Phenotype and genetic analysis of three patients with PKHD1 associated autosomal recessive polycystic kidney disease at childhood, teenage and advanced age / 中华医学遗传学杂志

Objective@#The phenotype and genetics of three patients with autosomal recessive polycystic kidney disease (ARPKD) at childhood, teenage and advanced age were analyzed.@*Methods@#Next generation sequencing (NGS) was applied to all the probands. PCR and Sanger sequencing were used to verify the suspicious gene variants screened by NGS in the probands and their family members, and one of the family got prenatal diagnosis.@*Results@#Through NGS, PCR and Sanger sequencing, the 5-yr proband in pedigree 1 was shown to carry compound heterozygous variants of c. 5935G>A(p.G1979R) and c. 5428G>T(p.E1810X) of PKHD1, originated from his parents; In pedigree 2, the 17-ys proband was detected with c. 5512T>C(p.Y1838H) and c. 5935G>A(p.G1979R) variants of PKHD1 orginated from her parents, and her mother also got prenatal diagnosis during the second trimester; In pedigree 3, the 70-ys female proband was found with variants c. 11314C>T (p.R3772X) and c. 3860T>G (p.V1287G) of PKHD1.@*Conclusion@#The three pedigrees were diagnosed as ARPKD caused by PKHD1 variants. Five types of variants were detected, c. 5935G>A and c. 11314C>T were the known pathogenic variants, while c. 5512T>C, c. 5428G>T and c. 3860T>G were not reported previously. Considering the complexity of the genetics and phenotypes of the cystic renal diseases, genetic diagnosis is crucial to give accurate etiological diagnosis, which may benefit the clinic management.

Genetic analysis of the PKHD1 gene with long-rang PCR sequencing / 华中科技大学学报（医学）（英德文版）

PKHD1 gene mutations are found responsible for autosomal recessive polycystic kidney disease (ARPKD). However, it is inconvenient to detect the mutations by common polymerase chain reaction (PCR) because the open reading frame of PKHD1 is very long. Recently, long-range (LR) PCR is demonstrated to be a more sensitive mutation screening method for PKHD1 by directly sequencing. In this study, the entire PKHD1 coding region was amplified by 29 reactions to avoid the specific PCR amplification of individual exons, which generated the size of 1 to 7 kb products by LR PCR. This method was compared to the screening method with standard direct sequencing of each individual exon of the gene by a reference laboratory in 15 patients with ARPKD. The results showed that a total of 37 genetic changes were detected with LR PCR sequencing, which included 33 variations identified by the reference laboratory with standard direct sequencing. LR PCR sequencing had 100% sensitivity, 96% specificity, and 97.0% accuracy, which were higher than those with standard direct sequencing method. In conclusion, LR PCR sequencing is a reliable method with high sensitivity, specificity and accuracy for detecting genetic variations. It also has more intronic coverage and lower cost, and is an applicable clinical method for complex genetic analyses.

Autosomal Recessive Polycystic Kidney Disease Confirmed to PKHD1 Gene Mutation: A Case of PKHD1 Gene Mutation

Autosomal recessive polycystic kidney disease (ARPKD) is a severe form of polycystic kidney disease that is characterized by enlarged kidneys and congenital hepatic fibrosis. The clinical spectrum of this condition shows wide variation. Approximately 30-50% of affected individuals die in the neonatal period, while others survive into adulthood. ARPKD is caused by mutations in the polycystic kidney and hepatic disease 1 (PKHD1) gene on chromosome 6p12, which consists of 86 exons variably assembled into many alternatively spliced transcripts. We report a case of a pathogenic PKHD1 frameshift mutation, c.889_931del43, which was identified using direct full sequencing, associated with enlarged cystic kidneys and dilatation of intrahepatic bile duct, as observed on imaging studies.

