PubMed Health⌕ Search

Biomedical subjects

Judith A Goodship

Publications and source records attributed to Judith A Goodship.

18 recordsLinked to original sources
PubMed2006

Sequencing EVC and EVC2 identifies mutations in two-thirds of Ellis-van Creveld syndrome patients.

Ellis-van Creveld syndrome (EvC) is caused by mutations in EVC and EVC2, genes in a divergent orientation separated by only 2.6 kb. We systematically sought mutations in both genes in a panel of 65 affected individuals to assess the proportion of cases resulting from mutations in each gene. We PCR amplified and sequenced the coding exons of both genes. We investigated mutations that could affect splicing by in vitro splicing assays and cDNA analysis. We have identified EVC mutations in 20 cases (31%); in all of these we have detected the mutation on each allele. We have identified EVC2 mutations in 25 cases (38%); in 22 of these we have isolated a mutation on each allele. The majority of the mutations introduce a premature termination codon. We sequenced the region between the two genes in 10 of the 20 cases in which we had not identified a mutation in either gene, revealing only one SNP that was not a common polymorphism. As we have not identified mutations in either gene in 20 cases (31%) it is possible that there is further genetic heterogeneity.

Alternative Splicing↗
PubMed2006

Disparate roles of ATR and ATM in immunoglobulin class switch recombination and somatic hypermutation.

Class switch recombination (CSR) and somatic hypermutation (SHM) are mechanistically related processes initiated by activation-induced cytidine deaminase. Here, we have studied the role of ataxia telangiectasia and Rad3-related protein (ATR) in CSR by analyzing the recombinational junctions, resulting from in vivo switching, in cells from patients with mutations in the ATR gene. The proportion of cells that have switched to immunoglobulin (Ig)A and IgG in the peripheral blood seems to be normal in ATR-deficient (ATRD) patients and the recombined S regions show a normal "blunt end-joining," but impaired end joining with partially complementary (1-3 bp) DNA ends. There was also an increased usage of microhomology at the mu-alpha switch junctions, but only up to 9 bp, suggesting that the end-joining pathway requiring longer microhomologies (> or =10 bp) may be ATR dependent. The SHM pattern in the Ig variable heavy chain genes is altered, with fewer mutations occurring at A and more mutations at T residues and thus a loss of strand bias in targeting A/T pairs within certain hotspots. These data suggest that the role of ATR is partially overlapping with that of ataxia telangiectasia-mutated protein, but that the former is also endowed with unique functional properties in the repair processes during CSR and SHM.

Ataxia Telangiectasia Mutated Proteins↗
PubMed2006

De novo gene conversion in the RCA gene cluster (1q32) causes mutations in complement factor H associated with atypical hemolytic uremic syndrome.

Many of the complement regulatory genes within the RCA cluster (1q32) have arisen through genomic duplication and the resulting high degree of sequence identity is likely to predispose to gene conversion events. The highest degree of identity is between the genes for factor H (CFH) and five factor H-related proteins--CFHL1, CFHL2, CFHL3, CFHL4, and CFHL5. CFH mutations are associated with atypical hemolytic uremic syndrome (aHUS). In the Newcastle cohort of 157 aHUS patients we have identified CFH mutations in 25 families or individuals. Eleven of these 25 independent mutations are either c.3226C>G,Q1076E; c.3572C>T,S1191L; c.3590T>C,V1197A or combined c.3572C>T,S1191L/c.3590T>C,V1197A. Sequence analysis shows that all four of these changes could have arisen as a result of gene conversion between CFH and CFHL1. Analysis of parental samples in two patients with S1191L/V1197A has shown that the changes are de novo thus providing conclusive evidence that gene conversion is the mutational mechanism in these two cases. To confirm that S1191L and V1197A are disease predisposing we examined their functional significance in three ways - analysis of the C3b/C3d binding characteristics of recombinant mutant S1191L/V1197A protein, heparin affinity chromatography and haemolytic assays of serum samples from aHUS patients carrying these changes. The results showed that these changes resulted in impaired C3b binding and a defective capacity to control complement activation on cellular surfaces. We, therefore, provide conclusive evidence that gene conversion is responsible for functionally significant CFH mutations in aHUS.

Animals↗
PubMed2006

Atypical haemolytic uraemic syndrome associated with a hybrid complement gene.

