ABSTRACT
BACKGROUND: Somatic mutations affecting components of the Ras-MAPK pathway are a common feature of cancer, whereas germline Ras pathway mutations cause developmental disorders including Noonan, Costello, and cardio-facio-cutaneous syndromes. These 'RASopathies' also represent cancer-prone syndromes, but the quantitative cancer risks remain unknown. METHODS: We investigated the occurrence of childhood cancer including benign and malignant tumours of the central nervous system in a group of 735 individuals with germline mutations in Ras signalling pathway genes by matching their information with the German Childhood Cancer Registry. RESULTS: We observed 12 cases of cancer in the entire RASopathy cohort vs 1.12 expected (based on German population-based incidence rates). This corresponds to a 10.5-fold increased risk of all childhood cancers combined (standardised incidence ratio (SIR)=10.5, 95% confidence interval=5.4-18.3). The specific cancers included juvenile myelomonocytic leukaemia=4; brain tumour=3; acute lymphoblastic leukaemia=2; rhabdomyosarcoma=2; and neuroblastoma=1. The childhood cancer SIR in Noonan syndrome patients was 8.1, whereas that for Costello syndrome patients was 42.4. CONCLUSIONS: These data comprise the first quantitative evidence documenting that the germline mutations in Ras signalling pathway genes are associated with increased risks of both childhood leukaemia and solid tumours.
Subject(s)
Costello Syndrome/genetics , Ectodermal Dysplasia/genetics , Failure to Thrive/genetics , Heart Defects, Congenital/genetics , Neoplasms/epidemiology , Noonan Syndrome/genetics , ras Proteins/genetics , Adolescent , Child , Child, Preschool , Costello Syndrome/pathology , Ectodermal Dysplasia/pathology , Facies , Failure to Thrive/pathology , Female , Germ-Line Mutation , Germany/epidemiology , Heart Defects, Congenital/pathology , Humans , Infant , Male , Neoplasms/etiology , Neoplasms/pathology , Noonan Syndrome/pathology , Registries , Risk Factors , Signal TransductionSubject(s)
DNA Mutational Analysis , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/genetics , Protein Serine-Threonine Kinases/genetics , Cooperative Behavior , Diabetes Mellitus, Type 1/diagnosis , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/physiopathology , Diabetes Mellitus, Type 2/diet therapy , Diabetes Mellitus, Type 2/physiopathology , Diabetes, Gestational/diagnosis , Diabetes, Gestational/genetics , Diabetes, Gestational/physiopathology , Female , Follow-Up Studies , Genetic Carrier Screening , Genetic Testing , Germinal Center Kinases , Glucose Tolerance Test , Glycated Hemoglobin/metabolism , Humans , Infant , Infant, Newborn , Insulin-Secreting Cells/physiology , Interdisciplinary Communication , Long-Term Care , Male , Pedigree , Phenotype , PregnancyABSTRACT
Hereditary periodic fever syndromes (HPFSs) are a subset of human autoinflammatory diseases characterized by periodic episodes of fever and signs of inflammation with or without involvement of inner organs. In this paper, we report phenotypic features of an index patient and affected family members that present a previously not described mutation type in the TNFRSF1A gene. The phenotype of a HPFS of affected family members was shown to be associated with two monoallelic mutations in TNFRSF1A. Primarily, the index patient was clinically diagnosed as being affected by familial Mediterranean fever (FMF). However, with molecular genetic analyses, it could be shown that the patient was in fact affected by tumor necrosis factor receptor-associated periodic syndrome, which requires a different therapy when compared with FMF. Thus, molecular genetic analyses of currently known disease loci enable the most precise diagnosis presently available and are consequently the basis for the most effective therapeutic intervention.
