Discovered a cause of intellectual disability and autism

The term intellectual disability includes a great number of disorders; we know the origin of some of them, but in other cases causes remain unknown. For example, Down syndrome occurs when there is an extra copy of chromosome 21 and the Rett syndrome is caused by mutations in the genes MECP2.

However, in other cases, the mechanisms that produce them have not been clearly identified; this happens in most autism spectrum disorders. A study led by Manel Esteller, professor of Genetics at the University of Barcelona (UB) and ICREA research professor in the Bellvitge Biomedical Research Institute (IDIBELL), shows a mechanism that identifies the cause of intellectual disability in these cases. The study has been published in the prestigious journal Genetics in Medicine.

The study has analysed 215 cases of patients with intellectual disability, autism or Rett Syndrome without a known genetic defect. “The aim was to determine if we were able to find a molecular cause. The process has allow detecting a new mutated gene that may cause these disorders”, explains Esteller.

“The gene is JMJD1C (jumonji domain containing 1C) and it is an epigenetic gene; in other words, its function is to control the activity of other genes”, adds Esteller. Only a small percentage of non-inherited intellectual disability is due to the mutation of this gene. However, the finding suggests that many genes with low alteration frequency are responsible for the cases with unknown origin. According to Esteller, “it has been proved that the characterised gene binds MECP2, so it may be also involved in rare Rett syndrome cases”.

The study has been developed thanks to the funds provided by the European Union, the Catalan and Spanish associations for Rett syndrome, a crowdfunding campaign on Verkami and the foundations Daniel Bravo and Finestrelles. Esteller emphasizes that this proves “society’s commitment to research activity”.

Article reference

Sáez, M. A.; Fernández Rodríguez, J.; Moutinho, C.; Sánchez Mut, J. V.; Gómez, A.; Vidal, I.; Petazzi, P.; Szczesna, K.; López Serra, P.; Lucariello, M.; Lorden, P.; Delgado Morales, R.; De la Caritat, O. J.; Huertas, D.; Gelpí, J. L.; Orozco, M.; López Doriga, A.; Milà, M.; Pérez Jurat, L. A,.; Pineda, M.; Armstrong, J.; Lázaro, C.; Esteller, M. “Mutations in JMJD1C are involved in Rett syndrome and intellectual disability”. Genetics in Medicine, July 2015. Doi: 10.1038 / gim.2015.100