Neural Noise

EEG biomarker in Fragile X syndrome (translational)

2 min read

  • Mice modeling fragile X syndrome exhibit the same pattern of low-frequency brain wave differences as humans with the disorder.1
  • This low-frequency brain wave biomarker provides a translatable marker for treatment studies.1 1

Gardner updates

  • Elevated gamma spectral event peak power during auditory chirp is associated with neuropsychiatric features in Fragile X syndrome. 2

Weekly enrichment (2026-07-20)

  • The primary study (Kornfeld-Sylla, Bear and colleagues at MIT’s Picower Institute) is an open-access Nature Communications paper identifying a cross-species alpha-oscillation biomarker of fragile X syndrome shared between humans and Fmr1-/y mice.3
  • EEG was recorded over the occipital lobe in human boys and men (with or without FXS) and over the visual cortex (V1) surface in age-matched male mice (wild-type or Fmr1 knockout).3
  • The analysis subtracted the aperiodic background to isolate the periodic (“brain wave”) power spectrum, deliberately avoiding classic Greek-letter band matching, which was crucial because the shared phenotype fell in different bands across species (theta-like in mice vs alpha in humans).3
  • In adults of both species the low-frequency peak is shifted to a significantly slower center frequency in FXS; the murine correlate (periodic peak Pk1) sat at a median near 6.2 Hz in V1.3
  • In FXS boys and juvenile mice the frequency shift is milder but there is a juvenile-specific reduction in the power of that peak.3
  • The key peak is composed of two subpeaks, and the lower-frequency subpeak is the one that varies specifically with FXS; silencing somatostatin-expressing interneurons selectively affected this subpeak.3
  • Deletion of Fmr1 in cortical excitatory neurons and glia was sufficient to produce the alpha phenotype.3
  • A single dose of the GABAB-receptor agonist arbaclofen shifted the biomarker: wild-type mice responded at the lowest dose while Fmr1-/y mice needed a higher dose, demonstrating target engagement of the reduced GABA responsiveness underlying FXS.3
  • Data were pooled from collaborators at Boston Children’s Hospital, Cincinnati Children’s Hospital, the University of Oklahoma, and King’s College London.3
  • Context: arbaclofen (STX209) failed its primary social-behavior endpoints in phase 3 FXS trials despite promising phase 2 signals, which is exactly why objective EEG target-engagement markers matter; prior work showed single-dose racemic baclofen reduces aberrant high-frequency gamma power across both Fmr1 KO mice and humans with FXS.45

Footnotes

  1. https://news.mit.edu/2026/fragile-x-study-uncovers-brainwave-biomarker-bridging-humans-mice-0220 ↩ ↩2 ↩3

  2. https://www.sciencedirect.com/science/article/pii/S1388245726002129?dgcid=rss_sd_all ↩

  3. https://www.nature.com/articles/s41467-026-69243-0 ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9

  4. https://link.springer.com/article/10.1186/s11689-016-9181-6 ↩

  5. https://link.springer.com/article/10.1186/s11689-022-09455-9 ↩

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