A massive genomics study of people with intellectual disabilities performed in the Netherlands points to patient mutations in the TLK2 gene.
The placenta, a transient organ that links the developing embryo to its mother, is responsible for nutrient, waste and gas exchange between the foetus and the mother. Scientists at the Institute for Research in Biomedicine (IRB Barcelona) reveal that the TLK2 gene is vital for the development of the placenta and for embryo viability in mice. The results are published today in the journal Cell Death and Differentiation, a publication of the Nature group.
In spite of the difference between embryo development in mice and humans, this finding may be of biomedical relevance. Recent clinical data obtained from a massive genomic analysis of people with intellectual disabilities undertaken in the Netherlands detected mutations in 10 new genes, among them TLK2.
Travis H. Stracker, researcher at IRB Barcelona and head of the study, says, “We propose that mutations in the TLK2 gene in humans could result in impaired placental function during embryo development. Placental defects could result in insufficient oxygen during development and cause neurological disorders.”
Mice depleted of TLK2 produce a smaller embryo and placenta than normal mice; however, the researchers did not observe morphological defects. Defects in the placenta were found to cause embryo death at day 15 of a 20-day gestation period. The scientists detected a reduction in the expression of genes that are crucial for the differentiation of trophoblasts—a group of specialised cells that supply the embryo with…