Paternal UPD15: further genetic and clinical studies in four Angelman syndrome patients

Am J Med Genet. 2000 Jun 19;92(5):322-7. doi: 10.1002/1096-8628(20000619)92:5<322::aid-ajmg6>;2-y.


Among 25 patients diagnosed with Angelman syndrome, we detected 21 with deletion and 4 with paternal uniparental disomy (UPD), 2 isodisomies originating by postzygotic error, and 1 MII nondisjunction event. The diagnosis was obtained by molecular techniques, including methylation pattern analysis of exon 1 of SNRPN and microsatellite analysis of loci within and outside the 15q11-q13 region. Most manifestations present in deletion patients are those previously reported. Comparing the clinical data from our and published UPD patients with those with deletions we observed the following: the age of diagnosis is higher in UPD group (average 7 3/12 years), microcephaly is more frequent among deletion patients, UPD children start walking earlier (average age 2 9/12 years), whereas in deletion patients the average is 4 (1/2) years, epilepsy started later in UPD patients (average 5 10/12 years) than in deletion patients (average 1 11/12 years), weight above the 75th centile is reported mainly in UPD patients, complete absence of speech is more common in the deleted (88.9%) than in the UPD patients because half of the children are able to say few words. Thus, besides the abnormalities already described, the UPD patients have somewhat better verbal development, a weight above the 75th centile, and OFC in the upper normal range.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angelman Syndrome / genetics*
  • Child
  • Child, Preschool
  • Fathers*
  • Female
  • Genomic Imprinting*
  • Humans
  • Infant
  • Male
  • Microsatellite Repeats / genetics