Raoul C M Hennekam

University of Amsterdam, Amsterdamo, North Holland, Netherlands

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Publications (474)2414.29 Total impact

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    ABSTRACT: Frontometaphyseal dysplasia (FMD) is a distinctive sclerosing skeletal dysplasia associated with a number of non-skeletal manifestations including hearing loss, cardiac malformations, and stenosis, particularly of the upper airway and urinary tract. Some, but not all, patients have mutations in FLNA causing the condition. Consonant with the X chromosomal location of FLNA males are generally more severely affected than females. FLNA mutations can be detected in 82% of affected males. We describe seven patients (one male, six females) all of whom have the major clinical and radiological features of FMD, but without detectable mutations in FLNA. The females in our cohort are affected to a similar degree as is usually found in males. In addition, all patients have marked keloid formation at various body sites, including the eye, from an early age. Other features that may indicate a different etiology in these patients are the increased frequency of cleft palate, Robin sequence, tracheal stenosis, and mild intellectual disability, which all occur in three of more patients in the present group. All patients are isolated. We hypothesize that the presently reported patients represent further evidence that phenotypes strongly resembling FMD exist that are not accounted for by mutations in FLNA. Since the frequency of several of the manifestations, their sporadic presentations, and the presence of keloid formation differ from the X-linked form of this condition we propose de novo autosomal dominant acting mutations in a gene functionally related to FLNA, underpin this disorder. © 2015 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 04/2015; DOI:10.1002/ajmg.a.37044 · 2.05 Impact Factor
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    ABSTRACT: Tricho-rhino-phalangeal syndrome (TRPS) is characterized by craniofacial and skeletal abnormalities, and subdivided in TRPS I, caused by mutations in TRPS1, and TRPS II, caused by a contiguous gene deletion affecting (amongst others) TRPS1 and EXT1. We performed a collaborative international study to delineate phenotype, natural history, variability, and genotype - phenotype correlations in more detail. We gathered information on 103 cytogenetically or molecularly confirmed affected individuals. TRPS I was present in 85 individuals (22 missense mutations, 62 other mutations), TRPS II in 14, and in 5 it remained uncertain whether TRPS1 was partially or completely deleted. Main features defining the facial phenotype include fine and sparse hair, thick and broad eyebrows, especially the medial portion, a broad nasal ridge and tip, underdeveloped nasal alae, and a broad columella. The facial manifestations in patients with TRPS I and TRPS II do not show a significant difference. In the limbs the main findings are short hands and feet, hypermobility, and a tendency for isolated metacarpals and metatarsals to be shortened. Nails of fingers and toes are typically thin and dystrophic. The radiological hallmark are the cone-shaped epiphyses and in TRPS II multiple exostoses. Osteopenia is common in both, as is reduced linear growth, both prenatally and postnatally. Variability for all findings, also within a single family, can be marked. Morbidity mostly concerns joint problems, manifesting in increased or decreased mobility, pain and in a minority an increased fracture rate. The hips can be markedly affected at a (very) young age. Intellectual disability is uncommon in TRPS I and, if present, usually mild. In TRPS II intellectual disability is present in most but not all, and again typically mild to moderate in severity. Missense mutations are located exclusively in exon 6 and 7 of TRPS1. Other mutations are located anywhere in exons 4-7. Whole gene deletions are common but have variable breakpoints. Most of the phenotype in patients with TRPS II is explained by the deletion of TRPS1 and EXT1, but haploinsufficiency of RAD21 is also likely to contribute. Genotype-phenotype studies showed that mutations located in exon 6 may have somewhat more pronounced facial characteristics and more marked shortening of hands and feet compared to mutations located elsewhere in TRPS1, but numbers are too small to allow firm conclusions. Copyright © 2015. Published by Elsevier Masson SAS.
