Síndrome WAGR por deleción en heterocigosis del gen WT1: Caso clínico pediátrico / WAGR syndrome by heterozygous deletion of the WT1 gene: Pediatric case report

El síndrome WAGR (tumor de Wilms, aniridia, anomalías genitourinarias y retraso mental) es un trastorno genético infrecuente debido a la deleción de la región 11p13, que contiene los genes WT1 y PAX6. Comprende una combinación distintiva de afecciones clínicas; la aniridia y el tumor de Wilms son las más notables. Se presenta a un lactante de 17 meses con microcefalia, alteraciones oculares (buftalmos, leucocoria, aniridia bilateral), hipoplasia escrotal, testículos en la región inguinal y retraso en el neurodesarrollo, a quien se le realizó el estudio de amplificación de sondas dependiente de ligandos múltiples para WT1, que mostró haploinsuficiencia en las sondas que hibridaban la región 11p13, compatible con una deleción en heterocigosis del gen. Posteriormente, se diagnosticó tumor de Wilms. Dada su baja prevalencia, es importante difundir sus características clínicas y hacer énfasis en un manejo interdisciplinario centrado en la identificación precoz del síndrome y de sus posibles complicaciones. .

WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies and mental retardation) is an uncommon genetic disorder due to the deletion of the 11p13 region that contains the WT1 and PAX6 genes. It involves a distinctive combination of clinical conditions, with aniridia and Wilms tumor being the most notable. We present a 17-month-old infant with microcephaly, ocular alterations (buphthalmos, leukocoria, bilateral aniridia), scrotal hypoplasia, undescended testes and neurodevelopmental delay who underwent multiplex ligation-dependent probe amplification study for WT1, showing haploinsufficiency in the probes that hybridize to the 11p13 region, compatible with an heterozygous deletion of the gene. Wilms tumor was later diagnosed. WAGR syndrome is infrequent; its report in Latin America is low. It is important to disseminate its clinical characteristics, emphasizing an interdisciplinary management focused on the early identification of both the syndrome and its possible complications.

Clinical and pathological features and mutational types of WT1 mutation-associated nephropathy / 中华儿科杂志

Objective@#To explore the clinical and pathological features and mutational types and their relations with WT1 mutation-associated nephropathy (WT1MAN).@*Methods@#The clinical and pathological data and the results of WT1 mutation analysis of the cases from Nanfang Hospital of Southern Medical University, Sun Yat-sen Memorial Hospital and The First Affiliated Hospital of Sun Yat-sen University whom we recruited recently and reported during the last ten years were analyzed.@*Results@#Totally, 20 cases (6 males and 14 females), included 5 newly diagnosed cases, were recruited. (1) Ten children were diagnosed with Denys-Drash syndrome (DDS): The median onset age of proteinuria was 1 year and 7 months. Diffuse mesangial sclerosis (DMS) were revealed in 3 cases, minimal lesions (MCD) in 4 cases, and focal segmental glomerulosclerosis (FSGS) in 1 case; renal pathology was not available in the other 2 cases. Glomerular basement membrane (GBM) thickening was observed in 2 cases. Calcineurin inhibitors (CNIs) were administered in 5 cases, complete remission of proteinuria was observed in 3 cases, partial remission in the other 2 cases. Genetic analysis revealed that six cases had WT1 missense mutation, 3 had nonsense mutation, and 1 had frameshift mutation. (2) Two cases were diagnosed with Frasier syndrome (FS): proteinuria was observed at 1 year and 1 month of age and 1 year and 9 months of age, respectively. FSGS with GBM layering were observed in both cases. They progressed to ESRD at 1 year and 6 months of age and 6 years and 6 months of age, respectively. CNI was tried in 1 case with partial proteinuria remission. Both patients were detected to have WT1 splice mutation. (3) Isolated nephropathy (IN) was observed in 8 cases: three had splice mutation, 5 had missense mutation. Of the 3 patients with splice mutation, one was found to have nephropathy and renal failure at the age of 5 months. The other two cases (1 was FSGS and another MCD), both had GBM layering. CNIs were tried on both of them, one got partial remission with normal renal function at the age of fourteen years, the other one had no response and entered ESRD at the age of 6 years and 9 months. Of the 5 cases with missense mutation, 3 had DMS, 2 of them entered ESRD within 6 months of age, another case had DMS entered ESRD at 9 years of age. One case with FSGS, was treated with CNIs and got complete remission.@*Conclusions@#Slow progression (7/10) nephropathy was observed in DDS patients. Missense mutation (11/20) was the most common type of WT1 variants, followed by splice mutation (5/20) in this group of patients. Early onset nephropathy (4/5), rapid progression (4/5) and GBM layering (4/4) wereobserved in patients with splice mutation. CNI was effective in reducing or even eliminating proteinuria in WT1 MAN patients (8/9).

