1/7. CF gene and cystic fibrosis transmembrane conductance regulator expression in autosomal dominant polycystic kidney disease.disease-modifying genes might participate in the significant intrafamilial variability of the renal phenotype in autosomal dominant polycystic kidney disease (ADPKD). Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) is a chloride channel that promotes intracystic fluid secretion, and thus cyst progression, in ADPKD. The hypothesis that mutations of the CF gene, which encodes CFTR, might be associated with a milder renal phenotype in ADPKD was tested. A series of 117 unrelated ADPKD probands and 136 unaffected control subjects were screened for the 12 most common mutations and the frequency of the alleles of the intron 8 polymorphic TN: locus of CF. The prevalence of CF mutations was not significantly different in the ADPKD (1.7%, n = 2) and control (3.7%, n = 5) groups. The CF mutation was DeltaF508 in all cases, except for one control subject (1717-1G A). The frequencies of the 5T, 7T, and 9T intron 8 alleles were also similar in the ADPKD and control groups. Two additional patients with ADPKD and the DeltaF508 mutation were detected in the families of the two probands with CF mutations. kidney volumes and renal function levels were similar for these four patients with ADPKD and DeltaF508 CFTR (heterozygous for three and homozygous for one) and for control patients with ADPKD collected in the University of colorado health Sciences Center database. The absence of a renal protective effect of the homozygous DeltaF508 mutation might be related to the lack of a renal phenotype in CF and the variable, tissue-specific expression of DeltaF508 CFTR. Immunohistochemical analysis of a kidney from the patient with ADPKD who was homozygous for the DeltaF508 mutation substantiated that hypothesis, because CFTR expression was detected in 75% of cysts (compared with <50% in control ADPKD kidneys) and at least partly in the apical membrane area of cyst-lining cells. These data do not exclude a potential protective role of some CFTR mutations in ADPKD but suggest that it might be related to the nature of the mutation and renal expression of the mutated CFTR.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/7. The genetic role in autosomal dominant polycystic kidney disease and nephrology clinical practice.The science of genetics is able to provide clinicians with early information on the inheritance of autosomal dominant polycystic kidney disease (ADPKD). It is also possible that nephrology clinicians will be able to promote early patient education and provide interventions to improve patient care. Mutations in PKD1 and PKD2 genes account for the majority of ADPKD. ADPKD is one of the most common genetic diseases in humans, crossing all ethnic populations worldwide with an occurrence of one in 500 to one in 1,000 (Igarashi and Somlo, 2002). Individuals with ADPKD, generally in their third and fourth decade, will clinically manifest the initial stages of renal insufficiency such as back pain, urinary tract infections, systemic hypertension and urolithiasis. Although the mechanisms of inheritance are well-described in many medical journals, disease onset, expression and severity are variable. The variable nature of ADPKD suggests that education is vital in helping ADPKD patients make informed decisions on their health and future.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/7. liver transplantation with preservation of the inferior vena cava in case of symptomatic adult polycystic disease.adult polycystic liver disease (APLD) is a rare disorder of the liver parenchyma, the treatment of which is still controversial. Conservative surgery may have a significant morbidity and is often ineffective in the long run. Liver replacement may be indicated in case of incapacitating hepatomegaly. patients (one male, five females) undergoing liver transplantation for symptomatic APLD is presented in this study. The particular nature of this series is the fact that successful transplantation was performed in all cases with preservation of the recipient's inferior vena cava and without use of veno-venous bypass despite massive hepatomegaly and previous extensive liver surgery (in three cases). There was minimal morbidity and no mortality. All patients have excellent quality of life with a median follow-up of 41 months (range: 12-58) as testified by a median Karnofsky score of 90% (range: 80-100%).- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/7. Autosomal dominant polycystic kidney disease in pregnancy complicated by twin gestation and severe preeclampsia: a case report.BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD), an autosomal dominant genetic disorder with a reported prevalence of 1 in 1,000, may be associated with hypertensive disease in pregnancy. The evaluation of a pregnant woman with an adult-onset genetic disorder is complex and involves counseling about inheritance, prenatal diagnosis and management of the current pregnancy. CASE: A 33-year-old woman presented for obstetric care with a history of hypertension and ADPKD for 6 years. The patient had secondary infertility, which was treated by in vitro fertilization. The case was complicated by twin gestation and superimposed severe preeclampsia, leading to preterm cesarean delivery at 26 weeks' estimated gestational age. CONCLUSION: Because of the heritable nature of ADPKD and the long-term risk of end-stage renal disease requiring dialysis and/or renal transplantation, the evaluation and counseling of women with ADPKD who are pregnant or considering pregnancy should include a discussion of the modes of inheritance, natural history, available prenatal diagnostic options, and pregnancy risks and management options. Specific counseling issues in this case include the genetic concepts of variable expression and penetrance and the medical management of chronic hypertension and preeclampsia.