Because autosomal dominant polycystic kidney disease (ADPKD) is one of the most common genetic abnormalities seen in today's medical practice, many internists will likely treat patients affected by this condition. Genetic abnormalities have been increasingly recognized, and the pathophysiology of the disease is beginning to be unraveled. Because of advances in imaging technology, surrogate markers for disease progression have allowed clinical studies of newer therapeutic agents to proceed. In the near future, therapies for this common genetic disease may be available to either prevent or stabilize the disease course for many affected individuals.
Humans ; *Polycystic Kidney, Autosomal Dominant/complications/diagnosis/genetics/therapy ; Prognosis

The primary cilium of renal epithelia acts as a transducer of extracellular stimuli. Polycystin (PC)1 is the protein encoded by the PKD1 gene that is responsible for the most common and severe form of autosomal dominant polycystic kidney disease (ADPKD). PC1 forms a complex with PC2 via their respective carboxy-terminal tails. Both proteins are expressed in the primary cilia. Mutations in either gene affect the normal architecture of renal tubules, giving rise to ADPKD. PC1 has been proposed as a receptor that modulates calcium signals via the PC2 channel protein. The effect of PC1 dosage has been described as the rate-limiting modulator of cystic disease. Reduced levels of PC1 or disruption of the balance in PC1/PC2 level can lead to the clinical features of ADPKD, without complete inactivation. Recent data show that ADPKD resulting from inactivation of polycystins can be markedly slowed if structurally intact cilia are also disrupted at the same time. Despite the fact that no single model or mechanism from these has been able to describe exclusively the pathogenesis of cystic kidney disease, these findings suggest the existence of a novel cilia-dependent, cyst-promoting pathway that is normally repressed by polycystin function. The results enable us to rethink our current understanding of genetics and cilia signaling pathways of ADPKD.
Calcium ; Cilia* ; Genetics ; Kidney Diseases, Cystic ; Polycystic Kidney, Autosomal Dominant* ; Transducers ; TRPP Cation Channels*

Adult polycystic kidney disease (APKD) is a severe autosomal dominant inheritable renal disease with high incidence. Because of the late-onset of the disease, patients might have transferred the disease gene to the next generation when diagnosis is made. Since its pathogenic molecular mechanism is still not completely clear and the shortage of effective medicines, the prevention and treatment of the disease is still not satisfactory. In the present article, the recent advances in the research on the pathogenesis, gene diagnosis and management of APKD are reviewed.
Aged ; Female ; Humans ; Male ; Middle Aged ; Polycystic Kidney, Autosomal Dominant ; genetics ; Research ; TRPP Cation Channels ; genetics

Renin-angiotensin system is considered important in the genesis of hypertension and development of end-stage renal disease (ESRD) in autosomal dominant polycystic kidney disease (ADPKD). The angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism has been associated with susceptibility to the development of some renal diseases. We investigated the association of ACE gene polymorphism with the progression to hypertension and ESRD in 108 patients with ADPKD. The ACE I/D polymorphism was amplified with the flanking primers by polymerase chain reaction. In patients genotyped for ACE gene polymorphism, the frequencies of DD (15+ACU-), ID (51+ACU-) and II (34+ACU-) genotypes were similar to those of the general population. Of the 108 patients, 64 (59+ACU-) developed hypertension and 24 (22+ACU-) reached ESRD at the time of study. The prevalence of hypertension was not significantly different among the three genotypes. The mean renal survival time was 53-6 yr in II genotype, 5510 yr in ID genotype and 529 yr in DD genotype which was not significantly different among them. Cumulative renal survival was not significantly different either. There was no association of ACE gene polymorphism with the prevalence of hypertension and renal survival in ADPKD. We suggest that ACE I/D polymorphism is not an important modifying gene in the progression of ADPKD.
Adult ; Aged ; Comparative Study ; Disease Progression ; Female ; Genetic Predisposition to Disease ; Genotype ; Human ; Hypertension, Renal/etiology ; Hypertension, Renal/epidemiology ; Kidney Failure, Chronic/etiology ; Kidney Failure, Chronic/epidemiology ; Korea/epidemiology ; Male ; Middle Age ; Peptidyl-Dipeptidase A/genetics+ACo- ; Polycystic Kidney, Autosomal Dominant/genetics+ACo- ; Polycystic Kidney, Autosomal Dominant/epidemiology ; Polycystic Kidney, Autosomal Dominant/enzymology ; Polycystic Kidney, Autosomal Dominant/complications ; Polymerase Chain Reaction ; Polymorphism (Genetics)+ACo- ; Prevalence