BACKGROUND: Sequence analysis of the regulators of complement activation (RCA) cluster of genes at chromosome position 1q32 shows evidence of several large genomic duplications. These duplications have resulted in a high degree of sequence identity between the gene for factor H (CFH) and the genes for the five factor H-related proteins (CFHL1-5; aliases CFHR1-5). CFH mutations have been described in association with atypical haemolytic uraemic syndrome (aHUS). The majority of the mutations are missense changes that cluster in the C-terminal region and impair the ability of factor H to regulate surface-bound C3b. Some have arisen as a result of gene conversion between CFH and CFHL1. In this study we tested the hypothesis that nonallelic homologous recombination between low-copy repeats in the RCA cluster could result in the formation of a hybrid CFH/CFHL1 gene that predisposes to the development of aHUS. METHODS AND FINDINGS: In a family with many cases of aHUS that segregate with the RCA cluster we used cDNA analysis, gene sequencing, and Southern blotting to show that affected individuals carry a heterozygous CFH/CFHL1 hybrid gene in which exons 1-21 are derived from CFH and exons 22/23 from CFHL1. This hybrid encodes a protein product identical to a functionally significant CFH mutant (c.3572C>T, S1191L and c.3590T>C, V1197A) that has been previously described in association with aHUS. CONCLUSIONS: CFH mutation screening is recommended in all aHUS patients prior to renal transplantation because of the high risk of disease recurrence post-transplant in those known to have a CFH mutation. Because of our finding it will be necessary to implement additional screening strategies that will detect a hybrid CFH/CFHL1 gene.

Adult↗
PubMed2005

Does complement factor B have a role in the pathogenesis of atypical HUS?

Atypical haemolytic uraemic syndrome (aHUS) is a disorder of complement dysregulation. Because complement factor B (fB) carries the catalytic site of the alternative pathway convertase we examined it as both a potential candidate gene and modifier in the pathogenesis of aHUS. No factor B gene (BF) mutations were found in 20 patients with aHUS. There was no statistical difference between controls and aHUS patients in either BF allele or haplotype frequency. In conclusion, in this small series of aHUS patients we found no evidence that fB has a major role in the pathogenesis of aHUS.

Case-Control Studies↗
PubMed2005

Mutations in complement factor I predispose to development of atypical hemolytic uremic syndrome.

Mutations in the plasma complement regulator factor H (CFH) and the transmembrane complement regulator membrane co-factor protein (MCP) have been shown to predispose to atypical hemolytic uremic syndrome (HUS). Both of these proteins act as co-factors for complement factor I (IF). IF is a highly specific serine protease that cleaves the alpha-chains of C3b and C4b and thus downregulates activation of both the classical and the alternative complement pathways. This study looked for IF mutations in a panel of 76 patients with HUS. Mutations were detected in two patients, both of whom had reduced serum IF levels. A heterozygous bp change, c.463 G>A, which results in a premature stop codon (W127X), was found in one, and in the other, a heterozygous single base pair deletion in exon 7 (del 922C) was detected. Both patients had a history of recurrent HUS after transplantation. This is in accordance with the high rate of recurrence in patients with CFH mutations. Patients who are reported to have mutations in MCP, by contrast, do not have recurrence after transplantation. As with CFH- and MCP-associated HUS, there was incomplete penetrance in the family of one of the affected individuals. This study provides further evidence that atypical HUS is a disease of complement dysregulation.

Adult↗
PubMed2005

Cilia and disease.

Cilia are classified according to their microtubule components as 9+2 (motile) and 9+0 (primary) cilia. Disruption of 9+2 cilia, which move mucus across respiratory epithelia, leads to rhinitis, sinusitis and bronchiectasis. Approximately half of the patients with primary ciliary dyskinesia (PCD) have situs inversus, providing a link between left-right asymmetry and cilia. 9+0 cilia at the embryonic node are also motile and involved in establishing left-right asymmetry. Most 9+0 cilia, however, act as antennae, sensing the external environment. Defective 9+0 cilia of principal cells of the nephron cause cystic diseases of the kidney. In the rods and cones of the retina, photoreceptor discs and visual pigments are synthesized in the inner segment and transported to the distal outer segment through a narrow 9+0 connecting cilium; defects in this process lead to retinitis pigmentosa. Although the function of primary cilia in some organs is being elucidated, in many other organs they have not been studied at all. It is probable that many more cilia-related disorders remain to be discovered.