Subject(s)
Genetic Predisposition to Disease/genetics , Hereditary Autoinflammatory Diseases/genetics , Hereditary Autoinflammatory Diseases/immunology , Mutation/genetics , Receptors, Tumor Necrosis Factor, Type I/genetics , Abdominal Pain , Adult , Age of Onset , Alleles , DNA Mutational Analysis , Female , Genetic Markers/genetics , Genetic Testing , Genotype , Hematuria/etiology , Hereditary Autoinflammatory Diseases/physiopathology , Humans , Inheritance Patterns/genetics , Male , Pedigree , Peritonitis/etiologyABSTRACT
BACKGROUND: Mutations and deletions of the homeobox transcription factor gene SHOX are known to cause short stature. The authors have analysed SHOX enhancer regions in a large cohort of short stature patients to study the importance of regulatory regions in developmentally relevant genes like SHOX. METHODS: The authors tested for the presence of copy number variations in the pseudoautosomal region of the sex chromosomes in 735 individuals with idiopathic short stature and compared the results to 58 cases with Leri-Weill syndrome and 100 normal height controls, using fluorescence in situ hybridisation (FISH), single nucleotide polymorphism (SNP), microsatellites, and multiplex ligand dependent probe amplification (MLPA) analysis. RESULTS: A total of 31/735 (4.2%) microdeletions were identified in the pseudoautosomal region in patients with idiopathic short stature; eight of these microdeletions (8/31; 26%) involved only enhancer sequences residing a considerable distance away from the gene. In 58 Leri-Weill syndrome patients, a total of 29 microdeletions were identified; almost half of these (13/29; 45%) involve enhancer sequences and leave the SHOX gene intact. These deletions were absent in 100 control persons. CONCLUSION: The authors conclude that enhancer deletions in the SHOX gene region are a relatively frequent cause of growth failure in patients with idiopathic short stature and Leri-Weill syndrome. The data highlights the growing recognition that regulatory sequences are of crucial importance in the genome when diagnosing and understanding the aetiology of disease.
Subject(s)
Chromosomes, Human, X , Chromosomes, Human, Y , Gene Deletion , Growth Disorders/genetics , Homeodomain Proteins/genetics , Child , Child, Preschool , Chromosome Mapping , Cohort Studies , DNA/chemistry , DNA/genetics , Female , Gene Dosage , Humans , In Situ Hybridization, Fluorescence , Male , Microsatellite Repeats/genetics , Polymorphism, Single Nucleotide/genetics , Regulatory Sequences, Nucleic Acid , Short Stature Homeobox ProteinABSTRACT
Achondrogenesis type II (ACG2) is the most severe disorder that can be produced by dominant mutations in COL2A1. We report on four pregnancies of an apparently healthy, nonconsanguineous young couple. The father had scoliosis as a child, and has slight body disproportion with short trunk. The first child was born at 32 weeks and died neonatally. In the second pregnancy, short limbs and fetal hygroma were noted on ultrasound at 17 weeks' gestation. Similar findings were observed in the third fetus. Clinical, radiological, and histological evaluation of the fetuses after termination of the pregnancies showed findings consistent with ACG2. Molecular analysis of genomic DNA extracted from amniotic cells of the second and third fetuses revealed heterozygosity for a 10370G > T missense mutation (G346V) in the COL2A1 gene. This mutation was also found in the father, as a mosaic. The couple had a fourth pregnancy, and at 11 weeks fetal hydrops with a septated cystic hygroma were obvious. DNA from CVS demonstrated the same COL2A1 mutation.
Subject(s)
Collagen Type II/genetics , Genes, Dominant , Mosaicism , Mutation , Osteochondrodysplasias/genetics , Adult , Base Sequence , DNA Primers , Female , Humans , Infant, Newborn , Male , Pregnancy , Ultrasonography, PrenatalABSTRACT
In the differential diagnosis of thrombophilic disorders genotyping of prothrombin and factor V are nowadays performed as a routine analysis. In the following we describe the unusual results of the mutation screening using melting point analysis for two patients and the consecutive detection of the mutation C20209T by sequencing the corresponding gene fragments. The molecular result is discussed with special respect to the medical history, ethnic background and clinical findings of both patients.
Subject(s)
DNA Mutational Analysis/methods , Hot Temperature , Nucleic Acid Denaturation/genetics , Point Mutation , Prothrombin/genetics , Adult , Female , Humans , Male , Polymerase Chain Reaction/instrumentation , Sequence Analysis, DNA/methods , Thrombophilia/diagnosisABSTRACT
BACKGROUND: Gillespie syndrome is the phenotype partial aniridia, cerebellar ataxia and mental retardation. Further malformations can be associated, mainly females are affected. Inheritance and genetics of the syndrome are unknown. Autosomal dominant aniridia is an important differential diagnosis of fixed dilated pupils and is usually associated by mutations of the PAX6 gene. In 1998 the first report of a chromosomal abnormality presenting a de novo translocation t(X;11) (p22.32;p12) detected in a patient with Gillespie syndrome has been published. PATIENTS AND METHODS: A 8 year-old girl with Gillespie syndrome phenotype associated with congenital pulmonary stenosis and helix dysplasia is reported. Karyotyping as well as molecular biological investigations of the PAX6 gene were performed. RESULTS: The karyotype of the girl and her clinically inconspicuous mother showed no abnormalities, especially no de novo translocation of the chromosomes X and 11. PAX6 gene analysis of the affected girl presented no mutations. CONCLUSIONS: The combination of muscular hypotonia and fixed dilated pupils in infancy is suspicious of Gillespie syndrome. Congenital pulmonary stenosis and helix dysplasia can be associated. PAX6 gene analysis can be helpful to distinguish between autosomal dominant aniridia and Gillespie syndrome. To illucidate the underlying genetic defects karyotyping and the search for de novo translocations especially of chromosome X and 11 should be performed.
