Christian T Thiel

Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Bavaria, Germany

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Publications (43)271.07 Total impact

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    ABSTRACT: Numerous genes are involved in human growth regulation. Recently, autosomal recessive inherited variants in centrosomal proteins have been identified in Seckel syndrome, primary microcephaly or microcephalic osteodysplastic primary dwarfism. Common hallmarks of these syndromic forms are severe short stature and microcephaly. In a consanguineous family with two affected children with severe growth retardation and normocephaly we used homozygosity mapping and next generation sequencing to identify a homozygous MAP4 variant. MAP4 is a major protein for microtubule assembly during mitosis. High expression levels in the somite boundaries of zebrafish suggested a role in growth and body segment patterning. The identified variant affects binding sites of kinases necessary for dynamic instability of microtubule formation. We found centrosome amplifications in mitotic fibroblast cells in vivo and in vitro. These numeric centrosomal aberrations were also present during interphase resulting in aberrant ciliogenesis. Furthermore, affected cells showed a dysfunction of the microtubule dependent assembly of the Golgi apparatus, indicated by a significant lack of compactness of Golgi membranes. These observations demonstrated that MAP4 mutations contribute to the clinical spectrum of centrosomal defects and confirmed the complex role of a centrosomal protein in centrosomal, ciliary and Golgi regulation associated with severe short stature. This article is protected by copyright. All rights reserved.
    Human Mutation 10/2014; · 5.21 Impact Factor
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    ABSTRACT: Despite abundant evidence for pathogenicity of large copy number variants (CNVs) in neurodevelopmental disorders (NDDs), the individual significance of genome-wide rare CNVs <500 kb has not been well elucidated in a clinical context.
    Journal of medical genetics. 08/2014;
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    ABSTRACT: Germline mutation testing in patients with colorectal cancer (CRC) is offered only to a subset of patients with a clinical presentation or tumor histology suggestive of familial CRC syndromes, probably underestimating familial CRC predisposition. The aim of our study was to determine whether unbiased screening of newly diagnosed CRC cases with next generation sequencing (NGS) increases the overall detection rate of germline mutations. We analyzed 152 consecutive CRC patients for germline mutations in 18 CRC-associated genes using NGS. All patients were also evaluated for Bethesda criteria and all tumors were investigated for microsatellite instability, immunohistochemistry for mismatch repair proteins and the BRAF*V600E somatic mutation. NGS based sequencing identified 27 variants in 9 genes in 23 out of 152 patients studied (18%). 3 of them were already reported as pathogenic and 12 were class 3 germline variants with an uncertainprediction of pathogenicity. Only 1 of these patients fulfilled Bethesda criteria and had a microsatellite instable tumor and an MLH1 germline mutation. The others would have been missed with current approaches:2 with a MSH6 premature termination mutation and 12 uncertain, potentially pathogenic class 3 variants in APC, MLH1, MSH2, MSH6, MSH3 and MLH3 The higher NGS mutation detection rate compared to current testing strategies based on clinicopathological criteria probably is due to the large genetic heterogeneity and overlapping clinical presentation of the various CRC syndromes. It can also identify apparently non-penetrant germline mutations complicating the clinical management of the patients and their families. © 2014 Wiley Periodicals, Inc.
    International Journal of Cancer 08/2014; · 6.20 Impact Factor
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    ABSTRACT: Osteogenesis imperfecta is a heritable connective tissue disorder characterized by variable symptoms including predisposition to fractures. Despite the identification of numerous mutations, a reliable genotype-phenotype correlation has remained notoriously difficult. We now describe two patients with osteogenesis imperfecta and novel, so far undescribed mutations in the COL1A2 gene, further highlighting this complexity. A 3-year-old patient presented with features reminiscent of a connective tissue disorder, with joint hypermobility, Wormian bones, streaky lucencies in the long bones and relative macrocephaly. The patient carried a heterozygous c.1316G > A (p.Gly439Asp) mutation in the COL1A2 gene located in a triple-helix region, in which glycine substitutions have been assumed to cause perinatal lethal OI (Sillence type II). A second family with type I osteogenesis imperfecta carried a heterozygous nonsense mutation c.4060C > T (p.Gln1354X) within the last exon of COL1A2. Whereas other heterozygous nonsense mutations in COL1A2 do not lead to a phenotype, in this case the mRNA is presumed to escape nonsense-mediated decay. Therefore the predicted COL1A2 propeptide lacks the last 13 C-terminal amino acids, suggesting that the OI phenotype results from decelerated assembly and overmodification of the collagen triple helix. The presented COL1A2 mutations exemplify the complexity of COL1A2 genotype-phenotype correlation in genetic counselling in OI.
