( the mice had only one mutant copy of th...)How genetic malfunction causes a form of retardation

“Little is known about how genetic perturbations lead to mental retardation,?wrote Miller and colleagues. “Here, we have identified a signaling protein, SHP-2, that plays a key role in allowing environmental cues such as growth factors to instruct multipotent precursor cells to generate one cell type versus another. Moreover, we have shown that the same constitutively activated SHP-2 that occurs in a subpopulation of NS patients causes aberrant neural development in mice, providing a potential explanation for the cognitive dysfunction and neuroanatomical perturbations observed in this disorder. Such a mechanism may well generalize to other syndromes where signaling pathways that are important for neural cell genesis are genetically perturbed.?

The researchers speculated that “genetic perturbations such as those seen in NS, or perhaps even in more commonly studied disorders such as Rett Syndrome, might first perturb cell genesis, and then this might in turn alter many later aspects of neural development, ultimately resulting in impaired circuitry and cognitive dysfunction.?