Subject(s)
Abnormalities, Multiple , Cerebellum/abnormalities , Eye Proteins/genetics , Homeodomain Proteins/genetics , Intellectual Disability , Iris/abnormalities , Abnormalities, Multiple/genetics , Cerebellum/pathology , Child , Chromosome Aberrations/genetics , Chromosome Disorders , Female , Humans , Iris/pathology , Karyotyping , Magnetic Resonance Imaging , PAX6 Transcription Factor , Paired Box Transcription Factors , Phenotype , Polymerase Chain Reaction , Repressor Proteins , Syndrome , Translocation, GeneticABSTRACT
By protein interaction screening using a radioactive LMO2 protein probe we have isolated a LIM domain binding protein. The gene shows high homology to independently isolated genes from mouse, Xenopus and Drosophila called Ldb1/Nli/Clim-2, Xldb1 and Chip, respectively. The human and mouse genes differ by only two amino acids, suggesting that the gene that we have isolated is the human homologue. Here we describe the genomic organization, alternative transcript forms and the chromosome mapping of the human gene LDB1 (alias NLI). The gene is spread over at least 12 kb and has 11 exons. Preceding the described ATG initiation site in the mouse a highly conserved region between mouse, chicken and human was detected with a second possible in frame initiation site coding for further 36 amino acids. An alternative splice site adding six nucleotides corresponding to the addition of two amino acids at the end of exon 10 was found. The gene was mapped to chromosome 10q24-->q25 by in situ hybridization, a region frequently deleted in many types of cancer. Fine mapping with a radiation hybrid panel localized the gene in the interval between the markers D10S603 and D10S540.
Subject(s)
Alternative Splicing/genetics , DNA-Binding Proteins/genetics , Exons/genetics , Introns/genetics , Physical Chromosome Mapping , RNA, Messenger/genetics , Xenopus Proteins , Adaptor Proteins, Signal Transducing , Amino Acid Sequence , Animals , Base Sequence , Brain/embryology , Brain/metabolism , Chromosomes, Human, Pair 10/genetics , Cloning, Molecular , Codon, Initiator/genetics , Conserved Sequence/genetics , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , Gene Expression Profiling , Genetic Markers/genetics , Humans , Hybrid Cells , In Situ Hybridization, Fluorescence , LIM Domain Proteins , Metalloproteins/metabolism , Molecular Sequence Data , Protein Binding , Proto-Oncogene Proteins , RNA, Messenger/analysis , Transcription Factors , Zinc FingersABSTRACT
Aniridia (AN) is a sight-threatening congenital ocular disorder characterized by iris hypoplasia, corneal pannus, foveal and optic nerve hypoplasia, cataract formation, and glaucoma. In two-thirds of the patients, AN is inherited in an autosomal dominant fashion with almost complete penetrance but variable expression. The remaining cases are sporadic. Aniridia has been shown to be associated with mutations in the PAX6 gene, located on chromosome 11p13, telomeric to the Wilms' tumor predisposition gene (WT1). This paper describes 14 mutations in the PAX6 gene in patients with AN. Among these 14 mutations, 10 have been unpublished until now. They result most probably in haploinsufficiency and consequently in a reduced protein level of functional PAX6 protein. The mutations reported here are scattered all over the gene, including the paired-box, the glycine-rich region, the homeobox, and the proline-serine-threonine (PST)-rich region.
