Skip to main content

Scientists discover unexpected link between genes

Scientists discover unexpected link between genes involved in human brain evolution and developmental disorders


The human brain stands out among mammals for its remarkably prolonged development. Synapses – critical connections between neurons of the cerebral cortex, the brain’s main hub for cognition – take years to mature in humans, compared to just months in species like macaques or mice. This extended development, also known as neoteny, is thought to be central to humans' advanced cognitive and learning abilities. On the other hand, it has been hypothesized that disruptions of brain neoteny could be linked to neurodevelopmental disorders such as intellectual disability and autism spectrum disorder.

The lab of Pierre Vanderhaeghen at the VIB-KU Leuven Center for Brain & Disease Research previously discovered that the prolonged development of the human cerebral cortex is mainly due to human-specific molecular mechanisms in neurons. Now, they are investigating these molecular timers in human neurons.

Unlocking the secrets to slow synapse development

In their latest study, the team tested the involvement of two genes, SRGAP2B and SRGAP2C, which are unique to humans. First identified by Cécile Charrier in the laboratory of Professor Franck Polleux (Columbia University, USA), these genes have been found to slow down synapse development when artificially introduced into mouse neurons of the cerebral cortex. The question if these genes function the same way in human neurons has remained unanswered.

To address this, Dr. Baptiste Libé-Philippot, a Postdoctoral Fellow in the Vanderhaeghen lab, switched off SRGA2B and SRGAP2C in human neurons, transplanted them into mouse brains, and carefully monitored synapse development over an 18-month period.

'We discovered that when you turn off these genes in human neurons, synaptic development speeds up at remarkable levels', says Dr. Libé-Philippot. 'By 18 months, the synapses are comparable to what we would expect to see in children between five and ten years old! This mirrors the accelerated synapse development observed in certain forms of autism spectrum disorder'.

Clues to human-specific brain disorder susceptibility

The team then investigated the underlying genetic mechanisms behind the pronounced effects of SRGAP2B and SRGAP2C on human neuron neoteny. They focused on the SYNGAP1 gene, an important disease gene known to be involved in intellectual disability and autism spectrum disorder.

Remarkably, they discovered that the SRGAP2 and SYNGAP1 genes act together to control the speed of human synapse development. Most strikingly, they found that SRGAP2B and SRGAP2C increase the levels of the SYNGAP1 gene and can even reverse some defects in neurons lacking SYNGAP1. This finding increases our understanding of how human-specific molecules influence neurodevelopmental disease pathways, shedding light on why such disorders are more prevalent in our species.

Professor Pierre Vanderhaeghen is looking forward to the future: 'This work gives us a clearer picture of the molecular mechanisms that shape the slow development of human synapses. It is amazing to find out that the same genes that are involved in the evolution of the human brain also have the potential to modify the expression of specific brain diseases. This could have important clinical relevance: more research is needed to understand how human-specific mechanisms of brain development affect learning and other behaviors and how their dysregulation can lead to brain disorders. It becomes conceivable that some human-specific gene products could become innovative drug targets'.

brain evolution, human evolution, developmental disorders, autism spectrum disorder, intellectual disability, epilepsy, genetic pathways, cognitive abilities, neurodevelopmental conditions, genetic research, evolutionary biology, human cognition, brain development, gene discovery, neurogenetics, brain complexity, risk factors, neurological disorders, mutation, gene expression,

#BrainEvolution, #HumanEvolution, #DevelopmentalDisorders, #Autism, #IntellectualDisability, #Epilepsy, #GeneticPathways, #CognitiveAbilities, #Neurodevelopment, #GeneticResearch, #EvolutionaryBiology, #HumanCognition, #BrainDevelopment, #GeneDiscovery, #Neurogenetics, #BrainComplexity, #RiskFactors, #NeurologicalDisorders, #GeneExpression, #BrainGenes

International Conference on Genetics and Genomics of Diseases 

Comments

Popular posts from this blog

Chromosomal Abnormalities

  Chromosomal Abnormalities Chromosome abnormalities refer to structural or numerical changes in chromosomes that can disrupt normal genetic function, leading to developmental disorders, congenital abnormalities, and various genetic diseases. These abnormalities may arise from errors in cell division, such as nondisjunction or chromosomal breakage, resulting in conditions like Down syndrome , Turner syndrome, Klinefelter syndrome , and various deletion or duplication syndromes. Understanding chromosome abnormalities is essential for genetic counseling, prenatal diagnosis, disease risk assessment, and research in cytogenetics and molecular genetics. Chromosome abnormalities, chromosomal disorders, chromosomal mutations, aneuploidy, structural chromosome abnormalities, nondisjunction, deletion syndrome, duplication syndrome , translocation, inversion, cytogenetics, karyotyping, prenatal diagnosis , genetic testing, genomic instability, Down syndrome, Turner syndrome, Klinefelter syn...

Multifactorial Genetic Conditions

Multifactorial Genetic Conditions Multifactorial genetic conditions are disorders caused by the combined effects of multiple genes and environmental factors , rather than a single gene mutation . These conditions do not follow classic Mendelian inheritance patterns and instead result from complex gene–environment interactions . Factors such as lifestyle, nutrition, infections, stress, and exposure to toxins can significantly influence disease onset and severity in genetically susceptible individuals. Common examples include diabetes, cardiovascular diseases , neural tube defects, asthma, and many neuropsychiatric disorders. Understanding multifactorial inheritance is essential for risk prediction, preventive medicine, and personalized healthcare strategies. Multifactorial inheritance, polygenic traits, gene–environment interaction, complex diseases, genetic susceptibility, environmental risk factors, non-Mendelian inheritance, disease predisposition, polygenic risk score, precision ...

Wolf-Hirschhorn Syndrome

 Wolf-Hirschhorn Syndrome Wolf–Hirschhorn Syndrome (WHS) is a rare genetic disorder caused by a partial deletion of the short arm of chromosome 4 (4p16.3). It is characterized by distinct craniofacial features often described as a “Greek warrior helmet” appearance, along with growth retardation, intellectual disability, seizures, and developmental delay. Affected individuals may also present with hypotonia , congenital heart defects, skeletal abnormalities, and delayed speech and motor skills. The severity of symptoms varies depending on the size of the chromosomal deletion . WHS typically occurs sporadically, though it can be inherited through chromosomal rearrangements. Early diagnosis through genetic testing and multidisciplinary medical care are essential for improving quality of life and managing associated complications. Wolf–Hirschhorn Syndrome, WHS, chromosome 4p deletion, 4p16.3 deletion, rare genetic disorder, developmental delay, intellectual disability, seizures, cran...