    European journal of medical genetics 03/2015; 58(5). DOI:10.1016/j.ejmg.2015.03.002 · 1.49 Impact Factor
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    ABSTRACT: Hydrops fetalis is an excessive fluid accumulation within the fetal extra vascular compartments and body cavities. Non-immune hydrops fetalis (NIHF), due to causes other than Rh alloimmunization, is the cause in >85% of all affected individuals. Herein we present an update of our earlier systematic literature review [Bellini et al., 2009] using all publications between 2007 and 2013. We excluded most of the initial 31,783 papers by using strict selection criteria, thus resulting in 24 relevant NIHF publications describing 1,338 individuals with NIHF. We subdivided the affected individuals into 14 classification groups based on the cause of NIHF (percentage of the total group): Cardiovascular (20.1%), Hematologic (9.3%), Chromosomal (9.0%), Syndromic (5.5%), Lymphatic Dysplasia (15.0%), Inborn Errors of Metabolism (1.3%), Infections (7.0%), Thoracic (2.3%), Urinary Tract Malformations (0.9%), Extra Thoracic Tumors (0.7%), TTTF-Placental (4.1%), Gastrointestinal (1.3%), Miscellaneous (3.6%), Idiopathic (19.8%). We discuss the results of the review. There may be some shifts in the percentages of etiological categories as compared to the previous review, but the small numbers within each category make drawing firm conclusions hazardous. We highlight the need for multi-center series of NIHF cases collected and classified using the same schemes in diagnostic work-ups to allow for comparisons of larger numbers of cases. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 02/2015; 167(5). DOI:10.1002/ajmg.a.36988 · 2.05 Impact Factor
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    ABSTRACT: Freeman-Sheldon syndrome, or distal arthrogryposis type 2A (DA2A), is an autosomal-dominant condition caused by mutations in MYH3 and characterized by multiple congenital contractures of the face and limbs and normal cognitive development. We identified a subset of five individuals who had been putatively diagnosed with "DA2A with severe neurological abnormalities" and for whom congenital contractures of the limbs and face, hypotonia, and global developmental delay had resulted in early death in three cases; this is a unique condition that we now refer to as CLIFAHDD syndrome. Exome sequencing identified missense mutations in the sodium leak channel, non-selective (NALCN) in four families affected by CLIFAHDD syndrome. We used molecular-inversion probes to screen for NALCN in a cohort of 202 distal arthrogryposis (DA)-affected individuals as well as concurrent exome sequencing of six other DA-affected individuals, thus revealing NALCN mutations in ten additional families with "atypical" forms of DA. All 14 mutations were missense variants predicted to alter amino acid residues in or near the S5 and S6 pore-forming segments of NALCN, highlighting the functional importance of these segments. In vitro functional studies demonstrated that NALCN alterations nearly abolished the expression of wild-type NALCN, suggesting that alterations that cause CLIFAHDD syndrome have a dominant-negative effect. In contrast, homozygosity for mutations in other regions of NALCN has been reported in three families affected by an autosomal-recessive condition characterized mainly by hypotonia and severe intellectual disability. Accordingly, mutations in NALCN can cause either a recessive or dominant condition characterized by varied though overlapping phenotypic features, perhaps based on the type of mutation and affected protein domain(s). Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.
    The American Journal of Human Genetics 02/2015; DOI:10.1016/j.ajhg.2015.01.003 · 10.99 Impact Factor
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    ABSTRACT: Cornelia de Lange syndrome (CdLS) is characterized by facial dysmorphism, growth failure, intellectual disability, limb malformations and multiple organ involvement. Mutations in five genes, encoding subunits of the cohesin complex (SMC1A, SMC3, RAD21) and its regulators (NIPBL, HDAC8), account for at least 70% of patients with CdLS or CdLS-like phenotypes. To date, only the clinical features from a single CdLS patient with SMC3 mutation has been published. Here, we report the efforts of an international research and clinical collaboration to provide clinical comparison of sixteen patients with CdLS-like features caused by mutations in SMC3. Modelling of the mutation effects on protein structure suggests a dominant-negative effect on the multimeric cohesin complex. When compared to typical CdLS, many SMC3-associated phenotypes are also characterized by postnatal microcephaly but with a less distinctive craniofacial appearance, a milder prenatal growth retardation that worsens in childhood, few congenital heart defects and an absence of limb deficiencies. While most mutations are unique, two unrelated affected individuals shared the same mutation but presented with different phenotypes. This work confirms that de novo SMC3 mutations account for ∼1-2% of CdLS-like phenotypes. This article is protected by copyright. All rights reserved.
