Centro Interdipartimentale di Biotecnologie Molecolari "Guido Tarone"
Alfredo Brusco - PI
2023 to date Full Professor in Medical Genetics, University of Turin
2016-2023 Associate Professor in Medical Genetics, University of Turin
2000-2016 Assistant Professor in Medical Genetics, University of Turin
2000 to date Head biologist Città della Salute e della Scienza University Hospital, Turin
1998 to date Group leader of the Medical Genetics and Rare Diseases laboratory
- Lisa Pavinato, post-doc
- Slavica Trajkova, post-doc
- Simona Cardaropoli, Research assistant
- Verdiana Pullano, PhD student
- Silvia Carestiato, PhD student
- Chiara Giovenino, Trainee in Medical genetics
- Serena Rizzo, Trainee in Medical genetics
- Chiara Leso fellowship student
Research activity
Neurodevelopmental disorders (NDDs) are a broad spectrum of conditions that include autism spectrum disorders (ASD), intellectual disability, epilepsy, and ADHD. NDDs have a strong genetic component, but our knowledge about the molecular mechanisms involved in their onset is still limited.
Our research is focused on studying Mendelian forms of NDDs at several levels (Figure 1).
We are interested in improving the yield of genetic tests by providing implemented pipelines of exome sequencing (ES) analysis. The interpretation of genetic variants is often hindered by the lack of functional tests, which allow us to sustain the pathogenicity of variants of uncertain significance. We are thus fascinated by studying complex genetic mechanisms causing genetic diseases, such as mobile element insertions, complex splicing anomalies, uncommon imprinting pathogenic variants, and TADopaties causing enhancer adoption. We are also particularly interested in the role of non-random X chromosome inactivation (XCI) in NDDs, which can disclose X-linked forms. Genetic NDDs frequently present with overlapping clinical features and inconclusive or ambiguous genetic findings, which can confound accurate diagnosis and clinical management. An increasing number of genetic syndromes have been shown to have unique genomic DNA methylation patterns (called “episignatures”). We are working to define novel episignatures and apply these methods in diagnostics.
The number of NDD-associated genes is still limited; for instance, more than 1,000 genes are expected to be related to ASDs, but only 150 are presently known. One major aim of our laboratory is to define novel NDD genes by exploiting a large cohort of NDD cases collected and sequenced in the last years (NeuroWES project). This work has already allowed us to find more than 10 novel genes, among which CAPRIN1, whose haploinsufficiency causes NDD. The work done on this gene exemplifies our interest in the study of NDDs. We generated CAPRIN1+/− human induced pluripotent stem cells (hiPSCs) via CRISPR–Cas9 mutagenesis and differentiated them into neuronal progenitor cells and cortical neurons. CAPRIN1 loss caused reduced neuronal processes, overall disruption of the neuronal organization, and increased neuronal degeneration. We also observed an alteration of mRNA translation in CAPRIN1+/− neurons, compatible with its suggested function as a translational inhibitor. As suggested above, our work is also interested in finding new diagnostic tools, and for CAPRIN1 patients we are also working on the generation of a specific methylation profile (Figure 2).
Understanding gene function in neuronal models is one of our main targets. We are presently working on several other candidate and known NDD genes/regions, such as the duplication 15q11.2, one of the most common genetic causes of ASD. In this case, we are exploiting Micro Electrode Arrays to test for drugs potentially effective on epilepsy. Finally, we are particularly interested in modifier genes, which can be a target of disease-specific therapies. In this topic, we are studying TANGO2-autosomal recessive disease, where we have identified phenotypically discordant siblings with loss of function variants in the gene. The study of neuron-induced hiPSCs by morphological, functional, and transcriptome analysis is shedding light on the role of compensatory genetic mechanisms.
As an innovative method to study NDDs in vitro we are using Dental Pulp Stem Cells (DPSC), pluripotent mesenchymal stem cells that can be differentiated into neurons. These cells can be easily collected from deciduous teeth and used in vitro in functional experiments
We plan to use short and long-read genome sequencing and transcriptomics to search for causative variants in NDD cases that are negative at exome analysis. We will use in vitro neuronal and organoid models to study the pathogenic mechanisms of novel NDD genes. We will also develop novel episignature profiles that may help with diagnosis in NDDs and neurologic disorders.
Coordinator of the multicentric project: “Multiomic strategies to implement the diagnostic workflow of rare diseases”. Ministero della Salute, PNRR-MR1-2022-12376067. 2023-2024.