    European journal of medical genetics 10/2013; · 1.57 Impact Factor
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    ABSTRACT: Chromosomal microarray testing is commonly used to identify disease causing de novo copy number variants in patients with developmental delay and multiple congenital anomalies. In such a patient we now observed an 150 kb deletion on chromosome 7q21.11 affecting the first exon of the axon guidance molecule gene SEMA3A (sema domain, immunoglobulin domain (Ig), short basic domain, secreted, (semaphorin) 3A). This deletion was inherited from the healthy father, but considering the function of SEMA3A and phenotypic similarity to the knock-out mice, we still assumed a pathogenic relevance and tested for a recessive second defect. Sequencing of SEMA3A in the patient indeed revealed the de novo in-frame mutation p.Phe316_Lys317delinsThrSerSerAsnGlu. Cloning of the mutated allele in combination with two informative SNPs confirmed compound heterozygosity in the patient. While the altered protein structure was predicted to be benign, aberrant splicing resulting in a premature stop codon was proven by RT-PCR to occur in about half of the transcripts from this allele. Expression profiling in human fetal and adult cDNA panels, confirmed a high expression of SEMA3A in all brain regions as well as in adult and fetal heart and fetal skeletal muscle. Normal intellectual development in the patient was surprising but may be explained by the remaining 20% of SEMA3A expression level demonstrated by quantitative RT-PCR. We therefore report a novel autosomal recessive syndrome characterized by postnatal short stature with relative macrocephaly, camptodactyly, septal heart defect and several minor anomalies caused by biallelic mutations in SEMA3A. © 2013 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 10/2013; · 2.30 Impact Factor
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    ABSTRACT: We report on two patients with a severe form of spondyloepimetaphyseal dysplasia (SEMD). Both patients show normal birth length, early postnatal growth deficiency, severe short stature, flexion contractures in the hips, bowing of the legs with genu varum. Skeletal radiographies show platyspondyly and characteristic vertebral body shape with central indentation of endplates, progressive, and severe metaphyseal changes, very small and irregular proximal femoral epiphyses with severe coxa vara, absence of calcifications, and mild metaphyseal irregularities in upper limbs. The similarities in the skeletal radiographs with SEMD type Strudwick and SEMD matrilin 3 type prompted us to analyze the COL2A1 and MATN3 genes. Direct sequencing of genomic DNA failed to identify any mutation in COL2A1 for both patients and MATN3 sequencing for Patient 1 identified only one heterozygous variant with no predicted damaging effect inherited from an unaffected parent. We therefore conclude that this form of SEMD probably differs from SEMD matrilin 3 type and does not belong to the spectrum of type II collagenopathies. The similarities between our two patients allowed us to propose that they might show a new form of SEMD. © 2013 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 08/2013; · 2.30 Impact Factor
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    ABSTRACT: Human growth has an estimated heritability of about 80%-90%. Nevertheless, the underlying cause of shortness of stature remains unknown in the majority of individuals. Genome-wide association studies (GWAS) showed that both common single nucleotide polymorphisms and copy number variants (CNVs) contribute to height variation under a polygenic model, although explaining only a small fraction of overall genetic variability in the general population. Under the hypothesis that severe forms of growth retardation might also be caused by major gene effects, we searched for rare CNVs in 200 families, 92 sporadic and 108 familial, with idiopathic short stature compared to 820 control individuals. Although similar in number, patients had overall significantly larger CNVs (p-value<1×10(-7)). In a gene-based analysis of all non-polymorphic CNVs>50 kb for gene function, tissue expression, and murine knock-out phenotypes, we identified 10 duplications and 10 deletions ranging in size from 109 kb to 14 Mb, of which 7 were de novo (p<0.03) and 13 inherited from the likewise affected parent but absent in controls. Patients with these likely disease causing 20 CNVs were smaller than the remaining group (p<0.01). Eleven (55%) of these CNVs either overlapped with known microaberration syndromes associated with short stature or contained GWAS loci for height. Haploinsufficiency (HI) score and further expression profiling suggested dosage sensitivity of major growth-related genes at these loci. Overall 10% of patients carried a disease-causing CNV indicating that, like in neurodevelopmental disorders, rare CNVs are a frequent cause of severe growth retardation.