Genetic Basis And Clinical Features Of Polycystic Kidney Disease / Монголын Анагаах Ухаан

Autosomal dominant PKD (ADPKD) is the most common monogenic genetic disease, and affects one in 500–1000 humans. Approximately half of all affected patients develop end-stage renal disease in the fifth to sixth decade of life. In a majority of cases (80-85%), the gene involved is PKD1, which is located on chromosome 16 (16q13.3) and encodes polycystin-1, a large receptor-like integral membrane protein that contains several extracellular mo-tifs indicative of cell-cell and cell-matrix interaction. In the remaining (10-15%) cases, the disease is milder and is caused by mutational changes in another gene (PKD2), which is located at chromosome 4 (4q21-23) and encodes polycystin-2, a transmembrane protein, which acts as a nonspecific calcium-permeable channel. ADPKD is gener¬ally a late-onset multisystem disorder characterized by bilateral renal cysts; cysts in other organs including the liver, seminal vesicles, pancreas, and arachnoid membrane; vascular abnormalities including intracranial aneurysms, dilatation of the aortic root, and dissection of the thoracic aorta; mitral valve prolapse; and abdominal wall hernias. Renal manifestations include hypertension, renal pain, and renal insufficiency. PKD1 and PKD2 gene mutations result in similar extra-renal manifestations, including PLD and intracranial aneurysms. Autosomal recessive polycystic kidney disease (ARPKD) is an important cause of childhood renal- and liver-related morbidity and mortality with variable disease expression. While most cases manifest peri-/neonatally with a high mortality rate in the first month of life, others survive to adulthood. ARPKD is caused by mutations in the Polycystic Kidney and Hepatic Disease 1 (PKHD1) gene on chromosome 6p12. PKHD1 is an exceptionally large gene (470 kb) with a longest open reading frame transcript of 67 exons predicted to encode a 4,074-amino acid (aa) (447 kDa) multidomain integral membrane protein (fibrocystin/polyductin) of unknown function.

Klotho: a protein molecule interacting with FPC protein / 中国病理生理杂志

AIM: To investigate the role of fibrocystin/polycystin (FPC) in autosomal recessive polycystic kidney disease (ARPKD) development by means of screening the protein interaction using yeast two-hybrid approach. METHODS: The constructed pGBKT7-FPC was used as the bait to screen the pre-transformed human fetal kidney cDNA expression library by yeast two-hybrid assay to obtain the host cell protein which interacted with C-terminal region of FPC. The sequence transformation screening experiment was applied to confirm the protein interactions in yeast. RESULTS: After yeast mating and co-transformation screening analysis, Klotho (KL) was selected from the host cells and the interaction between KL and FPC was further confirmed. CONCLUSION: C-terminal region of FPC can interact with KL, which probably provide the approach for further studying the role and biochemistry mechanism of FPC protein in ARPKD.

Doença renal policística autossômica recessiva: relato de caso e revisão de literatura / Autosomal recessive polycystic kidney disease: case report and review

A doença renal policística autossômica recessiva é uma desordem herdada com dilatações císticas nos ductos coletores freqüentemente associada com envolvimento hepático, hipertensão, insuficiência renal, hipertensão portal e retardo de crescimento. Mutações no gene PKHD1 (polycystic kidney and hepatic disease 1) são responsáveis por todas as formas típicas desta enfermidade. Criança do sexo feminino, recém-nascida, primogênita de uma gestação normal, com peso de 2.470g apresentou massa abdominal palpável. A família não apresenta história para doença policística renal. Hipertensão arterial foi diagnosticada aos três meses. Exames laboratoriais normais. Tomografia abdominal demonstrou que ambos os rins estavam aumentados (7,8cm para o rim direito e 7,9cm rim esquerdo, em plano longitudinal), apresentando hiperecogenicidade cortical e fígado normal. A pressão arterial está parcialmente controlada com captopril, hidralazina e hidroclorotiazida após um ano de seguimento. Apresenta desenvolvimento neurológico e função renal normais. A grande maioria das crianças afetadas com ARPKD desenvolvem precocemente hipertensão arterial e precisam de rigoroso controle. Relatamos um caso diagnosticado ao nascimento e bem controlado clinicamente até o momento, com um ano de idade.

