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Altres ajuts: Asociación Española Contra el Cáncer; Asociación de Afectados de Neurofibromatosis; ACNefi Altres ajuts: RTICC/RD12/0036/008 We wanted to implement an NGS strategy to globally analyze hereditary cancer with diagnostic quality while retaining the same degree of understanding and control we had in pre-NGS strategies. To do this, we developed the I2HCP panel, a custom bait library covering 122 hereditary cancer genes. We improved bait design, tested different NGS platforms and created a clinically driven custom data analysis pipeline. The I2HCP panel was developed using a training set of hereditary colorectal cancer, hereditary breast and ovarian cancer and neurofibromatosis patients and reached an accuracy, analytical sensitivity and specificity greater than 99%, which was maintained in a validation set. I2HCP changed our diagnostic approach, involving clinicians and a genetic diagnostics team from panel design to reporting. The new strategy improved diagnostic sensitivity, solved uncertain clinical diagnoses and identified mutations in new genes. We assessed the genetic variation in the complete set of hereditary cancer genes, revealing a complex variation landscape that coexists with the disease-causing mutation. We developed, validated and implemented a custom NGS-based strategy for hereditary cancer diagnostics that improved our previous workflows. Additionally, the existence of a rich genetic variation in hereditary cancer genes favors the use of this panel to investigate their role in cancer risk.

Wilms' tumor suppressor gene (WT1) en codes a tran scription factor required for nor mal development of the genitourinary system. Germline WT1 mutations have been described in a wide spectrum of pathological conditions, including kidney diseases, genital abnormalities and Wilms' tumor. Here we re port a 4-year-old male patient who presented with bilateral cryptorchidism, Wilms' tumor, nephroblastomatosis and renal failure with out nephrotic proteinuria. Sequence analysis of the WT1 gene demonstrated a constitutional heterozygous non sense mutation in exon 7, which leads to a truncation of the WT1 protein at the zinc-finger 1. In the DNA of the tumor, we ob served the same mutation in homo/hemizygosity. Given the requirement of WT1 for nor mal development, the WT1 mutation is likely to be responsible for the nephroblastomatosis and, in con sequence, for the severe renal failure ob served in our patient. This finding ex tends the spectrum of kidney diseases related to WT1 mutations and points to the need to screen for this gene in children with genitourinary abnormalities and Wilms' tumor be cause of the associated risk of nephroblastomatosis and renal failure in those carrying WT1 mutations.

Background and objectives The increasing number of podocyte-expressed genes implicated in steroid-resistant nephrotic syndrome (SRNS), the phenotypic variability, and the uncharacterized relative frequency of mutations in these genes in pediatric and adult patients with SRNS complicate their routine genetic analysis. Our aim was to compile the clinical and genetic data of eight podocyte genes analyzed in 110 cases (125 patients) with SRNS (ranging from congenital to adult onset) to provide a genetic testing approach. Design, setting, participants, & measurements Mutation analysis was performed by sequencing the NPHS1, NPHS2, TRPC6, CD2AP, PLCE1, INF2, WT1 (exons 8 and 9), and ACTN4 (exons 1 to 10) genes. Results We identified causing mutations in 34% (37/110) of SRNS patients, representing 67% (16/24) familial aid 25% (21/86) sporadic cases. Mutations were detected in 100% of congenital-onset, 57% of infantile-onset, 24 and 36% of early and late childhood-onset, 25% of adolescent-onset, and 14% of adult-onset patients. The most frequently mutated gene was NPHS1 in congenital onset and NPHS2 in the other groups. A partial remission was observed in 7 of 26 mutation carriers treated with immunosuppressive agents and/or angiotensin-converting enzyme inhibitors. Patients with NPHS1 mutations showed a faster progression to ESRD than patients with NPHS2 mutations. None of these mutation carriers relapsed after kidney transplantation. Conclusions We propose a genetic testing algorithm for SRNS based on the age at onset and the familial/sporadic status. Mutation analysis of specific podocyte-genes has a clinical value in all age groups, especially in children. Clin J Ant Soc Nephrol 6: 1139-1148, 2011. doi: 10.2215/CJN.05260610

Fabry disease is an X-linked recessive inborn error of glycosphingolipid metabolism caused by the deficient activity of the lysosomal enzyme, alpha-galactosidase A. Enzyme replacement therapy (ERT) for this disorder has been available in Europe since 2001. However, its effect on advanced renal failure remains controversial. We report the case of a patient whose decline in renal function was reduced by the administration of ERT (agalsidase-alpha). This reduction was more pronounced after doubling the dose of the enzyme. The rate of deterioration of eGFR went from 6.3 ml/min/year prior to the start of ERT (0.2 mg/kg) to 2 ml/min/year (0.4 mg/kg). To our knowledge, this is the first reported case of a patient with moderately impaired renal function treated with high doses of ERT and follow-up of 6 years. The data shown here suggest that ERT may have a very positive impact on renal function even in advanced stages. The role of proteinuria and its control seem to have a clear responsibility for this favorable outcome.