Renin-angiotensin system is considered important in the genesis of hypertension and development of end-stage renal disease (ESRD) in autosomal dominant polycystic kidney disease (ADPKD). The angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism has been associated with susceptibility to the development of some renal diseases. We investigated the association of ACE gene polymorphism with the progression to hypertension and ESRD in 108 patients with ADPKD. The ACE I/D polymorphism was amplified with the flanking primers by polymerase chain reaction. In patients genotyped for ACE gene polymorphism, the frequencies of DD (15+ACU-), ID (51+ACU-) and II (34+ACU-) genotypes were similar to those of the general population. Of the 108 patients, 64 (59+ACU-) developed hypertension and 24 (22+ACU-) reached ESRD at the time of study. The prevalence of hypertension was not significantly different among the three genotypes. The mean renal survival time was 53-6 yr in II genotype, 5510 yr in ID genotype and 529 yr in DD genotype which was not significantly different among them. Cumulative renal survival was not significantly different either. There was no association of ACE gene polymorphism with the prevalence of hypertension and renal survival in ADPKD. We suggest that ACE I/D polymorphism is not an important modifying gene in the progression of ADPKD.
Adult ; Aged ; Comparative Study ; Disease Progression ; Female ; Genetic Predisposition to Disease ; Genotype ; Human ; Hypertension, Renal/etiology ; Hypertension, Renal/epidemiology ; Kidney Failure, Chronic/etiology ; Kidney Failure, Chronic/epidemiology ; Korea/epidemiology ; Male ; Middle Age ; Peptidyl-Dipeptidase A/genetics+ACo- ; Polycystic Kidney, Autosomal Dominant/genetics+ACo- ; Polycystic Kidney, Autosomal Dominant/epidemiology ; Polycystic Kidney, Autosomal Dominant/enzymology ; Polycystic Kidney, Autosomal Dominant/complications ; Polymerase Chain Reaction ; Polymorphism (Genetics)+ACo- ; Prevalence

OBJECTIVETo use microsatellite DNA tightly linked to polycystic kidney disease gene 2 in the gene diagnosis of autosomal dominant polycystic kidney disease type 2.

METHODSMicrosatellite DNA of D4S1534, D4S1542, D4S1563,D4S2460 and D4S423 were amplified with PCR and the fragments of products were analyzed by capillary electrophoresis and Genescan and Genotyper software, and then gene diagnosis of the pedigrees was made by linkage analysis.

RESULTSThree families were found to be linked to PKD2 in 20 families. Two carriers of PKD2 mutation were revealed by linkage analysis.

CONCLUSIONGene diagnosis can be done for PKD2 mutation carriers prior to cytogenesis. Linkage analysis is a rapid, simple method for studying the heterogeneity of polycystic kidney disease and for diagnosing the disease at the molecular level.

Female ; Genetic Linkage ; Humans ; Male ; Microsatellite Repeats ; genetics ; Mutation ; Polycystic Kidney, Autosomal Dominant ; diagnosis ; genetics ; TRPP Cation Channels ; genetics

OBJECTIVE: To detect potential variants in eight Chinese pedigrees affected with autosomal dominant polycystic kidney disease (ADPKD) and provide prenatal diagnosis for two of them. METHODS: Whole exome sequencing and high-throughput sequencing were carried out to detect variants of PKD1 and PKD2 genes in the probands. Sanger sequencing was used to validate the variants, and their pathogenicity was predicted by searching the ADPKD and protein variation databases. RESULTS: Eight PKD1 variants were detected, which have included five nonsense mutations and three missense mutations. Among these, four nonsense variants (PKD1: c.7555C>T, c.7288C>T, c.4957C>T, c.11423G>A) were known to be pathogenic, whilst one missense variant (PKD1: c.2180T>G) was classified as likely pathogenic. Three novel variants were detected, which included c.6781G>T (p.Glu2261*), c.109T>G (p.Cys37Gly) and c.8495A>G (p.Asn2832Ser). Prenatal testing showed that the fetus of one family has carried the same mutation as the proband, while the fetus of another family did not. CONCLUSION PKD1 variants, including three novel variants, have been identified in the eight pedigrees affected with ADPKD. Based on these results, prenatal diagnosis and genetic counseling have been provided.
DNA Mutational Analysis/methods* ; Female ; Humans ; Mutation ; Pedigree ; Polycystic Kidney, Autosomal Dominant/genetics* ; Pregnancy ; Prenatal Diagnosis ; TRPP Cation Channels/genetics*