Autosomal recessive polycystic kidney disease (ARPKD) is an inherited disorder with cystic dilatations of the collecting ducts, frequently associated with hepatic involvement, hypertension, renal failure, portal hypertension and growth retardation. Mutations in the PKHD1 (polycystic kidney and hepatic disease 1) gene are responsible for all typical forms of this disease. A female newborn, firstborn of a normal pregnancy, weighing 2,470 g, presented palpable bilateral abdominal masses. Family history was negative for polycystic kidney disease. Arterial hypertension was diagnosed at three months of age. Laboratory tests were normal. Abdominal CT scan showed that both kidneys were enlarged (right kidney with 7.8 cm and left kidney with 7.9 cm, longitudinal plane), presenting cortical hyperechogenicity, and normal liver. Blood pressure was partially controlled by captopril, hydralazine and hydrochlorothiazide after one year of follow-up. The patient presents normal neurological development and normal kidney function. Children affected with ARPKD frequently develop arterial hypertension and require rigorous control. We report a case diagnosed at birth and clinically well-controlled so far, at the age of one year.

Caroli's Syndrome with Autosomal Recessive Polycystic Kidney Disease in a Two Month Old Infant

Caroli's syndrome is a rare congenital disorder that involves intrahepatic bile duct ectasia and congenital hepatic fibrosis, frequently seen with concomitant autosomal recessive polycystic kidney disease (ARPKD). Literature on infants with ARPKD is rare. Here, we present a case of a two month old boy who was diagnosed with Caroli's syndrome and ARPKD.

Longterm Follow-up of Autosomal Recessive Polycystic Kidney Disease

PURPOSE: This study was aimed to assess the clinical manifestations and courses of autosomal recessive polycystic kidney disease (ARPKD). METHODS: The medical records of 10 children diagnosed as infantile or juvenile ARPKD at Seoul National University Children's Hospital between January, 1984 and December, 1996, were reviewed, retrospectively. RESULTS: The average age at diagnosis was 3 8/12 years (4months-7 3/12 years) and sex ratio was 1 : 1. The mean follow-up duration was 8 5/12 years. Family history of renal cystic disease or hepatic fibrosis was not detected in any cases. Bilateral enlarged kidneys were noted in 2 cases and hepatosplenomegaly in all cases. Renal function had been maintained normally in all cases during follow-up. Urinary abnormalities were revealed in 4 cases and hypertension in 2 cases. Although liver enzyme levels were normal in all cases, esophageal varix was detected in 6 cases by gastrofiberscopy, and two of them received Warren shunt operation. The shunt operation did not affect the progression of the renal lesion. In 2 patients, who were diagnosed initially as congenital hepatic fibrosis, the renal cystic changes of ARPKD were detected 3 years and 6 years later. CONCLUSION: Because of the heterogeneous clinical spectrum and variable rate of progression of renal and hepatic lesion in ARPKD, the detection rate may vary. So patients, suspected to have ARPKD or congenital hepatic fibrosis, should be regularly followed up to detect latent renal lesion through radiological or pathological studies.

Klotho:a protein molecule interacting with FPC protein / 中国病理生理杂志

AIM:To investigate the role of fibrocystin/polycystin (FPC) in autosomal recessive polycystic kidney disease (ARPKD) development by means of screening the protein interaction using yeast two-hybrid approach. METHODS:The constructed pGBKT7-FPC was used as the bait to screen the pre-transformed human fetal kidney cDNA expression library by yeast two-hybrid assay to obtain the host cell protein which interacted with C-terminal region of FPC. The sequence transformation screening experiment was applied to confirm the protein interactions in yeast. RESULTS:After yeast mating and co-transformation screening analysis,Klotho (KL) was selected from the host cells and the interaction between KL and FPC was further confirmed. CONCLUSION:C-terminal region of FPC can interact with KL,which probably provide the approach for further studying the role and biochemistry mechanism of FPC protein in ARPKD.