Case report: Angelman syndrome in an individual with a small SMC(15) and paternal uniparental disomy: a case report with reference to the assessment of cognitive functioning and autistic symptomatology.

Doctors wrote up one teenage boy who had Angelman syndrome from paternal UPD. They gave IQ tests, language tests, and autism checklists to see how he was doing.

The goal was to compare his skills with the usual Angelman profile caused by big deletions.

The teen understood more words than he could say. He waved, smiled, and showed only mild autism traits.

This was milder than the classic picture seen in deletion cases.

Mertz et al. (2014) tracked 46 kids for 12 years and found the same trend: UPD groups keep better receptive language and fewer autistic signs than deletion groups.

Walz (2007) surveyed 248 parents and showed that while many Angelman kids flap or avoid eye contact, the pattern is not the same as idiopathic ASD; the UPD subgroup again looked milder.

An apparent contradiction pops up with Trillingsgaard et al. (2004): 13 of 16 Angelman kids met ADOS autism cut-offs. The difference is method: ADOS scores are lowered by low mental age, so kids can "screen positive" even when social interest is present. John et al. used clinical judgment, not just the cut-off, and saw fewer clear autism signs in UPD.

Together the papers say: expect better social interest and language understanding in UPD Angelman, but still run your autism screener and interpret it with care.

When you see an Angelman case, check the genetic report. If it says "paternal UPD," plan for stronger receptive skills and less severe social withdrawal. Push for AAC devices that match this comprehension level, and coach families that their child may connect more than they can speak. Use the ADOS or GARS, but explain to parents that a "positive" score may reflect delay, not true autism. This small shift in expectation can guide richer language goals and more social opportunities next session.