Subject(s)
Aniridia/genetics , DNA-Binding Proteins/genetics , Eye Proteins/genetics , Homeodomain Proteins , Mutation , Transcription Factors/genetics , Adolescent , Adult , Amino Acid Sequence , Child , Child, Preschool , DNA Mutational Analysis , Female , Humans , Infant , Male , Middle Aged , Molecular Sequence Data , PAX6 Transcription Factor , Paired Box Transcription Factors , Polymerase Chain Reaction , Polymorphism, Single-Stranded Conformational , Repressor ProteinsABSTRACT
INTRODUCTION: Aniridia represents a congenital ocular disorder with partial or complete iris hypoplasia. The disorder is associated with poor vision, glaucoma, corneal and lenticular opacities, ectopia lentis due to abnormal zonula fibers, as well as optic nerve and macular abnormalities. Aniridia may present as either hereditary or sporadic cases. Some of the sporadic cases develop Wilms' tumor, frequently as part of the WAGR syndrome (Wilms' tumor, aniridia, genitourinary abnormalities and mental retardation). PAX6, a candidate gene located on chromosome 11p13, is often mutated in aniridia patients. The gene encodes a transcription regulatory protein. METHOD: Analysis of the PAX6 gene was done using PCR (polymerase chain reaction), SSCP (single strand conformation polymorphism) and DNA sequencing. RESULTS: In 13 of 20 aniridia patients a PAX6 gene mutation was found. CONCLUSION: The mutations result in a gene product with reduced function or a reduced PAX6 protein level. Molecular analysis of aniridia is also a valuable diagnostic tool for Wilms' tumor risk evaluation, as patients with proven PAX6 mutations--in contrast to cases with large deletions of the 11p13 region--are at no increased risk to develop Wilms' tumor.
Subject(s)
Aniridia/genetics , DNA-Binding Proteins/genetics , Homeodomain Proteins , Chromosomes, Human, Pair 11 , DNA Mutational Analysis , Eye Proteins , Genetic Predisposition to Disease/genetics , Humans , Kidney Neoplasms/genetics , PAX6 Transcription Factor , Paired Box Transcription Factors , Repressor Proteins , Syndrome , Wilms Tumor/geneticsABSTRACT
The WT1 gene, located on chromosome 11p13, is mutated in a low number of Wilms tumors (WTs). Germ-line mutations in the WT1 gene are found in patients with bilateral WT and/or associated genital tract malformations (GU). We have identified 19 hemizygous WT1 gene mutations/deletions in 64 patient samples. The histology of the tumors with mutations was stromal-predominant in 13, triphasic in 3, blastemal-predominant in 1, and unknown in 2 cases. Thirteen of 21 patients with stromal-predominant tumors had WT1 mutations and 10 of these were present in the germ line. Of the patients with germ-line alterations, six had GU and a unilateral tumor, two had a bilateral tumor and normal GU tracts, and two had a unilateral tumor and normal GU. Three mutations were tumor-specific and were found in patients with unilateral tumors without GU. These data demonstrate a correlation of WT1 mutations with stromal-predominant histology, suggesting that a germ-line mutation in WT1 predisposes to the development of tumors with this histology. Twelve mutations are nonsense mutations resulting in truncations at different positions in the WT1 protein and only two are missense mutations. Of the stromal-predominant tumors, 67% showed loss of heterozygosity, and in one tumor a different somatic mutation in addition to the germ-line mutation was identified. These data show that in a large proportion of a histopathologically distinct subset of WTs the classical two-hit inactivation model, with loss of a functional WT1 protein, is the underlying cause of tumor development.
Subject(s)
DNA-Binding Proteins/genetics , Genes, Tumor Suppressor , Genes, Wilms Tumor , Germ-Line Mutation , Transcription Factors/genetics , Wilms Tumor/genetics , Gene Expression Regulation, Neoplastic , Humans , WT1 Proteins , Wilms Tumor/physiopathologyABSTRACT
Resistance to thyroid hormone (RTH) is an inherited defect manifesting as variable tissue hyporesponsiveness to thyroid hormone, usually caused by mutations in the thyroid hormone receptor beta (TR beta) gene. Up to now 78 mutations in this gene have been identified, mostly clustered in two regions located in exon 9 and 10. We describe a new point mutation replacing the normal thymidine-1274 with a cytosine that results in the substitution of the normal leucine-330 with a serine (L330S) in the receptor protein. This mutation was identified in an 11-year-old boy who presented with symptoms and signs suggestive of both hyperthyroidism and hypothyroidism. Interestingly a mutation in the same codon (L330F) has been previously described in a patient who presented with stigmata suggestive of thyrotoxicosis.