Altres ajuts: Fundación Renal Iñigo Álvarez de Toledo (FRIAT) Genetic diagnosis of steroid-resistant nephrotic syndrome (SRNS) using Sanger sequencing is complicated by the high genetic heterogeneity and phenotypic variability of this disease. We aimed to improve the genetic diagnosis of SRNS by simultaneously sequencing 26 glomerular genes using massive parallel sequencing and to study whether mutations in multiple genes increase disease severity. High-throughput mutation analysis was performed in 50 SRNS and/or focal segmental glomerulosclerosis (FSGS) patients, a validation cohort of 25 patients with known pathogenic mutations, and a discovery cohort of 25 uncharacterized patients with probable genetic etiology. In the validation cohort, we identified the 42 previously known pathogenic mutations across NPHS1, NPHS2, WT1, TRPC6, and INF2 genes. In the discovery cohort, disease-causing mutations in SRNS/FSGS genes were found in nine patients. We detected three patients with mutations in an SRNS/FSGS gene and COL4A3. Two of them were familial cases and presented a more severe phenotype than family members with mutation in only one gene. In conclusion, our results show that massive parallel sequencing is feasible and robust for genetic diagnosis of SRNS/FSGS. Our results indicate that patients carrying mutations in an SRNS/FSGS gene and also in COL4A3 gene have increased disease severity.

Background and objectives Single nucleotide polymorphisms (SNPs) within HLA complex class II HLA-DQ alpha-chain 1 (HLA-DQA1) and M-type phospholipase A2 receptor (PLA2R1) genes were identified as strong risk factors for idiopathic membranous nephropathy (IMN) development in a recent genome-wide association study. Copy number variants (CNVs) within the Fc gamma receptor III (FCGR3) locus have been associated with several autoimmune diseases, but their role in IMN has not been studied. This study aimed to validate the association of HLA-DQA1 and PLA2R1 risk alleles with IMN in a Spanish cohort, test the putative association of FCGR3A and FCGR3B CNVs with IMN, and assess the use of these genetic factors to predict the clinical outcome of the disease. Design, settings, participants, & measurements A Spanish cohort of 89 IMN patients and 286 matched controls without nephropathy was recruited between October of 2009 and July of 2012. Case-control studies for SNPs within HLA-DQA1 (rs2187668) and PLA2R1 (rs4664308) genes and CNVs for FCGR3A and FCGR3B genes were performed. The contribution of these polymorphisms to predict clinical outcome and renal function decline was analyzed. Results This study validated the association of these HLA-DQA1 and PLA2R1 SNPs with IMN in a Spanish cohort and its increased risk when combining both risk genotypes. No significant association was found between FCGR3 CNVs and IMN. These results revealed that HLA-DQA1 and PLA2R1 genotype combination adjusted for baseline proteinuria strongly predicted response to immunosuppressive therapy. HLA-DQA1 genotype adjusted for proteinuria was also linked with renal function decline. Conclusion This study confirms that HLA-DQA1 and PLA2R1 genotypes are risk factors for IMN, whereas no association was identified for FCGR3 CNVs. This study provides, for the first time, evidence of the contribution of these HLA-DQA1 and PLA2R1 polymorphisms in predicting IMN response to immunosuppressors and disease progression. Future studies are needed to validate and identify prognostic markers.

Background and objectives To date, very few cases with adult-onset focal segmental glomerulosclerosis (FSGS) carrying NPHS2 variants have been described, all of them being compound heterozygous for the p.R229Q variant and one pathogenic mutation. Design, setting, participants, & measurements Mutation analysis was performed in 148 unrelated Spanish patients, of whom 50 presented with FSGS after 18 years of age. Pathogenicity of amino acid substitutions was evaluated through an in silico scoring system. Haplotype analysis was carried out using NPHS2 single nucleotide polymorphism and microsatellite markers. Results Compound heterozygous or homozygous NPHS2 pathogenic mutations were identified in seven childhood-onset steroid-resistant nephrotic syndrome (SRNS) cases. Six additional cases with late childhood- and adult-onset SRNS were compound heterozygotes for p.R229Q and one pathogenic mutation, mostly p.A284V. p.R229Q was more frequent among SRNS cases relative to controls (odds ratio = 2.65; P = 0.02). Significantly higher age at onset of the disease and slower progression to ESRD were found in patients with one pathogenic mutation plus the p.R229Q variant in respect to patients with two NPHS2 pathogenic mutations. Conclusions NPHS2 analysis has a clinical value in both childhood- and adult-onset SRNS patients. For adult-onset patients, the first step should be screening for p.R229Q and, if positive, for p.A284V. These alleles are present in conserved haplotypes, suggesting a common origin for these substitutions. Patients carrying this specific NPHS2 allele combination did not respond to corticoids or immunosuppressors and showed FSGS, average 8-year progression to ESRD, and low risk for recurrence of FSGS after kidney transplant. Clin J Am Soc Nephrol 6: 344-354, 2011. doi: 10.2215/CJN.03770410

