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Objective:To analyze and summarize the clinical, genotypic and pathological characteristics of children with PAX2 gene mutation in China, and to provide information for the monitoring, treatment and prognosis of the disease. Methods:It was a case series analysis study. The clinical data of children with PAX2 gene mutation in Pediatric Nephrology Department, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology from January 2014 to December 2022 were collected, and peripheral blood gene DNA was extracted and sequenced for whole exome sequencing. The clinical, pathological and genotypic characteristics of PAX2 gene variation of children in China were summarized by searching PubMed, Medline, China National Knowledge Infrastructure and Wanfang database and compared with the cases in this single center. Results:Among the 13 children with PAX2 gene mutation, there were 9 males and 4 females, 12 patients with abnormal urine tests, 7 patients with small kidney volume by imaging examination, and 5 patients with renal cysts. The clinical phenotypes were congenital renal and urinary tract malformations in 8 cases, renal coloboma syndrome in 1 case, and hematuria or proteinuria in 3 cases. Five patients underwent renal biopsies, showing focal segmental glomerulosclerosis and C3 glomerulopathy in 1 case, focal segmental glomerulosclerosis in 1 case, thin basement membrane lesion in 1 case, and IgA nephropathy in 2 cases. The genetic testing in 13 children showed 9 de novo mutations and 4 new mutations of c.321G>A, c.213-8C>G, c.63C>A and c.449C>T. There were 2 cases of 76dupG (p.V26Gfs*28) mutant. A total of 51 Chinese children with PAX2 gene mutation were found in the literature search. There were 32 males and 19 females, 8 cases with small kidney volume and 12 cases with renal cysts. The clinical phenotypes were congenital anomalies of kidney and urinary tract in 28 cases, renal coloboma syndrome in 17 cases, and hematuria or proteinuria in 6 cases. Seven patients underwent renal biopsies, including 2 cases with focal segmental glomerulosclerosis, 1 case with minimal lesion, 1 case with mesangial proliferative glomerulonephritis, 1 case with IgA nephropathy, 1 case with membranous nephropathy and a case with focal proliferative sclerosing purpura nephritis combined with glomerular hypertrophy. Thirty-four cases were de novo mutations, and 12 mutations were from the father or mother. The father or mother of 5 children had no clinical manifestations, with normal renal function. There were 11 cases of 76dupG (p.V26Gfs*28) mutant. Conclusions:The clinical phenotypes and genotypes of PAX2 gene variation in Chinese children are diverse. The most common clinical phenotype of PAX2 gene variation is congenital anomalies of kidney and urinary tract. c.76dupG (p.V26Gfs*28) is the most common of PAX2 gene variant.
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Objective:To determine a relationship between ultrasound shear wave elastography (SWE) and pathological lessions of renal tissues in children with chronic kidney disease (CKD).Methods:It was a cross-sectional observational study, involving children admitted to the Department of Pediatrics of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from January to December 2021 with definite pathological diagnosis through kidney biopsy. The SWE was used to determine the Young's modulus (elastic modulus) of the cortex and medulla of the upper, middle, and lower poles of the kidney. The renal histopathology was classified or graded. The statistical method was used to analyze the relationship between Young's modulus of the inferior polar cortex (YM cor) and medulla (YM med) of the right kidney and renal pathology. Results:The study included 110 children with definite pathological diagnosis through renal biopsy, aged (10.1±3.4) years old (2-17 years old), with 55 males (50.0%). The body mass index was (20.6±2.4) kg/m 2, and mean arterial pressure was (95±24) mmHg. There were 94 patients (85.4%) with CKD stage 1, 8 patients (7.3%) with CKD stage 2, and 8 patients (7.3%) with CKD stage 3. There was no significant difference of YM cor and YM med in the upper and middle poles of the right kidneys, and YM med in the lower poles of right kidneys in CKD patients with different stages (all P>0.05). Both YM cor [(15.75±3.36) kPa] and YM med [(13.50±2.43) kPa] of CKD stage 3 patients were significantly higher than those of CKD stage 1 patients [(12.94±2.45) kPa, (11.88±2.23) kPa](both P<0.05). There was no significant difference of YM cor and YM med in the lower poles of right kidneys between stage 1 and stage 2 CKD patients (both P>0.05). YM cor[(17.93±3.23) kPa] and YM med [(15.50±1.48) kPa] in patients with crescentic glomerulonephritis were higher than those in patients with focal segmental glomerulosclerosis [(12.71±2.42) kPa, (11.57±2.63) kPa] and mesangial proliferative glomerulonephritis [(12.73±2.04) kPa, (11.48±2.10) kPa](all P<0.05). There was no significant difference of YM cor and YM med between focal segmental glomerulosclerosis and mesangial proliferative glomerulonephritis (both P>0.05). YM cor [(16.30±2.63) kPa] and YM med [(15.54±1.59) kPa] of Lee's Ⅳ grade of IgA nephropathy were higher than those of Lee's Ⅲ grade [(13.32±2.70) kPa, (12.57±2.50) kPa](both P<0.05), while the International Study of Kidney Disease in Children grade of purpura nephritis had no significant correlation with YM cor and YM med (both P>0.05). YM cor [(15.41±2.37) kPa] and YM med [(13.82±2.59) kPa] of interstitial fibrosis/tubular atrophy (T1/T2) group of IgA nephropathy mixed with purpura nephritis were significantly higher than those of T0 group's [(12.99±2.40) kPa, (11.79±2.05) kPa] (both P<0.05). Moreover, crescent formation (C1) group had a higher YM cor [(14.21±2.77) kPa] and YM med [(12.80±2.47) kPa] than those in C0 group [(12.73±2.15) kPa, (11.59±1.97) kPa] (both P<0.05), while YM cor and YM med were unrelated to the mesangial hypercellularity (M), endocapillary cellularity (E), segmental sclerosis or adhesion (S) indicators (all P>0.05). In lupus nephritis patients, YM cor ( r=0.744, P=0.035) and YM med ( r=0.728, P=0.009) were favorably linked with the chronic index, but not with the activity index (both P>0.05). Conclusions:Renal interstitial fibrosis/tubular atrophy and crescentic development are connected with YM cor and YM med at the lower pole of the kidney as measured by SWE. SWE can be used to assess the chronic renal lesions in children with CKD in the early and middle stages. It may develop into a new noninvasive way to assess renal pathology.