Single cell studies have found an increasing number of brain disorders caused by mosaic genetic deletions that only affect a small portion of cells but show brain-wide symptoms. This suggests that mutant cells affect the development and function of the surrounding healthy cells. Mosaic genetic mutations are understudied because it is complex and difficult to model in animals. This proposal will use a novel mosaic mouse model to advance our understanding of how mosaic genetic mutations affect brain development in Tuberous sclerosis complex (TSC), a brain disorder associated with mosaic mutations in the TSC2 gene.
TSC patients show intellectual disability and carry cortical tubers, composed of disorganized neurons and glia in the cortex. Tuber cells are hypothesized to originate from small number of neurons carrying biallelic TSC2 inactivation embedded in a largely TSC2 heterozygous brain. A major challenge in modeling TSC is that TSC2 heterozygous animals show little symptoms and does not genetically mimic mosaic biallelic TSC2 loss. Due to the lack of appropriate animal models, the neural mechanism underlying intellectual disability and epilepsy is unknown, preventing the development of treatment to target these cells.
This project will use a novel technique called MADM (mosaic analysis of double marker) to induce homozygous, somatic TSC2 deletions in a cell type-specific manner. MADM allows in vivo Cre-dependent genetic manipulation and fluorescent labeling of wild-type, heterozygous, and homozygous TSC2 deletions in selected brain cells. We hypothesize that cortical cells with biallelic TSC2 loss become tuber cells, show abnormal neuronal activity and gene expression. This work will uncover a novel mechanism underlying mosaic brain disorders and shed light on the etiology and therapeutic interventions of other brain disorders caused by mosaic mutations.

Rett syndrome (RTT) is a complex neurodevelopmental disorder, caused in the majority of cases by mutation in the MECP2 gene. Many data, including our preliminary observations, point to a perturbation of brain cholesterol metabolism in RTT. Cholesterol is a multifaced molecule: it is an essential structural component of cell membranes, a precursor for many signaling molecules and one of the most important factors responsible for formation and functioning of synapses. In the adult brain, cholesterol is produced locally, predominantly by astrocytes, a cell type that, besides neurons, are involved in the disease.
Our research group has demonstrated that astrocytes lacking Mecp2 negatively impinge on neuronal maturation at the synaptic level. Indeed, RTT astrocytes affect synaptic formation and functioning by both the excessive secretion of toxic molecules and the reduced release of beneficial ones, among which we have identified cholesterol. Accordingly, we observed that cholesterol supplementation rescues synaptic alterations in RTT neurons.
By using cutting-edge mass spectrometry techniques, in combination with molecular assays, our project aims at deeply exploring cholesterol and its metabolites in the different brain regions of RTT animal models, to obtain an exhaustive description of cholesterol metabolism along the disease at spatial and single-cell level. Moreover, we will test for the first time the efficacy of a novel approach aimed at delivering cholesterol to the brain through a systemic administration of brain-permeable nanoparticles.
If successful, this study will provide a comprehensive overview of cholesterol abnormalities in RTT brain and the proof-of-concept of the therapeutic potential of cholesterol-based strategies.

Fragile X syndrome (FXS) is a common condition that affects how the brain works, leading to learning difficulties and problems with movement and memory. In people with FXS, there is a problem with a signalling system called Wnt, which helps cells communicate. Some research suggests that acting on the Wnt system could help treat FXS. We have discovered a protein called augurin, made by a gene called Ecrg4, that can change the way how the Wnt system works. Augurin is found in high levels in a part of the brain called the choroid plexus, which helps make cerebrospinal fluid. Our project has four main goals: – To see where augurin is found in the brain during development – To study how the brains of mice without the Ecrg4 gene develop. – To look at the molecular details of brain development in these mice. For this project we will work in close collaboration with experts in brain development in Mumbai, India. Our research will help us understand more about how the brain develops and could lead to new treatments for FXS and other brain disorders.

Creatine Transporter Deficiency (CTD) is a rare genetic disorder caused by SLC6A8 mutations, leading to low brain creatine (Cr) and severe neurological symptoms, including learning disabilities, movement issues, autism-like behaviours, and seizures. Current treatments are ineffective, requiring lifelong care. Our previous research showed partial improvement in CTD mice using gene replacement but revealed risks from excessive protein levels. We aim to develop a safer gene therapy by introducing a modified SLC6A8 gene to restore brain function without harm. Testing in CTD mice will assess its ability to normalize brain Cr, enhance neural function, improve cognition and behaviour, and reduce seizures. We will also explore its potential when started later in disease progression. This research seeks to alleviate CTD symptoms and establish a foundation for clinical trials, offering new hope to affected patients and families.

This study aims to investigate the involvement of a potentially important gene for Prader-Willi syndrome, called DGKk (diacylglycerol kinase kappa), and to explore its potential as a disease biomarker. Prader-Willi syndrome (PWS) has been associated with the loss of a region of chromosome 15 expressing small RNA molecules called SNORD. Although the function of these SNORD116 molecules is not fully understood, new data suggest that they regulate DGKk expression, an essential enzyme for neuronal signaling, metabolism and behavioral regulation. Preliminary data suggest that DGKk is abnormally expressed in PWS models, providing a possible mechanism for SNORD116 loss. However, the extent of DGKk dysregulation in PWS remains uncertain due to the limitations of current detection methods. This study will use advanced mass spectrometry techniques to obtain absolute and highly sensitive quantification of DGKk in cells and tissue extracts from various models of PWS. We will measure DGKk protein levels in several brain regions of interest in PWS mouse models, in particular the SNORD116-KO model, and investigate DGKk alterations in a neuronal model derived from PWS patient cells (iPSC). This research will determine the importance and significance of DGKk alterations in PWS and help demonstrate its contribution to pathology. These results could improve our understanding of the variability of PWS symptoms and open up new avenues for personalized treatment strategies.

