Mutational analysis of MYO1E in Chinese children with familial steroid-resistant nephrotic syndrome / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Steroid-resistant nephrotic syndrome (SRNS) with MYO1E mutations has been identified as autosomal recessive focal segmental glomerulosclerosis (FSGS). To date, only two homozygous mutations in the MYO1E gene were reported in three families with FSGS. This study aimed to examine mutations in the MYO1E gene in children with familial SRNS in the Han Chinese ethnic group.</p><p><b>METHODS</b>Between 2005 and 2010, peripheral blood samples were collected from the probands, their siblings and parents of four families with autosomal recessive SRNS in the Han Chinese ethnic group. Four probands were studied from nine patients. The mutational analysis of MYO1E was performed by polymerase chain reaction and direct DNA sequencing. Fifty-nine healthy volunteers with normal urine analysis were included as controls.</p><p><b>RESULTS</b>Twenty-five MYO1E variants in the prohands from 4 families with SRNS were identified in this study. Among them, 24 variants were found in NCBI dbSNP. One heterozygous mutation IVS21-85G>A was found in the prohand from Family D, whereas it was absent in 59 normal Chinese controls. No splice site change caused by IVS21-85G>A was reported by analysis with NetGene2.</p><p><b>CONCLUSIONS</b>MYO1E mutations are not a major cause of Chinese familial SRNS in this study.</p>

Mutations in NPHS2 in familial steroid-resistant nephrotic syndrome in Southern Chinese Han ethnic group / 中华儿科杂志

<p><b>OBJECTIVE</b>Mutations in NPHS2 mapped to 1q25-q31 and encoding podocin, which is exclusively expressed in glomerular podocytes, are responsible for autosomal recessive familial steroid-resistant nephrotic syndrome (SRNS) with minor glomerular abnormalities or focal segmental glomerulosclerosis. Different groups from European and North American countries have screened NPHS2 mutations in familial SRNS with recessive inheritance, documenting a mutation detection rate of 45% - 55% in families. This study aimed to examine mutations in the NPHS2 gene in Southern Chinese Han ethnic group patients with familial SRNS.</p><p><b>METHODS</b>Genomic DNA from 3 probands from Southern Chinese Han families with autosomal recessive SRNS, and their siblings and parents was isolated and analyzed for all eight exons, exon-intron boundaries and promoter of NPHS2 using the polymerase chain reaction and direct sequencing.</p><p><b>RESULTS</b>No mutation of NPHS2 in all eight exons and exon-intron boundaries was identified in the 3 probands. However, a polymorphism of 954T > C in exon 8 was detected in all the 3 probands and some controls, and 5 variants of NPHS2 promoter, -1709G > A, -1000A > T, -670C > T, -116C > T and -51G > T, were identified in some patients and controls, indicating that these variants are polymorphisms. One heterozygous variant of NPHS2 promoter, -1715A > G, was also identified in one proband and her mother whose urinalyses were normal, whereas it was not found in any of the 50 controls. There was no significant difference in the allelic frequencies of -1709G > A, -1000A > T, -670C > T, -116C > T and -51G > T polymorphisms between the patients and controls.</p><p><b>CONCLUSION</b>NPHS2 mutations are not a major cause of familial steroid-resistant nephrotic syndrome in Southern Chinese Han ethnic group included in the study.</p>

Treatment of hemolytic uremic syndrome after acute stage / 中华儿科杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

A novel mutation of NPHS2 identified in a Chinese family with steroid-resistant nephrotic syndrome / 中华儿科杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Mutations in NPHS2 Gene in A Child with Steroid-Dependent Nephrotic Syndrome / 实用儿科临床杂志

T were also detected in the controls.Conclusion Nephrotic syndrome may be associated with NPHS2 identified in children.