    Human Mutation 02/2015; DOI:10.1002/humu.22761 · 5.05 Impact Factor
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    ABSTRACT: Background Myoclonus-dystonia (M-D) is a hyperkinetic movement disorder with predominant myoclonic symptoms combined with dystonia of the upper part of the body. A proportion of M-D cases are caused by mutations in the epsilon-sarcoglycan gene. In remaining M-D patients, no genetic factor has been established, indicating genetic heterogeneity.Methods Patients were included in a prospective clinical database and recruited from referral centers and general neurology clinics in The Netherlands. To investigate new genetic causal factors in M-D syndrome, we performed homozygosity mapping combined with exome sequencing in a three-generation M-D family and genetically screened 24 additional patients with M-D.ResultsWe found co-segregation of the rare missense variant Thr1904Met in the RELN gene. By additional screening of an M-D cohort, we identified co-segregation of RELN variants in two families (Thr1904Met, Ile1217Met) and identified two sporadic RELN mutation carriers (Pro1703Arg, Leu411Ile). Taken together, five of 25 SGCE-negative M-D patients carried RELN rare missense variants.Conclusion We propose that RELN mutations contribute to the genetic heterogeneity of M-D. Reelin is a large secreted glycoprotein that plays essential roles in the cytoarchitecture of laminated brain structures and modulation of synaptic transmission and plasticity. © 2015 International Parkinson and Movement Disorder Society
    Movement Disorders 02/2015; 30(3):n/a-n/a. DOI:10.1002/mds.26070 · 5.63 Impact Factor
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    ABSTRACT: Implementation of next-generation DNA sequencing (NGS) technology into routine diagnostic genome care requires strategic choices. Instead of theoretical discussions on the consequences of such choices, we compared NGS-based diagnostic practices in eight clinical genetic centers in the Netherlands, based on genetic testing of nine pre-selected patients with cardiomyopathy. We highlight critical implementation choices, including the specific contributions of laboratory and medical specialists, bioinformaticians and researchers to diagnostic genome care, and how these affect interpretation and reporting of variants. Reported pathogenic mutations were consistent for all but one patient. Of the two centers that were inconsistent in their diagnosis, one reported to have found 'no causal variant', thereby underdiagnosing this patient. The other provided an alternative diagnosis, identifying another variant as causal than the other centers. Ethical and legal analysis showed that informed consent procedures in all centers were generally adequate for diagnostic NGS applications that target a limited set of genes, but not for exome- and genome-based diagnosis. We propose changes to further improve and align these procedures, taking into account the blurring boundary between diagnostics and research, and specific counseling options for exome- and genome-based diagnostics. We conclude that alternative diagnoses may infer a certain level of 'greediness' to come to a positive diagnosis in interpreting sequencing results. Moreover, there is an increasing interdependence of clinic, diagnostics and research departments for comprehensive diagnostic genome care. Therefore, we invite clinical geneticists, physicians, researchers, bioinformatics experts and patients to reconsider their role and position in future diagnostic genome care.
    European Journal of HumanGenetics 01/2015; DOI:10.1038/ejhg.2014.279 · 4.23 Impact Factor
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    ABSTRACT: Type 2 collagen disorders encompass a diverse group of skeletal dysplasias that are commonly associated with orthopedic, ocular, and hearing problems. However, the frequency of many clinical features has never been determined. We retrospectively investigated the clinical, radiological, and genotypic data in a group of 93 patients with molecularly confirmed SEDC or a related disorder. The majority of the patients (80/93) had short stature, with radiological features of SEDC (n = 64), others having SEMD (n = 5), Kniest dysplasia (n = 7), spondyloperipheral dysplasia (n = 2), or Torrance-like dysplasia (n = 2). The remaining 13 patients had normal stature with mild SED, Stickler-like syndrome or multiple epiphyseal dysplasia. Over 50% of the patients had undergone orthopedic surgery, usually for scoliosis, femoral osteotomy or hip replacement. Odontoid hypoplasia was present in 56% (95% CI 38-74) and a correlation between odontoid hypoplasia and short stature was observed. Atlanto-axial instability, was observed in 5 of the 18 patients (28%, 95% CI 10-54) in whom flexion-extension films of the cervical spine were available; however, it was rarely accompanied by myelopathy. Myopia was found in 45% (95% CI 35-56), and retinal detachment had occurred in 12% (95% CI 6-21; median age 14 years; youngest age 3.5 years). Thirty-two patients complained of hearing loss (37%, 95% CI 27-48) of whom 17 required hearing aids. The ophthalmological features and possibly also hearing loss are often relatively frequent and severe in patients with splicing mutations. Based on clinical findings, age at onset and genotype-phenotype correlations in this cohort, we propose guidelines for the management and follow-up in this group of disorders.