Animals↗
PubMed2004

A perspective on inversin.

Over the past 5 years, there has been increasing evidence for the role of primary (9+0) cilia in renal physiology and in establishing the left-right axis. The cilia in the renal tract are immotile and thought to have a sensory function. Cilia at the murine embryonic node have a vortical movement that sets up a leftward flow. Inversin, the protein defective in the inv mouse and in patients with type-2 nephronophthisis, localizes to both renal and node primary cilia. However, we present evidence that it is also expressed before the node forms and that its subcellular localization in renal tubular cells is not confined to the cilia. Its role in both the pathway determining left-right axis and renal function remains to be elucidated.

Animals↗
PubMed2004

Lack of major involvement of human uroplakin genes in vesicoureteral reflux: implications for disease heterogeneity.

BACKGROUND: Primary vesicoureteral reflux (VUR) is a hereditary disorder characterized by the retrograde flow of urine into the ureters and kidneys. It affects about 1% of the young children and is thus one of the most common hereditary diseases. Its associated nephropathy is an important cause of end-stage renal failure in children and adults. Recent studies indicate that genetic ablation of mouse uroplakin (UP) III gene, which encodes a 47 kD urothelial-specific integral membrane protein forming urothelial plaques, causes VUR and hydronephrosis. METHODS: To begin to determine whether mutations in UP genes might play a role in human VUR, we genotyped all four UP genes in 76 patients with radiologically proven primary VUR by polymerase chain reaction (PCR) amplification and sequencing of all their exons plus 50 to 150 bp of flanking intronic sequences. RESULTS: Eighteen single nucleotide polymorphisms (SNPs) were identified, seven of which were missense, with no truncation or frame shift mutations. Since healthy relatives of the VUR probands are not reliable negative controls for VUR, we used a population of 90 race-matched, healthy individuals, unrelated to the VUR patients, as controls to perform an association study. Most of the SNPs were not found to be significantly associated with VUR. However, SNP1 of UP Ia gene affecting a C to T conversion and an Ala7Val change, and SNP7 of UP III affecting a C to G conversion and a Pro154Ala change, were marginally associated with VUR (both P= 0.08). Studies of additional cases yielded a second set of data that, in combination with the first set, confirmed a weak association of UP III SNP7 in VUR (P= 0.036 adjusted for both subsets of cases vs. controls). CONCLUSION: Such a weak association and the lack of families with simple dominant Mendelian inheritance suggest that missense changes of uroplakin genes cannot play a dominant role in causing VUR in humans, although they may be weak risk factors contributing to a complex polygenic disease. The fact that no truncation or frame shift mutations have been found in any of the VUR patients, coupled with our recent finding that some breeding pairs of UP III knockout mice yield litters that show not only VUR, but also severe hydronephrosis and neonatal death, raises the possibility that major uroplakin mutations could be embryonically or postnatally lethal in humans.

Alanine↗
PubMed2003

Mutations in human complement regulator, membrane cofactor protein (CD46), predispose to development of familial hemolytic uremic syndrome.

Membrane cofactor protein (MCP; CD46) is a widely expressed transmembrane complement regulator. Like factor H it inhibits complement activation by regulating C3b deposition on targets. Factor H mutations occur in 10-20% of patients with hemolytic uremic syndrome (HUS). We hypothesized that MCP mutations could predispose to HUS, and we sequenced MCP coding exons in affected individuals from 30 families. MCP mutations were detected in affected individuals of three families: a deletion of two amino acids (D237/S238) in family 1 (heterozygous) and a substitution, S206P, in families 2 (heterozygous) and 3 (homozygous). We evaluated protein expression and function in peripheral blood mononuclear cells from these individuals. An individual with the D237/S238 deletion had reduced MCP levels and approximately 50% C3b binding compared with normal controls. Individuals with the S206P change expressed normal quantities of protein, but demonstrated approximately 50% reduction in C3b binding in heterozygotes and complete lack of C3b binding in homozygotes. MCP expression and function was evaluated in transfectants reproducing these mutations. The deletion mutant was retained intracellularly. S206P protein was expressed on the cell surface but had a reduced ability to prevent complement activation, consistent with its reduced C3b binding and cofactor activity. This study presents further evidence that complement dysregulation predisposes to development of thrombotic microangiopathy and that screening patients for such defects could provide informed treatment strategies.