Subject(s)
Point Mutation/physiology , Receptors, Thyroid Hormone/genetics , Thyroid Hormone Resistance Syndrome/genetics , Child , DNA/analysis , Exons , Humans , Leucine/metabolism , Male , Multigene Family , Pedigree , Point Mutation/genetics , Serine/metabolism , Thyroid Function TestsABSTRACT
Waardenburg syndrome (WS) is a form of autosomal dominant inherited deafness combined with specific congenital anomalies. WS types I and III are correlated with mutations in the PAX3 gene on chromosome 2q37. In this report we describe two mutations in the human PAX3 gene causing WS type I in two families. One mutation is an insertion in the paired box domain resulting in a protein termination within the paired box. The second mutation is a base pair substitution producing an arginine to cysteine amino acid change in the homeobox region.
Subject(s)
DNA-Binding Proteins/genetics , Transcription Factors , Waardenburg Syndrome/genetics , Base Sequence , Child , Child, Preschool , Female , Humans , Male , Molecular Sequence Data , Mutation , PAX3 Transcription Factor , Paired Box Transcription FactorsABSTRACT
A germline WT-1 point mutation is described in a patient with unilateral Wilms' tumor, nephritis and ambiguous external genitalia. The patient was diagnosed as a possible case of Denys Drash syndrome (DDS). Analysis of the WT-1 exons and intron borders revealed a G to C transversion in the +1 position of the splice donor consensus sequence in intron 6. Two transcripts of abnormal size were identified in tumor RNA. Sequencing of the altered WT-1 mRNA revealed that this point mutation leads to exon-skipping, resulting in transcripts either missing exon 6 or exons 5 and 6. The normally occurring alternative splicing of exon 5 in the WT-1 gene is not affected by this mutation. The reading frame is changed when either both exons 5 and 6 or exon 6 alone are missing and a stop codon follows immediately downstream in exon 7. Most mutations identified in DDS are missense mutations located in the zinc finger (ZF) region (exons 7, 8 and 9) but recently a patient with a germline mutation in exon 6 leading to premature chain termination was described. Therefore the site of the mutation in the WT-1 gene in this patient cannot exclude the possibility that he has DDS.
Subject(s)
DNA-Binding Proteins/genetics , Genitalia/abnormalities , Point Mutation , Wilms Tumor/genetics , Base Sequence , Chromosome Deletion , Chromosomes, Human, Pair 11 , Consensus Sequence , Exons , Genes, Tumor Suppressor , Heterozygote , Humans , Male , Molecular Sequence Data , Polymerase Chain Reaction , RNA Splicing , Syndrome , WT1 Proteins , Zinc FingersABSTRACT
A Wilms' tumor susceptibility gene (WT1) localized to 11p13 was recently isolated and shown to be altered in some sporadic Wilms' tumors. This gene encodes a DNA-binding protein with four zinc fingers (ZFs) in the carboxy-terminal region and a glutamine/proline (Gln/Pro)-rich domain near the 5' end. Two alternative splice sites were described, splice I in the Gln/Pro-rich domain (51 bp) and splice II between ZFs 3 and 4 (9 bp). Using RNA polymerase chain reaction (PCR) we show that Wilms' tumors contain all four possible transcripts, which are also identified in normal adult and embryonic kidney cells. The transcripts containing the 9-bp ZF insert were always predominant in tumors and normal cells. The presence of all four WT1 transcripts in tumors and expressing tissues suggests that each encoded protein isoform has an important role for the function of the WT1 gene.
Subject(s)
Genes, Wilms Tumor , Kidney Neoplasms/genetics , Wilms Tumor/genetics , Adult , Base Sequence , Gene Expression , Humans , Kidney/embryology , Molecular Sequence Data , Polymerase Chain Reaction , RNA SplicingABSTRACT
We have cloned three genes (amy1, amy2 and amy3) encoding alpha-amylase in the filamentous fungus Aspergillus oryzae. The established overall sequences have a very high degree of homology, showing divergences mainly in the 3'-untranslated regions. The positions and the sequences of the eight introns were found to be absolutely identical in the three genes. The sequence analysis of the 5'-regions revealed presumptive TATA, CAAT and GC boxes. Primer extension analysis was performed to determine the transcription start. We were able to detect mRNAs from amy1 and amy3 but not from amy2 with gene-specific oligonucleotide probes complementary to the 3'-noncoding regions.