Brief report: regression timing and associated features in MECP2 duplication syndrome.

Doctors looked at 17 boys who all have MECP2 duplication syndrome. They asked parents when each boy lost talking or other skills. They also checked who had seizures and who already had an autism label.

The team wanted to know if bigger DNA duplications cause worse regression. They wrote down every skill loss story in plain detail.

Eight boys lost words. Seven lost other skills like feeding or walking. The drops happened around the same time seizures started.

DNA size did not matter. A boy with a tiny duplication could lose more skills than a boy with a large one.

Mount et al. (2011) saw regression in about one of four kids with everyday autism. U et al. now show the same scary drop in a rare MECP2 group. The timing clue—seizures—matches the 2008 folate-deficiency cases in Paolo et al.

Pearson et al. (2018) warn that parent memories can paint a steeper drop than real life. U et al. used the same look-back method, so their numbers may feel larger than day-by-day tracking would show.

Thurm et al. (2018) call for biologic markers. U et al. answer with a practical one: watch for the first seizure; skills may slip soon after.

If you serve a boy with MECP2 duplication, mark the seizure-onset date in your calendar. Start extra language and daily-living probes that month. Early intense teaching right after seizures may keep skills from sliding. Share the seizure-skill link with families so they know what to watch and when to call you.