AAcute WT1-positive promyelocytic leukemia with hypogranular variant morphology, bcr-3 isoform of PML-RARα and Flt3-ITD mutation: a rare case report / Leucemia promielocítica aguda WT1-positivo com morfologia variante hypogranular, isoforma bcr-3 da PML-RARα e mutação Flt3-ITD: relato de caso raro

ABSTRACT CONTEXT: Acute promyelocytic leukemia (APL) accounts for 8% to 10% of cases of acute myeloid leukemia (AML). Remission in cases of high-risk APL is still difficult to achieve, and relapses occur readily. CASE REPORT: Here, we describe a case of APL with high white blood cell counts in blood tests and hypogranular variant morphology in bone marrow, together with fms-like tyrosine kinase-3 with internal tandem duplication mutations (FLT3-ITD), and bcr-3 isoform of PML-RARα. Most importantly, we detected high level of Wilms’ tumor gene (WT1) in marrow blasts, through the reverse transcription polymerase chain reaction (RT-PCR). To date, no clear conclusions about an association between WT1 expression levels and APL have been reached. This patient successively received a combined treatment regimen consisting of hydroxycarbamide, arsenic trioxide and idarubicin plus cytarabine, which ultimately enabled complete remission. Unfortunately, he subsequently died of sudden massive hemoptysis because of pulmonary infection. CONCLUSION: Based on our findings and a review of the literature, abnormal functioning of WT1 may be a high-risk factor in cases of APL. Further studies aimed towards evaluating the impact of WT1 expression on the prognosis for APL patients are of interest.

RESUMO CONTEXTO: Leucemia promielocítica aguda (LPA) compreende 8% a 10% dos casos de leucemia mieloide aguda (LMA). A remissão em casos de LPA de alto risco ainda é dificilmente conseguida, e recorrência é comum. RELATO DE CASO: Descrevemos aqui um caso de LPA com glóbulos brancos elevados no exame de sangue e a morfologia variante hipogranular na medula óssea, juntamente com fms-like tirosina-quinase-3 com mutações de duplicação em tandem interna (FLT3-ITD) e a isoforma bcr-3 de PML- RARα. Mais importante, detectamos alto nível de gene do tumor de Wilms (WT1) em blastos medulares por RT-PCR (reverse transcription polimerase chain reaction). Até agora, não há conclusões claras sobre a associação entre os níveis de expressão WT1 e APL. Este paciente recebeu sucessivamente regime de tratamento combinado, de hidroxicarbamida, trióxido de arsênico e idarrubicina e citarabina, alcançando finalmente a remissão completa. Infelizmente, em seguida, ele morreu de repente de hemoptise maciça devido a uma infecção pulmonar. CONCLUSÃO: Com base em nossos resultados e numa revisão da literatura, a função anormal de WT1 pode ser um fator de alto risco em casos de APL. Novos estudos, com o objetivo de avaliar o impacto da expressão de WT1 no prognóstico dos doentes com APL, são de interesse.

Simultaneous detection of WT1 and MDR1 gene expression in acute leukemia patients by a multiplex real time quantitative PCR method / 中华检验医学杂志

Objective To set up a multiplex real time quantitative PCR method to detect the expression of WT1 and MDR1 gene simultaneously in acute leukemia patient. Methods Total RNA was extracted from k562 cell line and was reverse transcribed to cDNA by the outer primers of WT1 and MDR1 respectively. The cDNA of WT1 and MDR1 were purified and digested by Bam H Ⅰ and Bgl Ⅱ , and then the two fragments were ligated to form the recombinant fragment WT1 + MDR1. The outer forward primer of WT1 and outer reverse primer of MDR1 were used to amplify the recombinant fragment WT1 + MDR1. The PCR product was purified and cloned into pMD18-T vector, and then transferred into E. coli DH-5α. A new kind of WT1-MDRl-contained standard plasmid was obtained from the positive colony. The recombinant plasmid was verified by digestion with restriction enzyme and PCR amplification. A multiplex real time quantitative PCR method was set up with FAM-labeled MDR1 probe and VIC-labeled WT1 probe in one reaction tube. The WT1 and MDR1 gene expression was detected in forty-seven AL patients and thirty-two controls by this method. Seven patients were followed-up to elucidate the relationship between the gene expression levels and clinical prognosis. Results The recombinant plasmid was confirmed by EcoR1 digestion and PCR amplification. The multiplex real time quantitative PCR technique could reach the sensitivity of WT1 and MDR1 gene up to 102 copy/μl. The standard curve slopes were 0. 999 and 0. 998. The WT1 [ 37 000( 163-6 370 000 )copies/μg RNA ] and MDR1 [ 76 200( 179-18 000 000 )copies/μg RNA ]expression levels of AL patients were significantly higher as compared to the controls [ 258( 0-643 ) copies/μg RNA and 333( 0-779 )copies/μg RNA ]( Z= 6. 755,6. 736, P ＜ 0. 01 ). Following up seven patients with similar regimen of chemotherapy, the WT1 and MDR1 expression correlated to the clinical course. Three AL patients with WT1 and MDR1 expression levels (2 170 and 86 900, 1 130 and 5 860, 1 170 and 586 copies/μg RNA )significantly decreased after chemotherapy and kept in the low range ( 370 and 560,138 and 980, 150 and 690 copies/μg RNA ), and had a favorable outcome. Three AL patients with WT1 and MDR1 expression levels ( 1 600 and 11 800, 24 800 and 968, 48 200 and 1 100 000 copies/μg RNA )decreased after initial chemotherapy, but increased significantly afterwards (20 314 and 25 660,184 364 and 31 530, 15 680 and 878 000 copies/μg RNA ),and suffered clinical relapse. One patient with high WT1 and MDR1 expression levels ( from 81 600 and 1 200 000 copies/μg RNA to 124 100 and 7 632 400 copies/μg RNA )showed the persistence of disease. Conclusions A multiplex real time quantitative PCR method to detect WT1 and MDR1 gene simultaneously is constructed successfully. The expression of WT1 and MDR1 may provide useful information for AL patients prognosis.

