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J Kere

Publications and source records attributed to J Kere.

At least 55 records · Page 3Linked to original sources
PubMed2001

Cystic fibrosis gene mutations deltaF508 and 394delTT in patients with chronic sinusitis in Finland.

Previous studies have shown that cystic fibrosis (CF) gene mutations are linked to several severe chronic infections. Chronic sinusitis is one condition that may well be influenced by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. We studied two prevalent CF mutations (AF508 and 394delTT) in a population with a low incidence of CF. The carrier frequency of the CF mutations in the Finnish population is approximately 1 in 80. We examined DNA specimens from 127 chronic sinusitis patients and found one patient who was heterozygous for 394delTT gene mutation. None of the DNA specimens had any AF508 mutation. This study shows that in a population with a low incidence of CF there was no abnormal carrier distribution of the two most common CF gene mutations in a group of chronic sinusitis patients. Routine screening of sinusitis patients for CF mutations provides no additional information on the etiology of chronic sinusitis.

Adult↗
PubMed2001

Autosomal dominant midfrequency hearing impairment.

At present, 48 different gene loci have been localised and nine gene mutations have been characterised for non-syndromic hearing impairment. We have identified a large five-generation family with mid-and high-frequency hearing impairment. Family members were considered to be affected only if they had bilateral sensorineural hearing loss below the 90th percentile of an age and sex-dependent control audiometric curve of ISO class B. The inheritance of hearing impairment was autosomal dominant. Of seven affected individuals, six were females and one was male. The hearing loss among affected family members was bilateral, sensorineural and varies from mild to moderate. The type of audiogram was U-shaped. Genetic linkage studies are in progress and our preliminary data show exclusion in chromosome 6, chromosome 11 and chromosome 19 in already known loci for midfrequency hearing impairment. This means, we are mapping a novel locus for autosomal dominant midfrequency hearing impairment.

Audiometry, Pure-Tone↗
PubMed2001

Distinct outcomes of chloride diarrhoea in two siblings with identical genetic background of the disease: implications for early diagnosis and treatment.

BACKGROUND: Congenital chloride diarrhoea (CLD, OMIM 214700) is a serious inherited defect of intestinal electrolyte absorption transmitted in an autosomal recessive fashion. The major clinical manifestation is diarrhoea with high chloride content which can be balanced by substitution. The molecular pathology involves an epithelial Cl(-)/HCO(3)(-) exchanger protein, encoded by the solute carrier family 26, member 3 gene (SLC26A3), previously known as CLD or DRA (downregulated in adenomas). To date, almost 30 different mutations in the SLC26A3 gene have been identified throughout the world. No clear genotype-phenotype correlation has been established. PATIENTS/METHODS: Two siblings presenting with CLD were studied for disease history, supplementation, or other treatments, and for mutations in the SLC26A3 gene. RESULTS: Mutation analysis revealed a homozygous I544N mutation in both patients. However, despite the uniform genetic background of CLD in this family, the clinical picture and outcome of the disease were remarkably different between siblings. The older sibling had a late diagnosis and chronic course of the disease whereas the younger one, who was diagnosed soon after birth and immediately received supplementation therapy, grows and develops normally. CONCLUSION: Time of diagnosis, substitution therapy, compliance, and compensatory mechanisms are more important modulators of the clinical picture of CLD than the type of mutation in the SLC26A3 gene.

Chloride Channels↗
PubMed2001

A dominant gene for developmental dyslexia on chromosome 3.

Developmental dyslexia is a neurofunctional disorder characterised by an unexpected difficulty in learning to read and write despite adequate intelligence, motivation, and education. Previous studies have suggested mostly quantitative susceptibility loci for dyslexia on chromosomes 1, 2, 6, and 15, but no genes have been identified yet. We studied a large pedigree, ascertained from 140 families considered, segregating pronounced dyslexia in an autosomal dominant fashion. Affected status and the subtype of dyslexia were determined by neuropsychological tests. A genome scan with 320 markers showed a novel dominant locus linked to dyslexia in the pericentromeric region of chromosome 3 with a multipoint lod score of 3.84. Nineteen out of 21 affected pedigree members shared this region identical by descent (corrected p<0.001). Previously implicated genomic regions showed no evidence for linkage. Sequencing of two positional candidate genes, 5HT1F and DRD3, did not support their role in dyslexia. The new locus on chromosome 3 is associated with deficits in all three essential components involved in the reading process, namely phonological awareness, rapid naming, and verbal short term memory.

Adolescent↗
PubMed2001

Human population genetics: lessons from Finland.

