@article {818, title = {A genomic strategy for precision medicine in rare diseases: integrating customized algorithms into clinical practice.}, journal = {J Transl Med}, volume = {23}, year = {2025}, month = {2025 Jan 20}, pages = {86}, abstract = {

BACKGROUND: Despite the use of Next-Generation Sequencing (NGS) as the gold standard for the diagnosis of rare diseases, its clinical implementation has been challenging, limiting the cost-effectiveness of NGS and the understanding, control and safety essential for decision-making in clinical applications. Here, we describe a personalized NGS-based strategy integrating precision medicine into a public healthcare system and its implementation in the routine diagnosis process during a five-year pilot program.

METHODS: Our approach involved customized probe designs, the generation of virtual panels and the development of a personalized medicine module (PMM) for variant prioritization. This strategy was applied to 6500 individuals including 6267 index patients and 233 NGS-based carrier screenings.

RESULTS: Causative variants were identified in 2061 index patients (average 32.9\%, ranging from 12 to 62\% by condition). Also, 131 autosomal-recessive cases could be partially genetically diagnosed. These results led to over 5000 additional studies including carrier, prenatal and preimplantational tests or pharmacological and gene therapy treatments.

CONCLUSION: This strategy has shown promising improvements in the diagnostic rate, facilitating timely diagnosis and gradually expanding our services portfolio for rare diseases. The steps taken towards the integration of clinical and genomic data are opening new possibilities for conducting both retrospective and prospective healthcare studies. Overall, this study represents a major milestone in the ongoing efforts to improve our understanding and clinical management of rare diseases, a crucial area of medical research and care.

}, keywords = {Algorithms, Female, Genomics, High-Throughput Nucleotide Sequencing, Humans, Precision Medicine, rare diseases}, issn = {1479-5876}, doi = {10.1186/s12967-025-06069-2}, author = {M{\'e}ndez-Vidal, Cristina and Bravo-Gil, Nereida and Perez-Florido, Javier and Marcos-Luque, Irene and Fern{\'a}ndez, Raquel M and Fernandez-Rueda, Jose Luis and Gonz{\'a}lez-del Pozo, Mar{\'\i}a and Mart{\'\i}n-S{\'a}nchez, Marta and Fern{\'a}ndez-Su{\'a}rez, Elena and Mena, Marcela and Carmona, Rosario and Dopazo, Joaquin and Borrego, Salud and Anti{\v n}olo, Guillermo} } @article {452, title = {Improving the management of Inherited Retinal Dystrophies by targeted sequencing of a population-specific gene panel.}, journal = {Sci Rep}, volume = {6}, year = {2016}, month = {2016 Apr 01}, pages = {23910}, abstract = {

Next-generation sequencing (NGS) has overcome important limitations to the molecular diagnosis of Inherited Retinal Dystrophies (IRD) such as the high clinical and genetic heterogeneity and the overlapping phenotypes. The purpose of this study was the identification of the genetic defect in 32 Spanish families with different forms of IRD. With that aim, we implemented a custom NGS panel comprising 64 IRD-associated genes in our population, and three disease-associated intronic regions. A total of 37 pathogenic mutations (14 novels) were found in 73\% of IRD patients ranging from 50\% for autosomal dominant cases, 75\% for syndromic cases, 83\% for autosomal recessive cases, and 100\% for X-linked cases. Additionally, unexpected phenotype-genotype correlations were found in 6 probands, which led to the refinement of their clinical diagnoses. Furthermore, intra- and interfamilial phenotypic variability was observed in two cases. Moreover, two cases unsuccessfully analysed by exome sequencing were resolved by applying this panel. Our results demonstrate that this hypothesis-free approach based on frequently mutated, population-specific loci is highly cost-efficient for the routine diagnosis of this heterogeneous condition and allows the unbiased analysis of a miscellaneous cohort. The molecular information found here has aid clinical diagnosis and has improved genetic counselling and patient management.

}, keywords = {Alleles, Computer Simulation, DNA Copy Number Variations, DNA Mutational Analysis, Eye Proteins, Gene Library, Genetic Association Studies, Genetic Heterogeneity, Genetic Therapy, High-Throughput Nucleotide Sequencing, Humans, mutation, Phenotype, Retinal Dystrophies}, issn = {2045-2322}, doi = {10.1038/srep23910}, author = {Bravo-Gil, Nereida and M{\'e}ndez-Vidal, Cristina and Romero-P{\'e}rez, Laura and Gonz{\'a}lez-del Pozo, Mar{\'\i}a and Rodr{\'\i}guez-de la R{\'u}a, Enrique and Dopazo, Joaquin and Borrego, Salud and Anti{\v n}olo, Guillermo} } @article {467, title = {Re-evaluation casts doubt on the pathogenicity of homozygous USH2A p.C759F.}, journal = {Am J Med Genet A}, volume = {167}, year = {2015}, month = {2015 Jul}, pages = {1597-600}, abstract = {