The purpose of the present study was to determine the role of inositol 1,4,5-trisphosphate receptor 3 (IP₃R3) in renal cyst development in autosomal dominant polycystic kidney disease (ADPKD). 2-aminoethoxy-diphenyl borate (2-APB) and shRNA were used to suppress the expression of IP₃R3. The effect of IP₃R3 on cyst growth was investigated in Madin-Darby canine kidney (MDCK) cyst model, embryonic kidney cyst model and kidney specific Pkd1 knockout (PKD) mouse model. The underlying mechanism of IP₃R3 in promoting renal cyst development was investigated by Western blot and immunofluorescence staining. The results showed that the expression level of IP₃R3 was significantly increased in the kidneys of PKD mice. Inhibiting IP₃R3 by 2-APB or shRNA significantly retarded cyst expansion in MDCK cyst model and embryonic kidney cyst model. Western blot and immunofluorescence staining results showed that hyperactivated cAMP-PKA signaling pathway in the growth process of ADPKD cyst promoted the expression of IP₃R3, which was accompanied by a subcellular redistribution process in which IP₃R3 was translocated from endoplasmic reticulum to intercellular junction. The abnormal expression and subcellular localization of IP₃R3 further promoted cyst epithelial cell proliferation by activating MAPK and mTOR signaling pathways and accelerating cell cycle. These results suggest that the expression and subcellular distribution of IP₃R3 are involved in promoting renal cyst development, which implies IP₃R3 as a potential therapeutic target of ADPKD.
Animals ; Dogs ; Mice ; Cysts/genetics* ; Inositol 1,4,5-Trisphosphate Receptors/pharmacology* ; Kidney/metabolism* ; Polycystic Kidney Diseases/metabolism* ; Polycystic Kidney, Autosomal Dominant/drug therapy* ; Madin Darby Canine Kidney Cells

OBJECTIVETo detect gene mutation in the patients with autosomal dominant polycystic kidney disease (PKD).

METHODSPolymerase chain reaction (PCR)-denaturing high-performance liquid chromatography (DHPLC) analyses were performed in 3o single copy region of PKD 1 gene (PKD1). DNA sequencing were carried out on PCR products with abnormal peak shape afterwards.

RESULTSA new nonsense mutation (C11901A in exon 42 of PKD1 was identified to cause serine in position 3897 turning to a stop codon. A missense mutation, C10737T, was detected in exon 35 which caused threonine in position 3509 turn to methionine. Two kinds of samesense mutation, G11824A and C11860T in exon 42, were found in normal control.

CONCLUSIONPKD1 mutation were detected successfully by PCR-DHPLC. A new nonsense mutation, a missense mutation and two polymorphisms are identified in this study.

Adult ; Codon, Nonsense ; Female ; Humans ; Male ; Mutation, Missense ; Polycystic Kidney Diseases ; genetics ; Polycystic Kidney, Autosomal Dominant ; genetics ; TRPP Cation Channels ; genetics ; Young Adult

OBJECTIVETo identify potential mutations of PKD1 gene in a family affected with autosomal dominant polycystic kidney disease (ADPKD).

METHODSThe coding regions of the PKD1 gene were subjected to PCR and Sanger sequencing. Reverse transcription-PCR (RT-PCR) was used to determine the relative mRNA expression in the patient.

RESULTSA splicing site mutation, c.8791+1_8791+5delGTGCG (IVS23+1_+5delGTGCG), was detected in the PKD1 gene in all 5 patients from the pedigree but not in 6 phenotypically normal relatives and 40 healthy controls. Sequencing of RNA has confirmed that there were 8 bases inserted in the 3' end of exon 23 of the PKD1 gene.

CONCLUSIONThe novel c.8791+1_8791+5delGTGCG mutation has created a new splice site and led to a frameshift, which probably underlies the ADPKD in the family. Above finding has enriched the mutation spectrum of the PKD1 gene.

Adult ; Female ; Humans ; Male ; Mutation ; genetics ; Pedigree ; Polycystic Kidney, Autosomal Dominant ; genetics ; RNA Splicing ; genetics ; TRPP Cation Channels ; genetics ; Young Adult