A population of about 5 million at the northern corner of Europe is unlikely to arouse the attention of the human genetics community, unless it offers something useful for others to learn. A combination of coincidences has finally made this population one that, out of proportion for its size, has by example shaped research in human disease genetics. This chapter summarizes advances made in medical genetics that are based on research facilitated by Finland's population structure. The annotation of the human genome for its polymorphism and involvement in disease is not over; it is, therefore, of interest to assess whether genetic studies in populations such as the Finnish might help in the remaining tasks.

Finland↗
PubMed2001

Concomitant DNA copy number amplification at 17q and 22q in dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans (DFSP) is a tumor of low or intermediate malignant potential with a tendency for recurrence, but low rate of metastasis. The tumorigenesis of DFSP has recently been shown to be associated with the fusion of the collagen type I alpha 1 (COL1A1) and platelet-derived growth factor B-chain (PDGFB) genes, often as a consequence of translocation t(17;22)(q22;q13). Cytogenetically, DFSP is often characterized by supernumerary ring chromosomes containing material from chromosomes 17 and 22. A subset of DFSPs undergo fibrosarcomatous transformation de novo or upon recurrence, and contain components indistinguishable from fibrosarcoma (FS-DFSP). The fibrosarcomatous transformation appears to carry an increased risk for recurrence and metastasis, and is considered to represent tumor progression. The molecular cytogenetic events contributing to tumor progression are unknown. We used comparative genomic hybridization to analyze DNA copy number changes in 11 cases of typical DFSP and 10 cases of FS-DFSP. All cases in both groups were found to exhibit a gain or high-level amplification on chromosome 17q and the majority also on 22q. This finding is in line with previous studies, and suggests further that not only the COL1A1/PDGFB fusion gene formation but also the role of DNA copy number gains in the 17q and 22q regions is crucial per se in the pathogenesis of DFSP. Even though FS-DFSPs displayed a trend toward increase in the number of DNA copy number changes, the difference was not statistically significant, which indicates that mechanisms other than copy number changes are important in the transformation process of DFSP.

Adolescent↗
PubMed2001

SLC26A2 (diastrophic dysplasia sulfate transporter) is expressed in developing and mature cartilage but also in other tissues and cell types.

Mutated alleles of the SLC26A2 (diastrophic dysplasia sulfate transporter or DTDST) gene cause each of the four recessive chondrodysplasias, i.e., diastrophic dysplasia (DTD), multiple epiphyseal dysplasia (MED), atelosteogenesis Type II (AO2), and achondrogenesis Type IB (ACG1B). SLC26A2 acts as an Na(+)-independent sulfate/chloride antiporter and belongs to the SLC26 anion transporter gene family, currently consisting of six homologous human members. Although Northern analysis has indicated some expression in all tissues studied, the only tissue known to be affected by SLC26A2 mutations is cartilage. Abundant SLC26A2 expression has previously been detected in normal human colon by in situ hybridization. We have used in situ hybridization and immunohistochemistry to examine multiple normal tissues for the expression of human SLC26A2. As expected, a strong signal for SLC26A2 mRNA and protein immunostaining were detected in developing fetal hyaline cartilage, while bronchial cartilage showed mRNA expression in adult tissues. SLC26A2 expression could also be detected in eccrine sweat glands, in bronchial glands, and in placental villi. In addition, immunoreactivity for the SLC26A2 protein was observed in exocrine pancreas. Our results suggest a more limited expression pattern for SLC26A2 than that found by Northern analysis. However, SLC26A2 expression is also detected in tissues not affected in chondrodysplasias caused by SLC26A2 mutations.

Anion Transport Proteins↗
PubMed2001

PPP2R1B gene in chronic lymphocytic leukemias and mantle cell lymphomas.

Deletion of chromosome bands 11q22-q23 is one of the most common structural chromosome alterations in chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL). The PPP2R1B gene is located very close to the minimal common deletion region of 11q22-q23 in CLL and MCL. Recently, the PPP2R1B gene was found to be mutated in human lung and colon cancers. To evaluate the role of the PPP2R1B gene in the pathogenesis of CLL and MCL, we performed RT-PCR analysis and cDNA sequencing on 10 CLL RNA samples and SSCP analysis on 26 CLL and 37 MCL genomic DNA samples. A deletion of exon 3 was found in one CLL sample. No mutation was detected in the SSCP analysis. To exclude the possibility of large genomic deletions we performed Southern blotting analysis. One MCL sample showed abnormal bands. Our results do not suggest that the PPP2R1B gene has a major pathogenic role in CLL and MCL.

Base Sequence↗
PubMed2001

Familial systemic lupus erythematosus in Finland.