Genetic variants of CTNNB1 cause CTNNB1 syndrome, an intellectual disability syndrome presenting with developmental delay, microcephaly, behavioral disturbances, visual defects and movement disorders. Fostered by the efforts of patient organizations, several attempts to develop disease-modifying treatments are ongoing. Therapeutic strategies include gene replacement therapy, RNA-based therapies or small molecules targeting Wnt/beta-catenin signaling pathway. As for all rare diseases, clinical trial readiness relies on several critical factors, including better knowledge of the disease’s natural history, coordinated care networks, establishment of important-to-address outcome for patients and caregivers, and above all the development and validation of reliable outcome measures able to detect minimal important differences in patients’ status. Given the broad range of symptoms, measuring CTNNB1 syndrome severity is particularly challenging. Most available clinical rating scales for motor disorders are tailored to the assessment of single disorders and do not accurately reflect the motor impairment in CTNNB1 syndrome. Functional classification systems are useful to score patients’ disability, but may not allow to detect small but significative improvements, and lack important information on more specific aspects. Additionally, administering different scales is redundant, time-consuming and difficult to perform due to limited patient collaboration. For these reasons, a disease-specific severity scale for CTNNB1 syndrome should be developed.
Through a rigorous and detailed protocol, we will provide to the research community a freely available and practical tool to assess the severity of most common and disabling symptoms of CTNNB1 syndrome (cognitive impairment, behavioral and motor disorders). CTNNB1-Clinical Rating Scale will represent a pivotal tool for monitoring disease severity and to test the efficacy of the novel, disease-modifying treatment in the pipeline.

Intellectual disability and autism are common disorders. To a large extend, these disorders have a genetic component. The common goal of the attendants of this conference are a) to identify the genetic causes of the disorder and b) to develop therapy for these disorders. As scientists, our work is significantly catalyzed by interactions with other scientists. This inspires us and prevents us in many occasions from reinventing the wheel. The Troina Meeting the Genetics of Neurodevelopmental Disorders is an annual event since 2005 and has attracted many, if not all of the most influential geneticists in the world over the years. Our unique format guarantees ample discussion and interactions between scientists at all levels of their career, from established and distinghuished professors to starting PhD student In the history of the meeting, this has for instance led to the identification of novel disorders, etc., etc. We ask for a smal donation to be able to continue our initiative.

Williams syndrome (WS) is a rare genetic disorder that affects brain development, leading to intellectual disability, high social tendencies, and difficulties in problem-solving, spatial awareness, and anxiety regulation. It is caused by the deletion of a group of genes on chromosome 7, including GTF2I, which plays a crucial role in brain function. Research suggests that this gene’s absence contributes to the cognitive and social challenges seen in WS.
Currently, treatments for WS focus on managing symptoms rather than addressing the underlying brain changes. Our research aims to explore a new approach—targeting brain myelination, a process essential for efficient communication between brain cells. Myelin is a protective layer that helps nerve signals travel quickly and accurately, allowing the brain to function smoothly. We recently discovered that individuals with WS and relevant mouse models have deficits in myelination, which could contribute to cognitive and behavioral symptoms.
To address this, we are testing 4-aminopyridine (4-AP), an FDA-approved drug known to enhance nerve signal transmission and myelination. In preliminary studies, we found that a single dose of 4-AP improved brain signal transmission and motor skills in a WS-related mouse model. This project will take the next critical step—testing whether chronic 4-AP treatment, started early in development, can improve cognition, social behavior, and anxiety in a WS mouse model that more closely resembles the human condition.
By targeting a fundamental brain function rather than just symptoms, this study may pave the way for a new treatment strategy for WS. If successful, our findings could also provide insights into other neurodevelopmental disorders that involve myelination deficits, such as autism and schizophrenia.

Angelman syndrome (AS) is a rare genetic disorder caused by the loss of a key protein called UBE3A, which is essential for normal brain function. While the gene for this protein is still present from the father, it remains switched off in brain cells due to a process called genomic imprinting. As a result, individuals with AS experience significant developmental challenges, including severe movement difficulties, lack of speech, intellectual disability, and sleep problems.
One of the most common and troubling symptoms of AS is epilepsy, affecting more than 80% of individuals. Seizures often start early in childhood and can be difficult to control with standard treatments. Despite ongoing research, scientists still do not fully understand why the loss of UBE3A causes these neurological symptoms, and there is no cure yet.
Evidence suggests that AS also affects the body’s internal clock, known as the circadian rhythm, which controls sleep-wake cycles. People with AS often struggle with poor sleep, frequent nighttime awakenings, and abnormal melatonin levels. Additionally, epilepsy in AS suggests a problem with brain inhibition, meaning that neurons may be overly active and unable to properly regulate signals.
This research aims to uncover a possible common link between disrupted sleep patterns and excessive brain activity in AS. The hypothesis is that both issues arise from problems in regulating chloride levels inside neurons, which in turn are caused by defects in how proteins are processed and maintained in brain cells.
By identifying this shared underlying mechanism, the study could open new doors for treatments that target a root cause of multiple AS symptoms, rather than addressing each symptom separately.