Mutations in USH2A are a common cause of Retinitis Pigmentosa (RP). Among the most frequently reported USH2A variants, c.2276G>T (p.C759F) has been found in both affected and healthy individuals. The pathogenicity of this variant remains controversial since it was detected in homozygosity in two healthy siblings of a Spanish family (S23), eleven years ago. The fact that these individuals remain asymptomatic today, prompted us to study the presence of other pathogenic variants in this family using targeted resequencing of 26 retinal genes in one of the affected individuals. This approach allowed us to identify one novel pathogenic homozygous mutation in exon 13 of PDE6B (c.1678C>T; p.R560C). This variant cosegregated with the disease and was absent in 200 control individuals. Remarkably, the identified variant in PDE6B corresponds to the mutation responsible of the retinal degeneration in the naturally occurring rd10 mutant mice. To our knowledge, this is the first report of the identification of the rd10 mice mutation in a RP family. These findings, together with a review of the literature, support the hypothesis that homozygous p.C759F mutations are not pathogenic and led us to exclude the implication of p.C759F in the RP of family S23. Our results indicate the need of re-evaluating all families genetically diagnosed with this mutation.

}, keywords = {Base Sequence, Cyclic Nucleotide Phosphodiesterases, Type 6, Extracellular Matrix Proteins, Gene Library, Humans, Molecular Sequence Data, Mutation, Missense, Pedigree, Retinitis pigmentosa, Sequence Analysis, DNA, Spain}, issn = {1552-4833}, doi = {10.1002/ajmg.a.37003}, author = {Pozo, Mar{\'\i}a Gonz{\'a}lez-Del and Bravo-Gil, Nereida and M{\'e}ndez-Vidal, Cristina and Montero-de-Espinosa, Ignacio and Mill{\'a}n, Jos{\'e} M and Dopazo, Joaquin and Borrego, Salud and Anti{\v n}olo, Guillermo} } @article {486, title = {Deciphering intrafamilial phenotypic variability by exome sequencing in a Bardet-Biedl family.}, journal = {Mol Genet Genomic Med}, volume = {2}, year = {2014}, month = {2014 Mar}, pages = {124-33}, abstract = {

Bardet-Biedl syndrome (BBS) is a model ciliopathy characterized by a wide range of clinical variability. The heterogeneity of this condition is reflected in the number of underlying gene defects and the epistatic interactions between the proteins encoded. BBS is generally inherited in an autosomal recessive trait. However, in some families, mutations across different loci interact to modulate the expressivity of the phenotype. In order to investigate the magnitude of epistasis in one BBS family with remarkable intrafamilial phenotypic variability, we designed an exome sequencing-based approach using SOLID 5500xl platform. This strategy allowed the reliable detection of the primary causal mutations in our family consisting of two novel compound heterozygous mutations in McKusick-Kaufman syndrome (MKKS) gene (p.D90G and p.V396F). Additionally, exome sequencing enabled the detection of one novel heterozygous NPHP4 variant which is predicted to activate a cryptic acceptor splice site and is only present in the most severely affected patient. Here, we provide an exome sequencing analysis of a BBS family and show the potential utility of this tool, in combination with network analysis, to detect disease-causing mutations and second-site modifiers. Our data demonstrate how next-generation sequencing (NGS) can facilitate the dissection of epistatic phenomena, and shed light on the genetic basis of phenotypic variability.

}, issn = {2324-9269}, doi = {10.1002/mgg3.50}, author = {Gonz{\'a}lez-del Pozo, Mar{\'\i}a and M{\'e}ndez-Vidal, Cristina and Santoyo-L{\'o}pez, Javier and Vela-Boza, Alicia and Bravo-Gil, Nereida and Rueda, Antonio and Garc{\'\i}a-Alonso, Luz and V{\'a}zquez-Marouschek, Carmen and Dopazo, Joaquin and Borrego, Salud and Anti{\v n}olo, Guillermo} } @article {489, title = {Exome sequencing reveals novel and recurrent mutations with clinical significance in inherited retinal dystrophies.}, journal = {PLoS One}, volume = {9}, year = {2014}, month = {2014}, pages = {e116176}, abstract = {