OBJECTIVE: To perform a cross sectional nation-wide clinical study of familial systemic lupus erythematosus (SLE) in Finland. METHODS: We sought to identify all Finnish families in which at least 2 members satisfied the classification criteria for SLE. About 1,200 patients with SLE (80-85% of all patients attending Finnish hospitals) were contacted. Personal and/or phone interviews and examination of medical records were used to verify the diagnoses. A comparison of clinical characteristics was made between familial cases of SLE and matched sporadic controls. RESULTS: We identified 53 multiplex families with 113 SLE patients. Forty-six families had 2 affected members and 7 families had 3 affected members. There were 3 pairs of monozygotic female twins and one pair of dizygotic twins of the opposite sex concordant for SLE. Eleven (9.7%) of the 113 familial cases of SLE were male. No differences were found in the clinical presentation of SLE between familial and sporadic cases (sex, age at onset, major clinical manifestations, and common laboratory tests). The incidence of familial SLE was approximately 4-5%. CONCLUSION: Our study shows that familial and sporadic SLE are not different disease entities; this means that we can extrapolate the results of future genetic analyses in multiplex SLE families to all patients with SLE.

Adolescent↗
PubMed2000

A narrow segment of maternal uniparental disomy of chromosome 7q31-qter in Silver-Russell syndrome delimits a candidate gene region.

Maternal uniparental disomy of chromosome 7 (matUPD7), the inheritance of both chromosomes from only the mother, is observed in approximately 10% of patients with Silver-Russell syndrome (SRS). It has been suggested that at least one imprinted gene that regulates growth and development resides on human chromosome 7. To date, three imprinted genes-PEG1/MEST, gamma2-COP, and GRB10-have been identified on chromosome 7, but their role in the etiology of SRS remains uncertain. In a systematic screening with microsatellite markers, for matUPD7 cases among patients with SRS, we identified a patient who had a small segment of matUPD7 and biparental inheritance of the remainder of chromosome 7. Such a pattern may be explained by somatic recombination in the zygote. The matUPD7 segment at 7q31-qter extends for 35 Mb and includes the imprinted gene cluster of PEG1/MEST and gamma2-COP at 7q32. GRB10 at 7p11.2-p12 is located within a region of biparental inheritance. Although partial UPD has previously been reported for chromosomes 6, 11, 14, and 15, this is the first report of a patient with SRS who has segmental matUPD7. Our findings delimit a candidate imprinted region sufficient to cause SRS.

Abnormalities, Multiple↗
PubMed2000

Mapping of five new putative anion transporter genes in human and characterization of SLC26A6, a candidate gene for pancreatic anion exchanger.

A second distinct family of anion transporters, in addition to the classical SLC4 (or AE) family, has recently been delineated. Members of the SLC26 family are structurally well conserved and can mediate the electroneutral exchange of Cl(-) for HCO(-)(3) across the plasma membrane of mammalian cells like members of the SLC4 family. Three human transporter proteins have been functionally characterized: SLC26A2 (DTDST), SLC26A3 (CLD or DRA), and SLC26A4 (PDS) can transport with different specificities the chloride, iodine, bicarbonate, oxalate, and hydroxyl anions, whereas SLC26A5 (prestin) was suggested to act as the motor protein of the cochlear outer hair cell. We report the expansion of the SLC26 family with five new members in chromosomes 3, 6, 8, 12, and 17 and mapping of SLC26A1 to 4p16.3. We have characterized one of them, SLC26A6, in more detail. It maps to chromosome 3p21.3, encodes a predicted 738-amino-acid transmembrane protein, and is most abundantly expressed in the kidney and pancreas. Pancreatic ductal cell lines Capan-1 and Capan-2 express SLC26A6, and immunohistochemistry localizes SLC26A6 protein to the apical surface of pancreatic ductal cells, suggesting it as a candidate for a luminal anion exchanger. The functional characterization of the novel members of this tissue-specific gene family may provide new insights into anion transport physiology in different parts of the body.

Alternative Splicing↗
PubMed2000

A candidate gene for psoriasis near HLA-C, HCR (Pg8), is highly polymorphic with a disease-associated susceptibility allele.

A susceptibility gene for psoriasis, a chronic skin disorder, resides in chromosome 6p near the HLA-C locus. Sequencing of the region has allowed the identification of a new gene, HCR. We found that HCR is highly polymorphic with at least 12 coding variants. An association study of the new HCR polymorphisms and the previously suggested susceptibility alleles HLA-Cw*0602 and corneodesmosin allele 5 (CD*5) with psoriasis revealed a specific HCR variant associated with psoriasis susceptibility. However, the HLA-Cw*0602 allele was rarer in controls and associated with a stronger relative risk. Association analysis did not support CD*5 as a psoriasis susceptibility allele in our sample of patients (n = 100) and population-matched controls (n = 93) from an isolated population. We found HCR to be overexpressed in keratinocytes of psoriatic lesions compared with paired samples of healthy skin. Our results suggest a potential role for HCR in the pathogenesis of psoriasis.