    PLoS Genetics 03/2013; 9(3):e1003365. · 8.52 Impact Factor
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    ABSTRACT: BACKGROUND: The genetic cause of intellectual disability in most patients is unclear because of the absence of morphological clues, information about the position of such genes, and suitable screening methods. Our aim was to identify de-novo variants in individuals with sporadic non-syndromic intellectual disability. METHODS: In this study, we enrolled children with intellectual disability and their parents from ten centres in Germany and Switzerland. We compared exome sequences between patients and their parents to identify de-novo variants. 20 children and their parents from the KORA Augsburg Diabetes Family Study were investigated as controls. FINDINGS: We enrolled 51 participants from the German Mental Retardation Network. 45 (88%) participants in the case group and 14 (70%) in the control group had de-novo variants. We identified 87 de-novo variants in the case group, with an exomic mutation rate of 1·71 per individual per generation. In the control group we identified 24 de-novo variants, which is 1·2 events per individual per generation. More participants in the case group had loss-of-function variants than in the control group (20/51 vs 2/20; p=0·022), suggesting their contribution to disease development. 16 patients carried de-novo variants in known intellectual disability genes with three recurrently mutated genes (STXBP1, SYNGAP1, and SCN2A). We deemed at least six loss-of-function mutations in six novel genes to be disease causing. We also identified several missense alterations with potential pathogenicity. INTERPRETATION: After exclusion of copy-number variants, de-novo point mutations and small indels are associated with severe, sporadic non-syndromic intellectual disability, accounting for 45-55% of patients with high locus heterogeneity. Autosomal recessive inheritance seems to contribute little in the outbred population investigated. The large number of de-novo variants in known intellectual disability genes is only partially attributable to known non-specific phenotypes. Several patients did not meet the expected syndromic manifestation, suggesting a strong bias in present clinical syndrome descriptions. FUNDING: German Ministry of Education and Research, European Commission 7th Framework Program, and Swiss National Science Foundation.
    The Lancet 09/2012; · 39.21 Impact Factor
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    ABSTRACT: Purpose:Radial ray deficiencies are characterized by unilateral or bilateral absence of varying portions of the radius and thumb. Both isolated and syndromic forms have been described, and although for some of the syndromes the causal gene has been identified, many patients remain without a genetic diagnosis.Methods:In this study, a cohort of 54 patients with radial ray deficiencies was screened for genomic aberrations by molecular karyotyping.Results:In 8 of 54 cases, an aberration was detected. Two unrelated patients inherited a 1q21.1 microduplication from a healthy parent, whereas in a third patient, a 16p13.11 microduplication was identified. Two other interesting microdeletions were detected: a 10q24.3 deletion at the split hand-foot malformation (SHFM3) locus and a 7p22.1 deletion including the RAC1 gene.Conclusion:The finding of these microduplications may just be coincidental or, alternatively, they may illustrate the broad phenotypic spectrum of these microduplications. Duplications in the 10q24.3 region result in split hand-foot malformations, and our observation indicates that deletions may cause radial ray defects. Finally, a candidate gene for radial ray deficiencies was detected in the 7p22.1 deletion. RAC1 plays an important role in the canonical Wnt pathway and conditional RAC1 knockout mice exhibit truncated-limb defects.Genet Med advance online publication 20 September 2012Genetics in Medicine (2012); doi:10.1038/gim.2012.120.
