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.

Clinical phenotype and genotype analysis of infantile polycystic kidney:a case report / 临床儿科杂志

Objective To explore the clinical phenotype and genotype characteristics of infantile polycystic kidney. Method The clinical data of polycystic kidney disease in one infant were retrospectively analyzed, and the correlation between clinical phenotype and genotype was analyzed. Results In this infant the polycystic kidney was discoved in the fetal period, and shortness of breath, foaming at the mouth were present after birth. Abdominal magnetic resonance imaging indicated that there was medullary sponge kidney in both kidneys accompanied by mild effusion and cysts were found in the right kidney. Gene detection showed a missense mutation c.1123 C>T (Arg375Trp) of exon15 in PKHD1 gene. The exon31 of PKHD1 gene had a missense mutation c.3617G>T (Gly1206Val), which was a new missense mutation. The exon18 of PKD1 gene had a missense mutation c.7211G>A (Arg2404Gln), which is a complex heterozygous mutant of homozygote. All of the mutations are missense mutations. The infant was improved and discharged after treatment, and renal function was normal during 4 months of follow-up. Conclusion Gene detection can be used for early diagnosis of infantile polycystic kidney disease. Newborns with two missense mutations can survive, and exon31 mutation c.3617G>T (Gly1206Val) is a new finding.

Phenotype analysis of 9 cases with mutations in PKHD1 gene / 中华肾脏病杂志

Objective To summarize the clinical features of 9 cases with mutations in PKHD1 gene for a better understanding of its phenotype.Methods Clinical data of nine cases with mutations in PKHD1 gene were summarized from January 2011 to December 2016 in our center,including clinical manifestations,laboratory findings,imaging data and family investigation.Next generation sequencing was used to screen 4000 genes in case 1 to 4 and whole exons in case 5 to 9.Significant variants detected by next generation sequencing were confirmed by conventional Sanger sequencing.Segregation analysis was performed using parental DNA samples.Relevant literature was reviewed.Results Among these 9 cases,5 are male,4 are female.The average age of onset was 2.6 years old (ranging from 0.5-5.2 years).Renal ultrasound revealed that all 9 cases had cysts in bilateral kidney,7 cases with enlarged kidney,1 case with normal size kidney,1 case with normal size kidney,and 1 case with bilateral renal atrophy.Two cases with renal artery stenosis,1 case with focal narrowing in left main branch and 1 case with vesico-ureteral reflux were found.Among the 9 cases,3 cases had homozygous mutations,and 6 cases had compound heterozygous mutations,including 1 nonsense mutation,1 frameshift mutation and 15 missense mutations.There were 2 cases with 3 heterozygous mutations,2 c.5935C ＞ T mutations and 2 eases with C.5869G ＞ A mutations.A total of 10 new mutations were identified.Conclusion Patients with mutations in the PKHD1 gene had normal size kidney,or even atrophic kidney.Renal artery stenosis,vesicoureteral reflux and bronchial stenosis were all first reported in patients with mutations in PKHD1 gene.The novel mutations,c.274C ＞ T,c.9059T ＞ C,c.8996delG,c.281C ＞ T,c.10424T ＞ A,c.7092T ＞ G,c.4949T ＞ C,c.5869G ＞ A,c.6197A ＞ G and c.1877A ＞ G further expanded the mutation spectrum of PKHD1 gene.

Newly Detected PKHD1 Gene Mutation in a Newborn with Fatal Autosomal Recessive Polycystic Kidney Disease

Autosomal recessive polycystic kidney disease is among the most common inherited ciliopathies and is caused by mutations in the polycystic kidney and hepatic disease 1 (PKHD1) gene. Despite its great phenotypic variability, this condition is usually diagnosed during the neonatal and early infantile periods. We report a 37+3 -gestational-week neonate presenting with fatal autosomal recessive polycystic kidney disease who died at 28 hours of life from severe respiratory failure. The familial history is significant because a previous sibling died in utero at 24+2 weeks of gestational age and was diagnosed with polycystic kidney disease based on prenatal ultrasonography and autopsy. Our patient's autopsy revealed findings compatible with polycystic kidney disease. In addition, a PKHD1 gene study of peripheral blood leukocytes identified the compound heterozygote mutation c.274C>T(p.Arg92Trp), as well as the novel heterozygous nonsense mutation c.2770C>T(p.Gln924*).

Effect of fibrocystin on the proliferation of kidney cyst epithelial cells in autosomal recessive polycystic kidney disease / 中华肾脏病杂志

Objective To explore whether the inhibited expression of fibrocystin by RNA interference can increase epidermal growth factor (EGF)-induced cell proliferation and its possible mechanism . Methods A stable PKHD1-silenced HEK 293 cell line was established . Cell proliferation rate, intracellular Ca2+ concentration and extracellular signal-reguhted kinase 1/2(ERK1/2) activity were assessed after treatment with EGF, verapamil and Bay K8644 . Results The proliferation rate of PKHD1-silenced HEK-293 cells was found to be significantly higher after EGF stimulation compared to the control HEK 293 cell (231 .5% vs 152 .8%, P＜0 .01) . PKHD1-silencing lowered the intracellular Ca2+ concentration and caused EGF-induced ERK1/2 overactivation in the cells(P＜0 .01 ) . When cells were treated with verapamil for 4 hours to lower the intracellular Ca2+ concentration, the cell proliferation rate was significantly increased after 20 ng EGF for 24 hours . The verapamil treatment increased the level of activated ERK1/2 in EGF-treated cells . An increase of intracellular Ca2 + in PKHD1-silenced ceils repressed the EGF-dependent ERK1/2 activation and the hyperproliferative response to EGF stimulation . Conclusions Inhibition of fibrocystin can cause EGF-induced excessive proliferation through decreasing intracellular Ca2+ resulting in EGF-induced ERK1/2 activation . The loss of fibrocystin may lead to abnormal proliferation in kidney epithelial cells and cyst formation in ARPKD through modulation of intracellular Ca2+ concentration .