Adolescent↗
PubMed2000

Data mining applied to linkage disequilibrium mapping.

We introduce a new method for linkage disequilibrium mapping: haplotype pattern mining (HPM). The method, inspired by data mining methods, is based on discovery of recurrent patterns. We define a class of useful haplotype patterns in genetic case-control data and use the algorithm for finding disease-associated haplotypes. The haplotypes are ordered by their strength of association with the phenotype, and all haplotypes exceeding a given threshold level are used for prediction of disease susceptibility-gene location. The method is model-free, in the sense that it does not require (and is unable to utilize) any assumptions about the inheritance model of the disease. The statistical model is nonparametric. The haplotypes are allowed to contain gaps, which improves the method's robustness to mutations and to missing and erroneous data. Experimental studies with simulated microsatellite and SNP data show that the method has good localization power in data sets with large degrees of phenocopies and with lots of missing and erroneous data. The power of HPM is roughly identical for marker maps at a density of 3 single-nucleotide polymorphisms/cM or 1 microsatellite/cM. The capacity to handle high proportions of phenocopies makes the method promising for complex disease mapping. An example of correct disease susceptibility-gene localization with HPM is given with real marker data from families from the United Kingdom affected by type 1 diabetes. The method is extendable to include environmental covariates or phenotype measurements or to find several genes simultaneously.

Adolescent↗
PubMed2000

Clinical findings in mosaic carriers of hypohidrotic ectodermal dysplasia.

BACKGROUND: Hypohidrotic ectodermal dysplasia (HED) is a severe developmental disorder in which nonallelic genetic heterogeneity has been demonstrated. Even though X-linked and autosomal recessive forms are phenotypically similar, identification of the way of transmission is mandatory to give reliable genetic counseling to the family and to address molecular studies. Complete examination of relatives of patients with HED and identification of carriers of partial forms of the disorder in their families is the key to clarifying intrafamilial genetic transmission. OBSERVATIONS: Seven patients diagnosed as having HED and their first-degree relatives were carefully examined and tested with starch-iodine. Useful signs for identifying possible carriers of and postzygotic mosaics for X-linked HED and for finding distinctive features between the X-linked and the autosomal recessive forms of the disorder were recorded. Of these, the most striking finding was the clinical evidence of the distribution of normal and abnormal skin along Blaschko lines in heterozygous and postzygotic mutation carriers of X-linked HED. Six heterozygous female carriers of X-linked HED, 2 males with postzygotic mutations for X-linked HED, and 1 female with autosomal recessive HED were clinically identified. At the end, 6 families had a diagnosis of X-linked HED, while 1 had a diagnosis ofautosomal recessive HED. Clinical data, family history, and starch-iodine test results were never in conflict in the 7 families. CONCLUSIONS: Careful clinical examination is the best way to detect heterozygous carriers and postzygotic mutation of X-linked HED. Heterozygous parents of patients with autosomal recessive HED show no features of the disorder. The starch-iodine test is not superior to a clinical examination in heterozygous carrier detection but may play a confirmative role and be of help in differentiating X-linked and autosomal recessive HED in isolated patients.

Adult↗
PubMed2000

The congenital chloride diarrhea gene is expressed in seminal vesicle, sweat gland, inflammatory colon epithelium, and in some dysplastic colon cells.

Congenital chloride diarrhea (CLD) is an autosomal recessive disorder of intestinal electrolyte transportation caused by mutations in the anion transporter protein encoded by the down-regulated in adenoma (DRA), or CLD, gene. In this study, in situ hybridization and immunohistochemistry were performed to investigate the expression of CLD in extraintestinal normal epithelia and in intestinal inflammatory and neoplastic epithelia. The expression of the closely related anion transporter diastrophic dysplasia sulfate transporter, DTDST, was also examined and compared with that of CLD in colon. The only extraintestinal tissues showing CLD expression were eccrine sweat glands and seminal vesicles. In inflammatory bowel disease and ischemic colitis, expression of CLD mRNA in colon epithelium was similar to histologically normal colon epithelium, but the protein was found deeper in crypts, including proliferative epithelial cells. In intestinal tumors, the expression pattern of CLD was dependent on the differentiation status of the tissue studied: epithelial polyps with no or minor dysplasia showed abundant expression, whereas adenocarcinomas were negative. The DTDST gene was abundantly expressed in the upper crypt epithelium of colonic mucosa.

Chlorides↗
PubMed2000

Inherited disorders of ion transport in the intestine.

Within the past year, it has been established that the gene mutated in the human disorder congenital chloride diarrhea encodes a major Cl-/HCO3- exchanger at the apical membrane of gut epithelial cells. A major apical Na+/H+ exchanger has also been identified. New insight into metal ion absorption has been gained, and several new transporters without cognate diseases have been cloned.

Animals↗