PLOD1 and Down syndrome: Taking advantage of a trisomic mouse model of Down Syndrome (DS; Ts65Dn mice) which displays subfertility and progressive cognitive impairments similar to that of DS patients, we have highlighted that these nonreproductive neurological symptoms closely paralleled a postpubertal loss of GnRH neurons and fibers in the hypothalamus as well as in extrahypothalamic regions, which is reflected by changes in the levels and pattern of release of LH in the blood.104