Association of the expressions of glomerular nephrin, vascular endothelial growth factor and its receptor with proteinuria in preeclampsia rats / 中华肾脏病杂志

Objective To investigate the association of the expressions of glomerular nephrin, vascular endothelial growth factor (VEGF) and its receptor (VEGFR) with proteinuria in preeclampsia rats. Methods A rat model of preeclampsia was developed by inhibitor of nitric oxide synthase (L-NAME). The systolic blood pressure (SBP) and 24 h urine protein were compared among the normal female group (n=6), the normal pregnant group (n=8), nonpregnant control group (n=6) and preeclampsia group(n=8). The kidney biopsies of each group were observed by light and electron microscopy. The glomerular nephrin was detected by Western blotting and real-time PCR. Immunofluorescence was used to detect the expression of WT1. The level of glomerular VEGF and VEGFR (Flt-1 and Flk-1) were evaluated by Western blotting. Results The level of glomerular nephrin protein in the rats with preeclampsia (0.0726±0.0074) was significantly lower compared with normal female group (0.3795±0.0509), normal pregnant group (0.2361±0.0437) and nonpregnant control group (0.7265±0.0503) (P＜0.01, respectively), while the levels of nephrin mRNA were not significantly different among 4 groups. The expression of WT1 was not significantly different among 4 groups as well. The level of glomerular VEGF in preeclampsia group (1.5429±0.0898) was significantly higher compared with normal female group (1.1870±0.1160), normal pregnant group (1.3741 ±0.1165) and nonpregnant control group (1.0155±0.0742)(P＜0.01,respectively). VEGFR (Flt-1 and Flk-1) was also significantly higher in preeclampsia rats compared with other control groups (P＜0.05, respectively). Conclusions In preeclampsia rats, nephrin is decreased significantly and the glomerular VEGF-VEGFR is increased significantly compared with the other control groups. The abnormal expression of nephrin and VEGF-VEGFR may be involved in the preeclampsia proteinuria. The underlying mechanism of this phenomenon needs further research.

protective effect of Enalapril and weight reduction on podocyte lesions of obesity-related gLomerulop-athy rats / 中国医师杂志

Objective To investigate the expression of WT1 in pedecyte of obesity- related glomerulopathy (ORG) rats and the mechanism of enalapril and weight reduction-induced renal protection. Methods After the ORG model was established by high lipid forage for 24 weeks, the rata were divided into control rats (group A), ORG rats (group B), enalapril-treated ORG rats (group C), ORG rats with weight reduction (group D) and enalapril -treated ORG rats with weight reduction (group E). At the 8th week, 24 hour urine albumen (24hUA1b) was assayed, and the pathological changes of kidney were detected by optics microscopy and transmission electronic microscopy. Immunohistochemistry was used to detect the expression of WT1, a marker of pedocyte injury. Results In ORG rats, pedocyte number and density were declined remarkably compared with group A (respectively, P<0.01), and 24 hour UA1b and obvious kidney damage were sig- nificantly higher than those of group A (respectively, P<0.01 ). After treatment, pedocyte number and density in group (C, D, E) were significantly increased compared with group B (respectively, P<0.05, P<0.01). Meanwhile, 24honr UA1b was reduced and kidney dam- age was alleviated ( respectively, P <0. 01 ), and therapeutic alliance effect in group E outweighed than that in group C and D. Conclusion Changes of pedocyte in ORG correlated with degree of proteinuria and renal function impairment. Enalapril and weight reduction can re- strain the expression of WT1 in ORG, which can reduce proteinuria and lessen kidney damage.

Two Cases of Isolated Diffuse Mesangial Sclerosis with WT1 Mutations

Here we report two cases of isolated diffuse mesangial sclerosis (IDMS) with early onset end-stage renal failure. These female patients did not show abnormalities of the gonads or external genitalia. Direct sequencing of WT1 PCR products from genomic DNA identified WT1 mutations in exons 8 (366 Arg>His) and 9 (396 Asp>Tyr). These mutations have been reported previously in association with Denys-Drash syndrome (DDS) with early onset renal failure. Therefore we suggest that, at least in part, IDMS is a variant of DDS and that investigations for the WT1 mutations should be performed in IDMS patients. In cases with identified WT1 mutations, the same attention to tumor development should be required as in DDS patients, and karyotyping and serial abdominal ultrasonograms to evaluate the gonads and kidney are warranted.