    Genetics in medicine: official journal of the American College of Medical Genetics 09/2012; · 3.92 Impact Factor
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    ABSTRACT: Juvenile angiofibroma (JA) is a unique fibrovascular tumor, which is almost exclusively found in the posterior nasal cavity of adolescent males. Although histologically classified as benign, the tumor often shows an aggressive growth pattern and has been associated with chromosomal imbalances, amplification of oncogenes and epigenetic dysregulation. We present the first genome-wide profiling of JAs (n=14) with a 100K single nucleotide polymorphism (SNP) microarray. Among the 30 novel JA-specific amplifications detected on autosomal chromosomes with this technique, the genes encoding the cancer-testis antigen BORIS (brother of the regulator of imprinted sites) and the developmental regulator protein TSHZ1 (teashirt zinc finger homeobox 1) were selected for further analysis. Gains for both BORIS (20q13.3) and TSHZ1 (18q22.3) were confirmed by quantitative genomic PCR. Furthermore, quantitative RT-PCR revealed a significant up-regulation of BORIS (p<0.001) and TSHZ1 transcripts (p<0.05) for JAs compared to nasal mucosa. Following detection of BORIS and TSHZ1 proteins in western blots of JAs, subcellular localization was determined for both proteins in immunostaining of JA cryosections. In conclusion, genomic copy number profiling using an SNP microarray has been proven to be a suitable and reliable tool for identifying novel disease-related genes in JAs and newly implicates BORIS and TSHZ1 overexpression in the pathogenesis of JAs. Detection of BORIS in JAs is described with special regard to tumor proliferation and epigenetic dysregulation, and the finding of TSHZ1 amplifications is discussed with special respect to the hypothesis of JAs as malformations of the first branchial arch artery.
    International Journal of Oncology 11/2011; 39(5):1143-51. · 2.66 Impact Factor
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    ABSTRACT: Epigenetic regulation of gene expression, through covalent modification of histones, is a key process controlling growth and development. Accordingly, the transcription factors regulating these processes are important targets of genetic diseases. However, surprisingly little is known about the relationship between aberrant epigenetic states, the cellular process affected, and their phenotypic consequences. By chromosomal breakpoint mapping in a patient with a Noonan syndrome-like phenotype that encompassed short stature, blepharoptosis, and attention deficit hyperactivity disorder, we identified haploinsufficiency of the histone acetyltransferase gene MYST histone acetyltransferase (monocytic leukemia) 4 (MYST4), as the underlying cause of the phenotype. Using acetylation, whole genome expression, and ChIP studies in cells from the patient, cell lines in which MYST4 expression was knocked down using siRNA, and the Myst4 querkopf mouse, we found that H3 acetylation is important for neural, craniofacial, and skeletal morphogenesis, mainly through its ability to specifically regulating the MAPK signaling pathway. This finding further elucidates the complex role of histone modifications in mammalian development and adds what we believe to be a new mechanism to the pathogenic phenotypes resulting from misregulation of the RAS signaling pathway.
    The Journal of clinical investigation 08/2011; 121(9):3479-91. · 15.39 Impact Factor
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    ABSTRACT: We report a follow up study on two MOPD II Thai families with severe dental anomalies and hypoplastic alveolar bone. Striking dental anomalies comprise severe microdontia, opalescent and abnormally shaped teeth, and rootless molars. As a result of severe hypoplastic alveolar bone, most permanent teeth have been lost. Mutation analysis of PCNT revealed 2 novel mutations (p.Lys3154del and p.Glu1154X) and a recurrent mutation (p.Pro1923X). Teeth of the patient who carried a homozygous novel mutation of p.Glu1154X are probably the smallest ever reported. The sizes of the mandibular permanent incisors and all premolars were approximately 2-2.5 mm, mesiodistally. All previously reported, PCNT mutations have been described to cause premature truncation of the pericentrin protein. p.Lys3154del mutation was unique as it was pathogenic as a result of missing only a single amino acid. In situ hybridization of Pcnt shows its expression in the epithelium and mesenchyme during early stages of rodent tooth development. It is evident that PCNT has crucial role in tooth development. The permanent dentition is more severely affected than the one. This implies that PCNT appears to have more role in the development of the permanent dentition. As pericentrin is a critical centrosomal protein, the dental phenotype found in MOPD II patients is postulated to be the consequence of loss of microtubule integrity which leads to defective centrosome function.
