Deletions of a differentially methylated CpG island at the SNRPN gene define a putative imprinting control region.
To determine the molecular basis of Prader-Willi syndrome (PWS) and Angelman syndrome (AS), we have isolated new transcripts from chromosome 15q11-q13. Two novel transcripts located within 300 kilobases telomeric to the small nuclear ribonucleoprotein-associated polypeptide N gene (SNRPN) were paternally expressed in cultured cells, along with SNRPN, defining a large imprinted transcriptional domain. In three PWS patients (two sibs), small deletions remove a differentially methylated CpG island containing a newly described 5' exon alpha of SNRPN, and cause loss of expression for the three imprinted transcripts and altered methylation over hundreds of kilobases. The smallest PWS deletion is familial and asymptomatic with maternal transmission. Our data imply the presence of a paternal imprinting control region near exon alpha.
Sutcliffe
J S
JS
Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030.
Nakao
M
M
Christian
S
S
Orstavik
K H
KH
Tommerup
N
N
Ledbetter
D H
DH
Beaudet
A L
AL
D017204:Angelman Syndrome / Q000235:genetics*; D001324:Autoantigens / Q000235:genetics*; D001483:Base Sequence; D002884:Chromosomes, Human, Pair 15; D015226:Dinucleoside Phosphates / Q000235:genetics*; D005220:Fathers; D018392:Genomic Imprinting; D006801:Humans; D008969:Molecular Sequence Data; D011218:Prader-Willi Syndrome / Q000235:genetics*; D017411:Ribonucleoproteins, Small Nuclear; D017384:Sequence Deletion; D055517:snRNP Core Proteins
D001324:Autoantigens; D015226:Dinucleoside Phosphates; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins; C526417:SNRPN protein, human; C015772:CpG dinucleotide