Scalp Tumor and Hydroureteronephrosis in Patients with Nephronophthisis and Homozygous NPHP1 Deletion.

Homozygous deletion of NPHP1 can lead to isolated nephronophthisis (NPHP) and syndromic disorders. However, the phenotype of scalp tumor and hydroureteronephrosis in NPHP patients with homozygous deletion of NPHP1 has not been reported. Clinical data, laboratory results, and genetic testing of 4 NPHP patients were collected. Examination of their eyes, heart, and urinary tract and of their hepatobiliary, skeletal, and central nervous systems was evaluated. Isolated NPHP was observed in 1 case, and syndromic disorders were observed in the other 3 patients. Their syndromic disorders showed NPHP combined with central nervous system defects, eye involvement, scalp tumor, arachnoid cyst, or hydroureteronephrosis. Large homozygous deletions covering the whole NPHP1 gene locus were identified in all 4 patients. We report a novel phenotype of scalp tumor and hydroureteronephrosis in NPHP patients with homozygous deletion of NPHP1, paving an avenue for further research on NPHP1-associated deformity in the skin and the urinary system.

Peroxisome Elevation Induces Stem Cell Differentiation and Intestinal Epithelial Repair.

Epithelial-repair-dependent mucosal healing (MH) is associated with a more favorable prognosis for patients with inflammatory bowel disease (IBD). MH is accomplished via repair and regeneration of the intestinal epithelium. However, the mechanism underlying MH is ill defined. We found a striking upregulation of peroxisomes in the injured crypts of IBD patients. By increasing peroxisome levels in Drosophila midguts, we found that peroxisome elevation enhanced RAB7-dependent late endosome maturation, which then promoted stem and/or progenitor-cell differentiation via modulation of Janus Kinase (JAK) and Signal Transducer and Activator of Transcription (STAT)-SOX21A signaling. This in turn enhanced ISC-mediated regeneration. Importantly, RAB7 and SOX21 were upregulated in the crypts of IBD patients. Moreover, administration of drugs that increased peroxisome levels reversed the symptoms of dextran sulfate sodium (DSS)-induced colitis in mice. This study demonstrates a peroxisome-mediated epithelial repair mechanism, which opens a therapeutic avenue for the enhancement of MH in IBD patients.

Rethinking genotype-phenotype correlations in papillorenal syndrome: a case report on an unusual congenital camptodactyly and skeletal deformity with a heterogeneous PAX2 mutation of hexanucleotide duplication.

Papillorenal syndrome (PRS), an autosomal dominant inherited condition, is clinically featured by renal hypoplasia and optic nerve dysplasia. Based on current knowledge of genotype-phenotype correlations in PRS, mutations in the Paired box 2 (PAX2) gene have been recognized as a critical pathogenesis of typical renal and optic disease manifestations. However, little information is currently available on the skeletal abnormalities of PRS and the potential contribution of PAX2 mutations. Here, we present a case of a 10-year-old female PRS patient with the typical features of chronic renal failure and severe myopia, but was unexpectedly discovered camptodactyly of her left middle finger which affects the proximal interphalangeal joint. Pathologically, the camptodactyly was further indicated by radiology as a skeletal deformity, demonstrating a decline of bone mineral density and disappearance of joint space. Molecular diagnostics revealed a heterozygous mutation, 220_225dup, in the exon 3 of her PAX2 gene, which is de novo considering the lack of this mutation in her non-consanguineous parents. This mutation leads to duplication of glutamic acid at position 74 and tyrosine at position 75 in PAX2 protein, which may influence the DNA-binding function. Besides, the absence of Spalt like transcription factor 4 (SALL4) mutation excluded the diagnosis of acro-renal-ocular syndrome (AROS), of which clinical characteristics are similar to our patient's. This case unravels a previously unrecognized phenotype of camptodactyly due to a significant skeletal deformity of PRS with a heterogeneous PAX2 mutation of hexanucleotide duplication. This report challenges against the current belief of genotype-phenotype correlations in PRS.

A child with isolated nephrotic syndrome and WT1 mutation presenting as a 46, XY phenotypic male.

