Surprising Benefit from GnRH Replacement in Down Syndrome

Trisomy 21, or Down syndrome (DS), produces progressive cognitive impairment and premature deposition of Alzheimer disease–like brain plaques and tangles at a young age. Investigators from Europe noted that gonadotropin-releasing hormone (GnRH)–producing neurons also diminish over time in people with DS and wondered if that might be responsible for cognitive loss.

Using a trisomy 21 mouse model that, like patients with DS, has subfertility, progressive cognitive decline, and decline in GnRH-producing neurons, the investigators found that the decline in GnRH neurons was linked to changes in the expression of several microRNAs (miRNAs) — including reductions in one miRNA known to enhance the maturation of GnRH neurons. Supplementing with this …