Background. Mutations in the TRPC6 gene have been reported in six families with adult-onset (17-57 years) autosomal dominant focal segmental glomerulosclerosis (FSGS). Electrophysiology studies confirmed augmented calcium influx only in three of these six TRPC6 mutations. To date, the role of TRPC6 in childhood and adulthood non-familial forms is unknown. Methods. TRPC6 mutation analysis was performed by direct sequencing in 130 Spanish patients from 115 unrelated families with FSGS. An in silico scoring matrix was developed to evaluate the pathogenicity of amino acid substitutions, by using the bio-physical and bio-chemical differences between wild-type and mutant amino acid, the evolutionary conservation of the amino acid residue in orthologues, homologues and defined domains, with the addition of contextual information. Results. Three new missense substitutions were identified in two clinically non-familial cases and in one familial case. The analysis by means of this scoring system allowed us to classify these variants as likely pathogenic mutations. One of them was detected in a female patient with unusual clinical features: mesangial proliferative FSGS in childhood (7 years) and partial response to immunosupressive therapy (CsA + MMF). Asymptomatic carriers of this likely mutation were found within her family. Conclusions. We describe for the first time TRPC6 mutations in children and adults with non-familial FSGS. It seems that TRPC6 is a gene with a very variable penetrance that may contribute to glomerular diseases in a multi-hit setting.

Background: Primary focal segmental glomerulosclerosis (FSGS) is a glomerular disease that frequently does not respond to treatment and progresses to kidney failure. FSGS can be of either genetic origin, caused by mutations in slit diaphragm proteins, such as podocin, or idiopathic origin of unknown cause. Study Design: Case series. Setting & Participants: Children with FSGS (aged 3-18 years); 15 with idiopathic and 11 with genetic forms of FSGS. Predictor: Genetic versus idiopathic forms. Outcomes & Measurements: Differentially expressed proteins in the plasma proteome, detected using 2-dimensional electrophoresis and identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, Western blot, and liquid chromatography electron spray ionization tandem mass spectrometry for fragmentation and identification of the peptides. Results: We found 3 very low-molecular-mass (9.2, 6.9, and 4.7 kDa; isoelectric point, 5.7) spots that were present in pooled samples from patients with genetic FSGS, but missing in patients with idiopathic FSGS and healthy individuals. Spots were identified using mass spectrometry as fragments of albumin, 2 of them apparently containing peptides from both C- and N-terminal parts of the whole protein. Proteomic analyses were carried out on all genetic patients individually; of these, 10 of 11 patients had >= 1 albumin fragment detected in the pool. We did not find an evident relationship between type of mutation or clinical status of patients and albumin fragments observed. Limitations: Very low-molecular-weight albumin fragments also can be produced by other diseases. Conclusions: We describe for the first time the presence of very low-molecular-mass albumin fragments in plasma of patients with FSGS with podocyte protein mutations that are absent in patients with idiopathic FSGS or healthy individuals. Additional studies are necessary to determine whether these fragments could be potential biomarkers to distinguish between genetic and idiopathic forms of FSGS. Am J Kidney Dis 54:871-880. (C) 2009 by the National Kidney Foundation, Inc.