Amino Acid Substitution↗
PubMed2003

Successful (?) therapy of hemolytic-uremic syndrome with factor H abnormality.

We report a patient with continuously recurring hemolytic-uremic syndrome due to factor H deficiency. First at the age of 3 months he showed signs of hemolytic anemia, thrombocytopenia and renal insufficiency, often recurring concomitantly with respiratory tract infections, despite weekly to twice weekly plasma substitution (20 ml/kg body weight). Now at the age of 3.5 years glomerular filtration rate is approximately 50 ml/min/1.73 m(2) and psychomotoric development is normal. Since factor H is mainly synthesized in the liver, hepatic transplantation has been proposed as curative treatment. Before justification of liver transplantation as the ultimate treatment for these patients, an international registry should be developed to optimize and standardize therapeutic alternatives.

Child, Preschool↗
PubMed2003

A splicing mutation affecting expression of ataxia-telangiectasia and Rad3-related protein (ATR) results in Seckel syndrome.

Seckel syndrome (OMIM 210600) is an autosomal recessive disorder characterized by intrauterine growth retardation, dwarfism, microcephaly and mental retardation. Clinically, Seckel syndrome shares features in common with disorders involving impaired DNA-damage responses, such as Nijmegen breakage syndrome (OMIM 251260) and LIG4 syndrome (OMIM 606593). We previously mapped a locus associated with Seckel syndrome to chromosome 3q22.1-q24 in two consanguineous Pakistani families. Further marker analysis in the families, including a recently born unaffected child with a recombination in the critical region, narrowed the region to an interval of 5 Mbp between markers D3S1316 and D3S1557 (145.29 Mbp and 150.37 Mbp). The gene encoding ataxia-telangiectasia and Rad3-related protein (ATR) maps to this region. A fibroblast cell line derived from an affected individual displays a defective DNA damage response caused by impaired ATR function. We identified a synonymous mutation in affected individuals that alters ATR splicing. The mutation confers a phenotype including marked microcephaly (head circumference 12 s.d. below the mean) and dwarfism (5 s.d. below the mean). Our analysis shows that UV-induced ATR activation can occur in non-replicating cells following processing by nucleotide excision repair.

Ataxia Telangiectasia Mutated Proteins↗
PubMed2003

Mutations in two nonhomologous genes in a head-to-head configuration cause Ellis-van Creveld syndrome.

Ellis-van Creveld syndrome (EvC) is an autosomal recessive skeletal dysplasia. Elsewhere, we described mutations in EVC in patients with this condition (Ruiz-Perez et al. 2000). We now report that mutations in EVC2 also cause EvC. These two genes lie in a head-to-head configuration that is conserved from fish to man. Affected individuals with mutations in EVC and EVC2 have the typical spectrum of features and are phenotypically indistinguishable.

Amino Acid Substitution↗
PubMed2003

Mutations in INVS encoding inversin cause nephronophthisis type 2, linking renal cystic disease to the function of primary cilia and left-right axis determination.

Nephronophthisis (NPHP), an autosomal recessive cystic kidney disease, leads to chronic renal failure in children. The genes mutated in NPHP1 and NPHP4 have been identified, and a gene locus associated with infantile nephronophthisis (NPHP2) was mapped. The kidney phenotype of NPHP2 combines clinical features of NPHP and polycystic kidney disease (PKD). Here, we identify inversin (INVS) as the gene mutated in NPHP2 with and without situs inversus. We show molecular interaction of inversin with nephrocystin, the product of the gene mutated in NPHP1 and interaction of nephrocystin with beta-tubulin, a main component of primary cilia. We show that nephrocystin, inversin and beta-tubulin colocalize to primary cilia of renal tubular cells. Furthermore, we produce a PKD-like renal cystic phenotype and randomization of heart looping by knockdown of invs expression in zebrafish. The interaction and colocalization in cilia of inversin, nephrocystin and beta-tubulin connect pathogenetic aspects of NPHP to PKD, to primary cilia function and to left-right axis determination.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Expression analyses and interaction with the anaphase promoting complex protein Apc2 suggest a role for inversin in primary cilia and involvement in the cell cycle.