This study aimed to identify the underlying molecular genetic cause in four Spanish families clinically diagnosed of Retinitis Pigmentosa (RP), comprising one autosomal dominant RP (adRP), two autosomal recessive RP (arRP) and one with two possible modes of inheritance: arRP or X-Linked RP (XLRP). We performed whole exome sequencing (WES) using NimbleGen SeqCap EZ Exome V3 sample preparation kit and SOLID 5500xl platform. All variants passing filter criteria were validated by Sanger sequencing to confirm familial segregation and the absence in local control population. This strategy allowed the detection of: (i) one novel heterozygous splice-site deletion in RHO, c.937-2_944del, (ii) one rare homozygous mutation in C2orf71, c.1795T>C; p.Cys599Arg, not previously associated with the disease, (iii) two heterozygous null mutations in ABCA4, c.2041C>T; p.R681* and c.6088C>T; p.R2030*, and (iv) one mutation, c.2405-2406delAG; p.Glu802Glyfs*31 in the ORF15 of RPGR. The molecular findings for RHO and C2orf71 confirmed the initial diagnosis of adRP and arRP, respectively, while patients with the two ABCA4 mutations, both previously associated with Stargardt disease, presented symptoms of RP with early macular involvement. Finally, the X-Linked inheritance was confirmed for the family with the RPGR mutation. This latter finding allowed the inclusion of carrier sisters in our preimplantational genetic diagnosis program.

}, keywords = {Adolescent, Adult, Amino Acid Sequence, Base Sequence, Child, Chromosome Segregation, DNA Mutational Analysis, Exome, Family, Female, Humans, Inheritance Patterns, Male, Middle Aged, Molecular Sequence Data, mutation, Pedigree, Retinal Dystrophies, Rhodopsin}, issn = {1932-6203}, doi = {10.1371/journal.pone.0116176}, author = {Gonz{\'a}lez-del Pozo, Mar{\'\i}a and M{\'e}ndez-Vidal, Cristina and Bravo-Gil, Nereida and Vela-Boza, Alicia and Dopazo, Joaquin and Borrego, Salud and Anti{\v n}olo, Guillermo} } @article {490, title = {Novel RP1 mutations and a recurrent BBS1 variant explain the co-existence of two distinct retinal phenotypes in the same pedigree.}, journal = {BMC Genet}, volume = {15}, year = {2014}, month = {2014 Dec 14}, pages = {143}, abstract = {

BACKGROUND: Molecular diagnosis of Inherited Retinal Dystrophies (IRD) has long been challenging due to the extensive clinical and genetic heterogeneity present in this group of disorders. Here, we describe the clinical application of an integrated next-generation sequencing approach to determine the underlying genetic defects in a Spanish family with a provisional clinical diagnosis of autosomal recessive Retinitis Pigmentosa (arRP).

RESULTS: Exome sequencing of the index patient resulted in the identification of the homozygous BBS1 p.M390R mutation. Sanger sequencing of additional members of the family showed lack of co-segregation of the p.M390R variant in some individuals. Clinical reanalysis indicated co-ocurrence of two different phenotypes in the same family: Bardet-Biedl syndrome in the individual harboring the BBS1 mutation and non-syndromic arRP in extended family members. To identify possible causative mutations underlying arRP, we conducted disease-targeted gene sequencing using a panel of 26 IRD genes. The in-house custom panel was validated using 18 DNA samples known to harbor mutations in relevant genes. All variants were redetected, indicating a high mutation detection rate. This approach allowed the identification of two novel heterozygous null mutations in RP1 (c.4582_4585delATCA; p.I1528Vfs*10 and c.5962dupA; p.I1988Nfs*3) which co-segregated with the disease in arRP patients. Additionally, a mutational screening in 96 patients of our cohort with genetically unresolved IRD revealed the presence of the c.5962dupA mutation in one unrelated family.

CONCLUSIONS: The combination of molecular findings for RP1 and BBS1 genes through exome and gene panel sequencing enabled us to explain the co-existence of two different retinal phenotypes in a family. The identification of two novel variants in RP1 suggests that the use of panels containing the prevalent genes of a particular population, together with an optimized data analysis pipeline, is an efficient and cost-effective approach that can be reliably implemented into the routine diagnostic process of diverse inherited retinal disorders. Moreover, the identification of these novel variants in two unrelated families supports the relatively high prevalence of RP1 mutations in Spanish population and the role of private mutations for commonly mutated genes, while extending the mutational spectrum of RP1.

}, keywords = {Bardet-Biedl Syndrome, Base Sequence, Case-Control Studies, DNA Mutational Analysis, Eye Proteins, Genes, Recessive, Genetic Association Studies, Humans, Microsatellite Repeats, Microtubule-Associated Proteins, Mutation, Missense, Pedigree, Phenotype, Retina, Retinitis pigmentosa}, issn = {1471-2156}, doi = {10.1186/s12863-014-0143-2}, author = {M{\'e}ndez-Vidal, Cristina and Bravo-Gil, Nereida and Gonz{\'a}lez-del Pozo, Mar{\'\i}a and Vela-Boza, Alicia and Dopazo, Joaquin and Borrego, Salud and Anti{\v n}olo, Guillermo} }