Introduccion El 20 % de los pacientes con sindrome nefrotico (SN) son corticorresistentes (SNCR), con una progresion hacia insuficiencia renal cronica en aproximadamente el 50 % de los casos. El SNCR es una enfermedad geneticamente heterogenea ya que puede estar causada por mutaciones en distintos genes (NPHS1, NPHS2, ACTN4,...). Se realiza estudio molecular amplio (de varios genes) del SNCR. Los resultados provienen de un cribaje mutacional del gen NPHS2 en poblacion espanola con SNCR. Material y metodos Analisis mutacional del gen NPHS2, mediante la secuenciacion directa de sus 8 exones, en 50 pacientes con SNCR (47 biopsiados: GESF). De los pacientes estudiados, 38 son esporadicos (86 %) y 6 son familiares, hermanos (14 %). Resultados De 11 casos hemos detectado 9 mutaciones diferentes, de las cuales la mutacion 790 G > C (G245Q), situada en el exon 6, y la mutacion 971-987 (del exon 8) no han sido descritas anteriormente. Identificamos 4 pacientes heterocigotos compuestos, 3 en los que unicamente hemos detectado una mutacion en heterocigosis, y 4 con mutacion en heterocigosis y simultaneamente portadores de la variante no conservativa R229Q. La tasa de deteccion de mutaciones en el SNCR familiar es del 83 % (5/6 familias con SNCR). En cambio, en el SNCR esporadico es 6 veces menor, un 16 % (6/38). La mutacion de cambio de sentido A284V (exon 7) en heterocigosis, que se presenta siempre conjuntamente con la variante R229Q, es la mas frecuente y aparece en pacientes con una aparicion tardia del sindrome (media: 20, DE: 10,4), una clara resistencia a los corticoids y biopsia de hialinosis segmentaria y focal. Los pacientes con mutacion compuesta y en los que solo hay mutacion en heterocigosis, el inicio de la enfermedad es temprano. Los heterocigotos, probablemente tengan otra mutacion en otra region del gen (promotor) que no hemos analizado, o bien, presenten otra mutacion en algun otro gen. Conclusion Con estos resultados preliminares podemos decir que los pacientes con SNCR presentan mutaciones en el gen NPHS2 con una baja prevalencia. Los casos familiares con inicio precoz del sindrome tienen un elevado riesgo de ser portadores de mutaciones NPHS2. Estaria indicado realizar un analisis genetico de NPHS2 a los pacientes que no respondan inicialmente al tratamiento con esteroides, para la prevencion de una posible iatrogenia innecesaria.

Background Alport syndrome (AS) is a genetically heterogeneous hereditary renal disease. X-Linked AS (XLAS) is responsible for 80% to 85% of familial cases and is caused by mutations in the COL4A5 collagen gene. To date, indirect molecular diagnosis for XLAS is not well defined, and mutation screening of the COL4A5 gene is time consuming and complicated because of its large size and high allelic heterogeneity. Our aim is to facilitate XLAS genetic testing. Methods For linkage analysis, we tested the applicability of 4 microsatellite markers defining a 1.2-megabase region flanking the COL4A5 gene. For mutation screening of the COL4A5 gene, we describe a new strategy based on direct sequencing of hair root COL4A5 messenger RNA (mRNA). Results Three microsatellite markers proved accurate ( DXS1120 , DXS6802 , and DXS1210 ) and 1 was discarded ( DXS6797 ) because it was difficult to interpret. The mutation screening method provides results in 4 days, and when applied to 29 patients suspected of having XLAS, it identified mutations in 76% (22 of 29 patients). This study correlates COL4A5 mutations with effects at the mRNA level and suggests that mutations affecting mRNA splicing of the COL4A5 gene (41%; 9 of 22 patients) are more common than previously described. Many splicing mutations did not alter the canonical 5′ and 3′ splice sites. Conclusions A more reliable linkage analysis and a simple, fast, and efficient mutation screening are now available for the genetic testing of patients with XLAS.

This study was funded by the Spanish Government, Instituto de Salud Carlos III (ISCIII), through the CIBER CRP-TB and the FIS 011/01702 grants to PJC, and by Manresana de Micobacteriologia, s.l. Additional support came from IMPPC core funding from the Generalitat de Catalunya to LS. JV, GR, SS, were funded by grant ADE10/00026 from ISCIII. JV was also co-funded by ISIS contract II11/00014 from ISCIII. IC is supported by the Spanish Ministerio de Economia y Competitividad (MINECO) through a Ramón y Cajal contract RYC-2012-10627 and grant SAF2013-43521-R. E.J. was funded by Instituto de Salud Carlos III-PI1001438 and the European Regional Development Fund (FEDER), and CV by Miguel Servet Contract CP13/00174. We present here the draft genome sequences of two Mycobacterium setense strains. One of them corresponds to the M. setense type strain DSM-45070, originally isolated from a patient with a posttraumatic chronic skin abscess. The other one corresponds to the nonpathogenic M. setense strain Manresensis, isolated from the Cardener River crossing Manresa, Catalonia, Spain. A comparative genomic analysis shows a smaller genome size and fewer genes in M. setense strain Manresensis relative to those of the type strain, and it shows the genome segments unique to each strain.