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/7. Identification of mutations in the duplicated region of the polycystic kidney disease 1 gene (PKD1) by a novel approach.mutation screening of the major autosomal dominant polycystic kidney disease gene (PKD1) has been complicated by the large transcript size (> 14 kb) and by reiteration of the genomic area encoding 75% of the protein on the same chromosome (the HG loci). The sequence similarity between the PKD1 and HG regions has precluded specific analysis of the duplicated region of PKD1, and consequently all previously described mutations map to the unique 3' region of PKD1. We have now developed a novel anchored reverse-transcription-PCR (RT-PCR) approach to specifically amplify duplicated regions of PKD1, employing one primer situated within the single-copy region and one within the reiterated area. This strategy has been incorporated in a mutation screen of 100 patients for more than half of the PKD1 exons (exons 22-46; 37% of the coding region), including 11 (exons 22-32) within the duplicated gene region, by use of the protein-truncation test (PTT). Sixty of these patients also were screened for missense changes, by use of the nonisotopic RNase cleavage assay (NIRCA), in exons 23-36. Eleven mutations have been identified, six within the duplicated region, and these consist of three stop mutations, three frameshifting deletions of a single nucleotide, two splicing defects, and three possible missense changes. Each mutation was detected in just one family (although one has been described elsewhere); no mutation hot spot was identified. The nature and distribution of mutations, plus the lack of a clear phenotype/genotype correlation, suggest that they may inactivate the molecule. RT-PCR/PTT proved to be a rapid and efficient method to detect PKD1 mutations (differentiating pathogenic changes from polymorphisms), and we recommend this procedure as a firstpass mutation screen in this disorder.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
6/7. Neonatal presentation of autosomal dominant polycystic kidney disease with a maternal history of tuberous sclerosis.BACKGROUND: Childhood presentation of polycystic kidney disease has been reported with tuberous sclerosis complex (TSC). Recently some such cases have been shown to be due to combined deletion of the PKD1 and TSC2 genes, which lie close together on chromosome 16. The phenomenon of anticipation, whereby disease presentation occurs at a progressively earlier age in each generation, has been suggested to occur in autosomal dominant polycystic kidney disease (ADPKD). We have carried out a genetic study of a family in which these issues became clinically relevant. Neonatal presentation of polycystic kidneys occurred in an individual with a maternal family history of epilepsy and features of TSC without renal cystic disease. methods: Detailed historical and clinical profiles were gathered for three generations of the maternal and paternal families. Both parents underwent renal ultrasound scanning. Genomic dna was obtained from affected and unaffected individuals from the maternal family and used for linkage analysis to gene loci for TSC. RESULTS: Renal cysts were not present in the mother by ultrasound. Linkage to TSC2 was found for members of the maternal family with clinical features of TSC. While a diagnosis of TSC was confirmed in her mother the child was found not to have inherited the disease-related allele. The father was found to have asymptomatic bilateral polycystic kidneys consistent with ADPKD. The presence of ADPKD in other paternal relatives could not be confirmed. CONCLUSIONS: The index case was found to have paternally inherited ADPKD with unusually early presentation. While at risk for concomitant maternal inheritance of TSC this diagnosis was ruled out by linkage analysis studies. The ability to clarify the true nature of a complex inherited condition greatly facilitates future management and counselling. The mechanisms underlying phenotypic heterogeneity in ADPKD remain to be clearly defined and are the subject of ongoing investigation.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/7. Germinal and somatic mutations in the PKD2 gene of renal cysts in autosomal dominant polycystic kidney disease.Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in one of three genes: PKD1 on chromosome 16 accounts for approximately 85% of cases whereas PKD2 on chromosome 4 accounts for approximately 15%. Mutations in the PKD3 gene are rare. All patients present with similar clinical phenotypes, and the cardinal symptom is the formation of fluid-filled cysts in the kidneys. Previous work has provided data supporting the notion that cysts in ADPKD1 are focal in nature and form after loss of function of polycystin 1. This became evident by demonstrating that the normal PKD1 allele was inactivated somatically by loss of heterozygosity or by mutagenesis in a subset of renal or liver cysts examined. We show in this report, for the first time, multiple novel somatic mutations within the PKD2 gene of epithelial cells, in both kidneys of an ADPKD2 patient. From a total of 21 cysts examined, seven (33%) had the same C insertion within the inherited wild-type allele. In two other cysts, a nonsense mutation and a splice site AG deletion had occurred in a PKD2 allele that could not be identified as the inherited wild-type or mutant. We suggest that the autosomal dominant form of ADPKD2 occurs by a cellular recessive mechanism, supporting a two-hit model for cyst formation.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |