2008
    • University of London
      Londinium, England, United Kingdom
    • Clinical Molecular Genetics Society
      Londinium, England, United Kingdom
  • 2004
    • Universitair Ziekenhuis Ghent
      • Centre for Medical Genetics
      Gand, Flanders, Belgium
  • 2000
    • IRCCS Istituto G. Gaslini
      Genova, Liguria, Italy
  • 1997–2000
    • Johns Hopkins University
      Baltimore, Maryland, United States
  • 1990–2000
    • Utrecht University
      Utrecht, Utrecht, Netherlands
  • 1998
    • Columbia University
      • Department of Obstetrics and Gynecology
      New York City, NY, United States
  • 1992–1997
    • VU University Amsterdam
      • Department of Clinical Genetics
      Amsterdam, North Holland, Netherlands
  • 1996
    • Accare – Kinder- en Jeugdpsychiatrie
      Assen, Drenthe, Netherlands
    • Klinički Bolnički Centar Split
      • Department of Pediatrics
      Split, Splitsko-Dalmatinska Zupanija, Croatia
  • 1990–1992
    • University Medical Center Utrecht
      Utrecht, Utrecht, Netherlands