    American Journal of Medical Genetics Part A 06/2011; 155A(6):1398-403. · 2.30 Impact Factor
  • Christian T Thiel, Anita Rauch
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    ABSTRACT: Cartilage-hair hypoplasia and anauxetic dysplasia are two autosomal recessive skeletal dysplasias characterized by different degrees from metaphyseal to spondylo-meta-epiphyseal dysplasia and variable additional features including predisposition to cancer, anemia, immunodeficiency, and gastrointestinal malabsorption and Hirschsprung's disease. Both are caused by mutations in the untranslated RMRP gene, which forms the RNA subunit of the RNase MRP complex. This complex is involved in the ribosome assembly by cleavage of 5.8S rRNA, cell cycle control by Cyclin B2 mRNA cleavage at the end of mitosis, processing the mitochondrial RNA, and forming a complex with hTERT suggesting a possible involvement in expression regulation by siRNA synthesis. The degree of skeletal dysplasia correlates mainly with the rRNA cleavage activity, whereas significantly diminished mRNA cleavage activity is a prerequisite for immunodeficiency. Thus, the clinical phenotype emerges in most cases of the combined effect on the respective effect on RNase MRP function.
    Best Practice & Research: Clinical Endocrinology & Metabolism 02/2011; 25(1):131-42. · 4.91 Impact Factor
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    ABSTRACT: Defects of ciliogenesis have been implicated in a wide range of human phenotypes and play a crucial role in signal transduction and cell-cycle coordination. We used homozygosity mapping in two families with autosomal-recessive short-rib polydactyly syndrome Majewski type to identify mutations in NEK1 as an underlying cause of this lethal osteochondrodysplasia. NEK1 encodes a serine/threonine kinase with proposed function in DNA double-strand repair, neuronal development, and coordination of cell-cycle-associated ciliogenesis. We found that absence of functional full-length NEK1 severely reduces cilia number and alters ciliar morphology in vivo. We further substantiate a proposed digenic diallelic inheritance of ciliopathies by the identification of heterozygous mutations in NEK1 and DYNC2H1 in an additional family. Notably, these findings not only increase the broad spectrum of ciliar disorders, but suggest a correlation between the degree of defective microtubule or centriole elongation and organization and the severity of the resulting phenotype.
    The American Journal of Human Genetics 01/2011; 88(1):106-14. · 11.20 Impact Factor
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    ABSTRACT: We identified a maternally inherited 14.2Mb duplication 5q22.1-q23.2 in two female siblings and their mother by molecular karyotyping. Both siblings were small for gestational age and presented with pronounced postnatal growth retardation, mild motor delay, congenital heart disease in one of the siblings, and distinct facial dysmorphism. As this duplication is one of the smallest reported 5q duplications, short stature and facial dysmorphism can be attributed to duplications of 5q22, whereas severe mental retardation is not part of the phenotypic spectrum of the 5q22.1-q23.2 region. Congenital heart defects, as observed in other 5q duplications, have a variable penetrance. We compared the facial features of patients with 5q duplications and found some consistent features such as high arched eyebrows, bulbous nasal tip and small lips with thin vermilion border.