Mutations in the WT1 gene can lead to Denys-Drash syndrome or Frasier syndrome and can also cause isolated nephrotic syndrome (NS). Most patients with isolated NS caused by WT1 mutations present as 46, XX phenotypic females. There have been two cases with an onset age younger than 3 years with isolated NS caused by WT1 mutations presenting as 46, XY phenotypic males. We present a 46, XY phenotypic male patient with isolated NS and end-stage renal disease (ESRD) at the age of 6.3 years. He had normal male external genitalia with normal penis length and soft and normal volume of both testes. A mutation, 1051A>G (K351E), in exon 8 of WT1 was identified in the patient. After starting hemodialysis, manifestations of hypertension and renal failure improved, but he died at 6.8 years of age as a result of respiratory failure and heart failure. Our study supports the necessity of searching for mutations in WT1 in 46, XY phenotypic male patients with isolated NS and ESRD.

Discordant phenotypes in monozygotic twins with identical de novo WT1 mutation.

Mutations in the WT1 gene, leading to Denys-Drash syndrome and Frasier syndrome, can also cause isolated steroid-resistant nephrotic syndrome (ISRNS). Previous studies have reported six pairs of monozygotic twins with WT1 mutations, including one presenting with discordant phenotypes with identical WT1 mutations being of paternal origin and five pairs of monozygotic twins presenting the same phenotype with identical WT1 mutations. In this study, we report on female monozygotic twins showing discordant phenotypes with an identical de novo WT1 mutation, R394W, and presenting incomplete Denys-Drash syndrome and ISRNS.

A simple automated device for children's renal biopsy: advantage in obtaining more tissue.

Sufficient tissue yield is essential for renal biopsy. We have developed a simple automated renal biopsy device (Chen device) that constantly obtains more tissue. Since the Bard device is extensively used around the world, we compared our device with the Bard device. Pediatric patients were biopsied with either the Chen (n=247) or Bard (n=200) devices. No major complications were encountered and the incidence of minor complications was comparable between two devices. However, the average length of tissue obtained by the Chen device per biopsy (1.78±0.73 cm) was significantly longer than that obtained by the Bard device (1.23±0.45 cm). Accordingly, 61.94% of biopsies with the Chen device had 20 or more glomeruli, whereas only 18% of biopsies with the Bard device had this number (p<0.001). Thus, the Chen device has the advantage of obtaining more renal tissue per biopsy while being equally efficient and safe as the Bard device.

Genetic variations of the NR3C1 gene in children with sporadic nephrotic syndrome.

Previous studies have demonstrated that the genetic variations of glucocorticoid receptor gene (NR3C1) are associated with both familial steroid resistance and acquired steroid resistance in some diseases, such as Cushing's disease, leukemia, lupus nephritis, and female pseudohermaphroditism. In this study, we examined the genetic variations of NR3C1 in 35 children with sporadic steroid-resistant nephrotic syndrome (SRNS), and in 83 cases with sporadic steroid-sensitive NS (SSNS) using polymerase chain reaction, denaturing high-performance liquid chromatography and DNA sequencing, and analyzed possible associations between NR3C1 variants and steroid resistance in sporadic NS. No causative mutations were found; however, six previously identified and six novel polymorphisms, 1206C > T, 1374A > G, 2382C > T, 2193T > G, IVS7-68_-63delAAAAAA, and IVS8-9C > G, were detected. Two novel haplotypes, [1374A > G; IVS7-68_-63delAAAAAA; IVS8-9C > G; 2382C > T] and [1896C > T; 2166C > T; 2430T > C], of NR3C1 were also identified in sporadic NS and controls. The odds ratios (95% Confidence Interval) for the two novel NR3C1 haplotypes in the sporadic nephrotic children at risk of steroid resistance were 4.970 (0.889-27.788) and 2.194 (0.764-6.306), respectively, but the association between NR3C1 haplotypes and steroid resistance was not significant. Further studies on the possible association between the two novel NR3C1 haplotypes and steroid resistance in sporadic NS in larger cohorts are required.

[Treatment of hemolytic uremic syndrome after acute stage].