Homozygous inv mice lack a functional inversin protein and exhibit situs inversus plus severe cystic changes in the kidney and pancreas. Although the inversin sequence has provided few clues to its function, we and others have previously identified calmodulin as a binding partner. We now provide evidence that inversin interacts with the anaphase promoting complex protein Apc2. As expected of an Apc2 target, inversin possesses D-boxes and site-directed mutagenesis of the well-conserved D-box residues abrogates inversin-Apc2 interaction. An inversin-specific antibody reveals a dynamic expression pattern throughout the cell cycle and strong expression in the primary cilia of renal epithelium. Our data support a role for inversin in primary cilia and involvement in the cell cycle. Mutations of the proteins polaris, cystin and polycystin-2 which are expressed in renal epithelium primary cilia, lead to renal cystic changes. Aberrant cell proliferation is also involved in cyst development. The data reported here suggest that inversin may provide a link between these two mechanisms.

Amino Acid Motifs↗
PubMed2002

Solitary functioning kidney and diverse genital tract malformations associated with hepatocyte nuclear factor-1beta mutations.

BACKGROUND: Renal tract malformations are, on occasion, associated with uterine malformations. The transcription factor hepatocyte nuclear factor (HNF)-1beta is expressed from the earliest stages of development of the Wolffian duct, the mesonephros and metanephros, and the Müllerian ducts in the mouse. In adult mice HNF-1beta is expressed in the kidney tubules, collecting ducts, and in the oviducts and uterus in the female (Müllerian duct derivatives) and in the epididymis, vas deferens and seminal vesicles (Wolffian duct derivatives) in the male. HNF-1beta mutations have been reported in two families where affected members have renal abnormalities, female genital tract malformations and early-onset diabetes. Renal and uterine abnormalities have not been described in families without early-onset diabetes. METHODS: We sequenced the HNF-1beta gene in nine subjects with renal abnormalities and a personal or family history of female genital tract malformations, but no history of diabetes. RESULTS: Two families were identified with novel HNF-1beta mutations: a missense mutation in exon 2 with conversion of serine to proline at codon 151 (S151P) and a frameshift mutation in exon 3 with a 1 base pair deletion at codon 243 (Q243fsdelC). The S151P mutation proband has cystic kidneys and uterus didelphys. Her affected second son has renal cysts and hypospadias. The Q243fsdelC proband has a single functioning kidney and her two children have renal dysplasia. Histology in one child shows cystic dysplasia with a lack of glomeruli. The proband's sister is a mutation carrier and has a bicornuate uterus. Diabetes is not a feature in either family. CONCLUSIONS: This study confirms an association between HNF-1beta mutations and renal and Müllerian anomalies. The hypospadias may be coincidental. This study describes the first HNF-1beta mutations that are associated with a single functioning kidney and the absence of diabetes. This study further reinforces the variability of the renal and non-renal phenotypes associated with HNF-1beta mutations.

Adult↗
PubMed2002

The genetics and pathogenesis of haemolytic uraemic syndrome and thrombotic thrombocytopenic purpura.

PURPOSE OF REVIEW: In recent years there has been a substantial increase in the understanding of the genetics and pathogenesis of haemolytic uraemic syndrome and thrombotic thrombocytopenic purpura. RECENT FINDINGS: In diarrhoeal associated haemolytic uraemic syndrome it has been established that the virulence of Escherichia coli O157 is related to intimin adhesion and the transport of verocytotoxin on polymorphonuclear cells. It has been shown that early changes in the coagulation pathway predate the onset of diarrhoeal haemolytic uraemic syndrome. Mutations in factor H, a fluid-phase regulator of the alternative complement pathway, have been identified in 10-20% of patients with both familial and sporadic (non-diarrhoeal-associated) haemolytic uraemic syndrome. The mutations mainly cluster in the C terminal part of factor H, a region that is important for both binding to C3b and also polyanionic structures on cell surfaces. The identification of antibodies against a plasma metalloproteinase responsible for cleaving ultralarge von Willebrand factor multimers in thrombotic thrombocytopenic purpura has been followed by the elucidation of the identity of the proteinase. It has been shown to be a member of the ADAMTS family, and mutations have been identified in the gene in families with inherited thrombotic thrombocytopenic purpura. SUMMARY: The molecular pathogenesis of haemolytic uraemic syndrome and thrombotic thrombocytopenic purpura is an exciting and rapidly evolving field. These recent advances will lead to logical, targetted changes in the management of these conditions.

Diarrhea↗