    American Journal of Medical Genetics Part A 01/2015; 167(3). DOI:10.1002/ajmg.a.36922 · 2.05 Impact Factor
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    ABSTRACT: Singleton-Merten syndrome (SMS) is an infrequently described autosomal-dominant disorder characterized by early and extreme aortic and valvular calcification, dental anomalies (early-onset periodontitis and root resorption), osteopenia, and acro-osteolysis. To determine the molecular etiology of this disease, we performed whole-exome sequencing and targeted Sanger sequencing. We identified a common missense mutation, c.2465G>A (p.Arg822Gln), in interferon induced with helicase C domain 1 (IFIH1, encoding melanoma differentiation-associated protein 5 [MDA5]) in four SMS subjects from two families and a simplex case. IFIH1 has been linked to a number of autoimmune disorders, including Aicardi-Goutières syndrome. Immunohistochemistry demonstrated the localization of MDA5 in all affected target tissues. In vitro functional analysis revealed that the IFIH1 c.2465G>A mutation enhanced MDA5 function in interferon beta induction. Interferon signature genes were upregulated in SMS individuals' blood and dental cells. Our data identify a gain-of-function IFIH1 mutation as causing SMS and leading to early arterial calcification and dental inflammation and resorption. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.
    The American Journal of Human Genetics 01/2015; 96(2). DOI:10.1016/j.ajhg.2014.12.014 · 10.99 Impact Factor
  • European journal of human genetics: EJHG 12/2014; DOI:10.1038/ejhg.2014.270 · 4.23 Impact Factor
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    ABSTRACT: Dihydropyrimidine dehydrogenase (DPD) deficiency is an autosomal recessive disorder of the pyrimidine metabolism. Deficiency of this enzyme leads to an accumulation of thymine and uracil and a deficiency of metabolites distal to the catabolic enzyme. The disorder presents with a wide clinical spectrum, ranging from asymptomatic to severe neurological manifestations, including intellectual disability, seizures, microcephaly, autistic behavior, and eye abnormalities. Here, we report on an 11-year-old Malaysian girl and her 6-year-old brother with DPD deficiency who presented with intellectual disability, microcephaly, and hypotonia. Brain MRI scans showed generalized cerebral and cerebellar atrophy and callosal body dysgenesis in the boy. Urine analysis showed strongly elevated levels of uracil in the girl and boy (571 and 578 mmol/mol creatinine, respectively) and thymine (425 and 427 mmol/mol creatinine, respectively). Sequence analysis of the DPYD gene showed that both siblings were homozygous for the mutation c.1651G>A (pAla551Thr).
    Molecular syndromology 12/2014; 5(6):299-303. DOI:10.1159/000366074
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    ABSTRACT: The internet pre-eminently marks an era with unprecedented chances for patient care. Especially individuals with rare disorders and their families can benefit. Their handicap of low numbers vanishes and can become a strength, as small, motivated and well-organized international support groups allow easily fruitful collaborations with physicians and researchers. Jointly setting research agendas and building wikipedias has eventually led to building of multi-lingual databases of longitudinal data on physical and behavioural characteristics of individuals with several rare disorders which we call waihonapedias (waihona meaning treasure in Hawaiian). There are hurdles to take, like online security and reliability of diagnoses, but sharing experiences and true collaborations will allow better research and patient care for fewer costs to patients with rare disorders. Copyright © 2014. Published by Elsevier Masson SAS.