Co-Coordinator TANGO2 foundation project: “Understanding TANGO2 pathogenic mechanisms in hiPSCs-derived neurons”. Giugno 2022-maggio 2023.
Partner PRIN 2020: “Unveiling the hidden side of NEUrodevelopmental DIsorder Genetics (NEUDIG): a multidisciplinary pathway to new molecular diagnoses by integrating genomic, transcriptomic, and functional analyses”.
Coordinator Genetica e Farmacogenomica, Progetto di Eccellenza Dipartimento Scienze Mediche, Università di Torino 2018-2022
Partner PRIN Project 2017: “Multidisciplinary approach to study protocadherin 19: from neuronal function to the "cellular interference" pathogenic mechanism”. 20172C9HLW. 2019-2022
Principal investigator of a Telethon multicenter project GGP14225: “Translating molecular pathology into a therapeutic strategy in SCA38, a newly identified form of spinocerebellar ataxia”. 2015-2019.
Melo, U.S., Jatzlau, J., Prada-Medina, et al. Enhancer hijacking at the ARHGAP36 locus is associated with connective tissue to bone transformation. (2023) Nature Communications, 14 (1), DOI: 10.1038/s41467- 023-37585-8
Pavinato, L., Stanic, J., Barzasi, M., … and Brusco, A. Missense variants in RPH3A cause defects in excitatory synaptic function and are associated with a clinically variable neurodevelopmental disorder. (2023) Genet Med. Nov;25(11):100922, DOI: 10.1016/j. gim.2023.100922.
Pavinato, L., Delle Vedove, A., Carli, D., … and Brusco, A. CAPRIN1 haploinsuficiency causes a neurodevelopmental disorder with language impairment, ADHD and ASD (2023) Brain, 146 (2), pp. 534-548. DOI: 10.1093/brain/awac278
Ferrero, E., Di Gregorio, E., Ferrero, … and Brusco, A. Spinocerebellar ataxia 38: structure–function analysis shows ELOVL5 G230V is proteotoxic, conformationally altered and a mutational hotspot (2023) (2023) Hum Genet. Aug;142(8):1055-1076. DOI: 10.1007/s00439- 023-02572-y
Giovenino, C., Trajkova, S., Pavinato, L., … and Brusco, A. Skewed X-chromosome inactivation in unsolved neurodevelopmental disease cases can guide re-evaluation For X-linked genes (2023) (2023) Eur J Hum Genet. Nov;31(11):1228-1236. DOI: 10.1038/s41431- 023-01324-w
Pavinato, L., Villamor-Payà, M., Sanchiz-Calvo, … and Brusco, A. Functional analysis of TLK2 variants and their proximal interactomes implicates impaired kinase activity and chromatin maintenance defects in their pathogenesis (2022) Journal of Medical Genetics, 59 (2), pp. 170-179. DOI: 10.1136/jmedgenet-2020-107281
Fu, J.M., Satterstrom, F.K., Peng, M., et al., The Autism Sequencing Consortium (ASC), Broad Institute Center for Common Disease Genomics (Broad-CCDG), iPSYCH-BROAD Consortium. Rare coding variation provides insight into the genetic architecture and phenotypic context of autism (2022) Nat Genet. Sep;54(9):1320-1331, DOI: 10.1038/s41588-022-01104-0
Satterstrom, F.K., Kosmicki, J.A., Wang, J., et al., Autism Sequencing Consortium, iPSYCH-Broad Consortium. Large-Scale Exome Sequencing Study Implicates Both Developmental and Functional Changes in the Neurobiology of Autism (2020) Cell, 180 (3), pp. 568-584.e23. DOI: 10.1016/j.cell.2019.12.036
Giorgio, E., Lorenzati, M., Di Val Cervo, … and Brusco, A. Allele-specific silencing as treatment for gene duplication disorders: Proof-of-principle in autosomal dominant leukodystrophy (2019) Brain, 142 (7), pp. 1905- 1920. DOI: 10.1093/brain/awz139
Giorgio, E., Robyr, D., Spielmann, … and Brusco, A. A large genomic deletion leads to enhancer adoption by the lamin B1 gene: A second path to autosomal dominant adult-onset demyelinating leukodystrophy (ADLD), (2014) Human Molecular Genetics, 24 (11), pp. 3143- 3154. DOI: 10.1093/hmg/ddv065