    European journal of medical genetics 01/2011; 54(5):e521-4. · 1.57 Impact Factor
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    ABSTRACT: The etiology of non-syndromic hydrocephalus is poorly understood. Via positional cloning in a consanguineous family with autosomal recessive hydrocephalus we have now identified a homozygous splice site mutation in the CCDC88C gene as a novel cause of a complex hydrocephalic brain malformation. The only living patient showed normal psychomotor development at the age of 3 years and 3 months and her deceased aunt, who was assumed to suffer from the same condition, had mild mental retardation. The mutation in the affected patients, a homozygous substitution in the donor splice site of intron 29, resulted in a shorter transcript due to exclusion of exon 29 and loss of functional protein, as shown by Western blotting (p.S1591HfsX7). In normal human tissue panels, we found CCDC88C ubiquitously expressed, but most prominently in the fetal brain, especially in pons and cerebellum, while expression in the adult brain appeared to be restricted to cortex and medulla oblongata. CCDC88C encodes DAPLE (HkRP2), a Hook-related protein with a binding domain for the central Wnt signalling pathway protein Dishevelled. Targeted quantitative RT-PCR and expression profiling of 84 genes from the Wnt signalling pathway in peripheral blood from the index patient and her healthy mother revealed increased mRNA levels of CCDC88C indicating transcriptional upregulation. Due to loss of CCDC88C function β-catenin (CTNNB1) and the downstream target LEF1 showed increased mRNA levels in the patient, but many genes from the Wnt pathway and transcriptional target genes showed reduced expression, which might be explained by a complex negative feedback loop. We have thus identified a further essential component of the Wnt signalling pathway in human brain development.
    Molecular syndromology 09/2010; 1(3):99-112.
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    ABSTRACT: The authors observed a patient with a cryptic subtelomeric de novo balanced translocation 46,XY.ish t(11;20)(p15.4;q13.2) presenting with severe mental retardation, muscular hypotonia, seizures, bilateral sensorineural hearing loss, submucous cleft palate, persistent ductus Botalli, unilateral cystic kidney dysplasia and frequent infections. Fluorescence in situ hybridisation mapping and sequencing of the translocation breakpoints showed that no known genes are disrupted at 20q13.2 and that ST5 (suppression of tumorigenicity 5; MIM 140750) is disrupted on 11p15.4. By quantitative PCR from different human tissues, the authors found ST5 to be relatively evenly expressed in fetal tissues. ST5 expression was more pronounced in adult brain, kidney and muscle than in the corresponding fetal tissues, whereas expression in other tissues was generally lower than in the fetal tissue. Using RNA in situ hybridisation in mouse, the authors found that St5 is expressed in the frontal cortex during embryonic development. In adult mouse brain, expression of St5 was especially high in the hippocampal area and cerebellum. Hence, the authors suppose that ST5 plays an important role in central nervous system development probably due to disturbance of DENN-domain-mediated vesicle formation and neurotransmitter trafficking. Thus, these findings implicate ST5 in the aetiology of mental retardation, seizures and multiple congenital anomalies.
    Journal of Medical Genetics 10/2009; 47(2):91-8. · 5.70 Impact Factor
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    ABSTRACT: Noonan syndrome (NS) is a genetically heterogeneous disorder caused most commonly by activating mutations in PTPN11. We report a patient with hypotonia, developmental delay and clinical features suggestive of NS. High-resolution chromosome analysis was normal, and sequence analyses of PTPN11, SOS1, KRAS, BRAF, RAF1, MEK, and MEK2 were also normal. Array CGH revealed a single copy gain of 9 BAC clones at 12q24.11q24.21 (8.98 Mb in size), which encompassed the PTPN11 locus at 12q24.13 and was confirmed by FISH analysis. Shchelochkov et al. [Shchelochkov et al. (2008); Am J Med Genet Part A 146A:1042-1048] reported a similar case and speculated that such duplications might account for 15-30% of NS cases with no detectable mutation in NS genes. We screened more than 250 NS cases without mutation in known NS disease-causing genes by quantitative PCR, and none of these studies produced results in the duplicated range. We also explored the possibility that de novo changes affecting the untranslated region (UTR) of the PTPN11 transcript might represent an alternative event involved in SHP2 enhanced expression. DHPLC analysis and direct sequencing of the entire 3' UTR in 36 NS patients without mutation in known genes did not show any disease-associated variant. These findings indicate that duplications of PTPN11 represent an uncommon cause of NS, and functionally relevant variations within the 3'UTR of the gene do not appear to play a major role in NS. However, recurrent observations of NS in individuals with duplications involving the PTPN11 locus suggest that increased dosage of SHP2 may have dysregulating effects on intracellular signaling.