OBJECTIVE: Hemolytic uremic syndrome (HUS) is a common primary disease that can cause acute renal failure in childhood. Renal disease is the most important long-term complication in patients who survived the acute stage of HUS. Use of angiotensin-converting enzyme inhibitors (ACEI) and a restricted protein intake may be beneficial to the patients. However, it is not established whether such patients should be treated with steroids and immunosuppressors. The present study aimed to probe into the benefit of using steroid and immunosuppressor in patients after acute stage of HUS. METHODS: The subjects included 17 patients (aged 9 months to 15 years, 12 males, 5 females) with HUS. Thirteen patients recovered from the acute stage of HUS, and underwent continuative treatment and follow-up. All the patients were treated with ACEI and early restriction of protein intake. Additionally, 2 children manifested as glomerulonephritis, one was treated with triperygium glycosides. Other 11 children who manifested as nephrotic syndrome were treated with prednisone, among them 5 children had no response or had incomplete response to prednisone, for these children short-term high dose cyclophosphamide or methylprednisolone pulse treatment were added; in 3 of the children short-term high dose methylprednisolone treatment was applied additionally for membranoproliferative glomerulonephritis and/or focal segmental glomerulosclerosis and crescentic glomerulonephritis. RESULTS: After follow-up for 2 months to 8 years, 4 patients with milder disease recovered, their blood pressure, renal function and urinalysis became normal, but 1 patient had recurrence. Among 9 patients with severe disease, 6 maintained normal blood pressure, recovered renal function and urinalysis, the other 3 patients failed to comply with treatment protocol and died during the 3rd, 9th and 13th month. The remainder (4 cases) gave up therapy and died on the 27th to 48th days of the course. CONCLUSION: The treatment applied in this study could improve the prognosis of patients after acute phase of HUS evidently by using the steroid and immuno suppressor according to clinical classification and pathological findings. It is recommended that triperygium glycosides is beneficial to children with glomerulonephritis, proteinuria and hematuria after acute stage of HUS. Adjustment of therapeutic schedule based on pathological findings after renal biopsy is helpful. To the patients with progressive renal failure who have no response to the steroid and immunosuppressors, steroid and immunosuppressor should be discontinued and dialysis treatment should be applied. Protocol compliance is also an important factor.

[A novel mutation of NPHS2 identified in a Chinese family with steroid-resistant nephrotic syndrome].

OBJECTIVE: Autosomal recessive steroid-resistant nephrotic syndrome (SRNS) is a subgroup of familial nephrotic syndrome. A causative gene has been identified, that is NPHS2, in chromosome 1q25-31, which encodes podocin. This study aimed to detect NPHS2 mutation in a Chinese family with SRNS. METHODS: Renal biopsy was performed on the proband and her sibling for routine histologic and immunohistochemical investigation and electron microscopic examination. The expressions of podocin, nephrin, alpha-actinin and WT1 in glomeruli of the proband were detected by indirect immunofluorescence. Peripheral blood samples were collected for genetic analysis from the proband and her parents, and 53 adults with normal urinalysis. Genomic DNA was isolated from peripheral blood leucocytes. Eight exons of NPHS2 were amplified by polymerase chain reaction. Mutational analysis was performed using denaturing high-performance liquid chromatography (DHPLC) and DNA fragments with aberrant elution profiles of both strands revealed by DHPLC were re-amplified and sequenced directly. RESULTS: The histologic findings on kidney biopsies were focal segmental glomerulosclerosis. In controls, the distribution of staining with P35, rabbit against a human podocin recombinant protein (amino acids 135 - 383 = all the C-terminal part of the protein downstream the transmembrane domain), and P21, rabbit against a human podocin recombinant protein (amino acids 15 - 89 = all the N-terminal part of the protein upstream the transmembrane domain) showed a linear pattern along glomerular capillary walls on glomeruli, and the fluorescent intensity of the staining with P35 was intensely positive. The fluorescent intensity of the staining with P21 was positive. In the proband, the distribution of the staining with P35 showed uneven and nonlinear, and the fluorescent intensity of the staining with P35 was weakly positive. The staining with P21 was negative. The area, location, distribution and fluorescent intensity of the staining with nephrin, alpha-actinin and WT1 on glomeruli of the proband were the same as those in the controls. The DHPLC elution profiles of exon 4 of NPHS2 from the proband and her parent were aberrant. The chromatograms by sequencing detected in the exon 4 of NPHS2 showed a composite heterozygous mutation of both 467_468insT and 503G > A in the proband, a heterozygous mutation of 503G > A in her father, and a heterozygous mutation of 467_468insT in her mother, respectively. CONCLUSION: The study demonstrated for the first time a novel mutation, 503G > A, of NPHS2 in Chinese kindred with autosomal recessive SRNS. A significantly decreased or negative expression was also revealed in glomeruli of the proband stained with two kinds of anti-podocin antibodies.

[The development and clinical applications of automatic negative pressure gun for biopsy].

Using the new negative pressure biopsy technology, the automatic negative pressure gun and the specific puncture needle for the biopsy have been developed. Renal biopsies were conducted in 1136 cases, with the success rate being 99.9%, and 29 cases gross hematuria while the hepatic biopsies were conducted in 16 cases, mass biopsies in 3 cases with the success rates being 100% respectively. The biopsy gun has the advantages of easy manipulation, higher success rate and lower incidence of complications.