The invention concerns identification of human genes coding for a protein involved in synaptogenesis and whereof the mutation is associated in humans with the development of neurological diseases and/or predisposition to developing mental disorders or psychiatric diseases such as autism and asparagus syndrome. More particularly, the invention concerns a protein belonging to the family of human neuroligins (HNL's) and more particularly the HNL4X protein and its functional homologue HNL4Y encoded by a Y chromosome gene. The invention also concerns polynucleotides coding for the HNL4X and HNL4Y proteins mutated or not and mutated HNL3 proteins, the cellular expression vectors comprising the nucleic acid sequences expressing HNL3, HNL4X, HNL4Y mutated or not, and the polyclonal or monoclonal antibodies capable of being fixed on one of said peptides and/or polynucleotides mentioned above. The invention further concerns the use of polypeptides, polynucleotides, a vector, a host cell, and/or an antibody as defined above for preparing a composition for use in the treatment of a mental or neurological disease such as autism, asparagus syndrome, schizophrenia or the ADHD syndrome.
POLYNUCLEOTIDE AND PROTEIN INVOLVED IN SYNAPTOGENESIS, VARIANTS THEREOF, AND THEIR THERAPEUTIC AND DIAGNOSTIC USES