    American Journal of Medical Genetics Part A 09/2009; 149A(10):2122-8. · 2.30 Impact Factor
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    ABSTRACT: Psoriasis is a genetically complex, chronic inflammatory skin disease. The authors have previously identified a susceptibility locus on chromosome 19p13 (PSORS6). In a follow-up linkage disequilibrium (LD) study in an independent family based cohort, the authors found evidence for association to a newly discovered microsatellite at this locus (D19SPS21, p<5.3x10(-5)). An LD based association scan in 300 trios revealed association to several single, single nucleotide polymorphisms (SNPs) in one LD block. When the authors stratified this cohort for carrying the PSORS1 risk allele at the HLA-C locus, evidence for association became much stronger at single SNP and haplotype levels (p values between 1.0x10(-4) and 8.0x10(-4)). In a replication study of 1114 patients and 937 control individuals, evidence for association was also observed after stratification to the PSORS1 risk allele. In both study groups, logistic regression showed evidence for interaction between the risk alleles at PSORS1 and PSORS6. Best p values for rs12459358 in both study groups remained significant after correction for multiple testing. The associated LD block did not comprise any known genes. Interestingly, an adjacent gene, MUC16, coding for a large glycosylated protein expressed in epithelia and of unknown function, could be shown to be also expressed in tissues relevant for pathogenesis of psoriasis such as skin and thymus. Immunohistochemical analyses of skin revealed focal staining for MUC16 in suprabasal epidermal cells. Further functional studies are required to clarify its potential role in psoriasis and identify the causal variant(s) at this locus. The data establish PSORS6 as a confirmed psoriasis susceptibility locus showing interaction with PSORS1.
    Journal of Medical Genetics 07/2009; 46(11):736-44. · 5.70 Impact Factor
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    ABSTRACT: Neurofibromatosis-Noonan syndrome (NFNS), an entity which combines both features of Noonan syndrome (NS) and neurofibromatosis type 1 (NF1), was etiologically unresolved until recent reports demonstrated NF1 mutations in the majority of patients with NFNS. The phenotypic overlap was explained by the involvement of the Ras pathway in both disorders, and, accordingly, clustering of the NF1 mutations in the GTPase-activating protein (GAP) domain of neurofibromin was observed in individuals with NFNS. We report on an 18-month-old girl with typical findings suggestive of NS in combination with multiple café-au-lait spots and bilateral optic gliomas suggestive of NF1. The patient was found to carry a de novo PTPN11 mutation p.T2I as well as the maternally inherited NF1 mutation c.4661+1G>C. Her otherwise healthy mother and brother, who also had the NF1 mutation, showed few café-au-lait spots as the only sign of neurofibromatosis. Since our patient's unique NF1 mutation results in skipping of exon 27a and thus involves the same region, Gap-related domain, that had been shown to be associated with NFNS, her phenotype could have been misleadingly attributed to the NF1 mutation only. Contrarily, absence of both cutaneous neurofibromas and NS features in her relatives with the same NF1 mutation, suggests that the index patient's typical NFNS phenotype is caused by an additive effect of mutations in both NF1 and PTPN11. In contrast to previous findings, we speculate that absence of cutaneous neurofibromas is not solely associated with the recurrent 3-bp in-frame deletion in exon 17.
    American Journal of Medical Genetics Part A 06/2009; 149A(6):1263-7. · 2.30 Impact Factor

Publication Stats

1k Citations
271.07 Total Impact Points

Institutions

  • 2005–2014
    • Friedrich-Alexander Universität Erlangen-Nürnberg
      • Department of Paediatrics
      Erlangen, Bavaria, Germany
  • 2011
    • Chiang Mai University
      • Faculty of Dentistry
      Chiang Mai, Chiang Mai Province, Thailand
  • 2009
    • University of Zurich
      Zürich, Zurich, Switzerland
  • 2005–2008
    • Universitätsklinikum Erlangen
      • Institute of Human Genetics
      Erlangen, Bavaria, Germany
  • 2007
    • University of Leipzig
      • Institut für Veterinär-Pathologie
      Leipzig, Saxony, Germany