    European Journal of Medical Genetics 11/2014; 58(1). DOI:10.1016/j.ejmg.2014.10.006 · 1.49 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 11/2014; 164(11). DOI:10.1002/ajmg.a.36713 · 2.05 Impact Factor
  • Journal of Cranio-Maxillofacial Surgery 11/2014; DOI:10.1016/j.jcms.2014.10.015 · 2.60 Impact Factor
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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; DOI:10.1038/tpj.2014.68 · 5.51 Impact Factor
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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; 24(4). DOI:10.1093/hmg/ddu513 · 6.68 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 09/2014; 35(9). DOI:10.1002/humu.22603 · 5.05 Impact Factor
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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 09/2014; 164A(9). DOI:10.1002/ajmg.a.36654 · 2.05 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 09/2014; 166(3). DOI:10.1002/ajmg.c.31409 · 3.54 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 09/2014; 164(9). DOI:10.1002/ajmg.a.36668 · 2.05 Impact Factor

Publication Stats

15k Citations
2,414.29 Total Impact Points


  • 1993–2015
    • University of Amsterdam
      • • Department of Paediatrics
      • • Faculty of Medicine AMC
      Amsterdamo, North Holland, Netherlands
    • Leiden University
      Leyden, South Holland, Netherlands
  • 2014
    • Cedars-Sinai Medical Center
      • Medical Genetics Institute
      Los Angeles, California, United States
  • 1993–2014
    • Academisch Medisch Centrum Universiteit van Amsterdam
      • • Department of Paediatrics
      • • Academic Medical Center
      • • Department of Clinical Genetics
      Amsterdamo, North Holland, Netherlands
  • 2013
    • Baylor College of Medicine
      • Department of Molecular & Human Genetics
      Houston, Texas, United States
  • 1994–2013
    • Academic Medical Center (AMC)
      Amsterdamo, North Holland, Netherlands
  • 2011
    • Université René Descartes - Paris 5
      Lutetia Parisorum, Île-de-France, France
  • 2005–2011
    • Great Ormond Street Hospital for Children NHS Foundation Trust
      • Department of Clinical Genetics
      Londinium, England, United Kingdom
    • French Institute of Health and Medical Research
      Lutetia Parisorum, Île-de-France, France
    • Unité Inserm U1077
      Caen, Lower Normandy, France
  • 2010
    • Ghent University
      • Department of Molecular Biotechnology
      Gent, VLG, Belgium
    • Maastricht University
      Maestricht, Limburg, Netherlands
    • University College London
      • Institute of Child Health
      Londinium, England, United Kingdom
  • 2009
    • Institute for Child Health Policy (ICHP)
      Florida, United States
    • IRCCS Ospedale Casa Sollievo della Sofferenza
      Giovanni Rotondo, Apulia, Italy
  • 2005–2009
    • National Human Genome Research Institute
      Maryland, United States
  • 2008
    • University of London
      Londinium, England, United Kingdom
    • University of Washington Seattle
      Seattle, Washington, United States
  • 2007–2008
    • Clinical Molecular Genetics Society
      Londinium, England, United Kingdom
    • St. James University
      Сент-Джеймс, New York, United States
    • UCL Eastman Dental Institute
      Londinium, England, United Kingdom
  • 2006
    • University of the Ryukyus
      Okinawa, Okinawa, Japan
    • Howard Hughes Medical Institute
      Ashburn, Virginia, United States
    • Leiden University Medical Centre
      • Department of Molecular Cell Biology
      Leyden, South Holland, Netherlands
  • 1991–2005
    • University Medical Center Utrecht
      Utrecht, Utrecht, Netherlands
  • 2004
    • Universitair Ziekenhuis Ghent
      • Centre for Medical Genetics
      Gand, Flanders, Belgium
  • 2000
    • Johns Hopkins University
      Baltimore, Maryland, United States
    • Utrecht University
      Utrecht, Utrecht, Netherlands
  • 1996
    • Accare – Kinder- en Jeugdpsychiatrie
      Assen, Drenthe, Netherlands
  • 1992
    • VU University Amsterdam
      Amsterdamo, North Holland, Netherlands
  • 1990
    • University of Utah
      • Department of Pediatrics
      Salt Lake City, UT, United States