Prader-Willi/Angelman (SNRPN) Region Probe

SNRPN/Imprinting Centre: Red Fluorophore
15q Subtelomere Specific Probe (clone 154P1): Green Fluorophore

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are caused by the paternal or maternal loss of genes in 15q11-13, respectively. Around 70% of patients exhibit a deletion of 3-4 Mb, whilst 2-4% of patients exhibit a smaller deletion of the Imprinting Centre (IC). Uniparental disomy accounts for the remaining patients with PWS, but only 80% of AS patients exhibit these defects. The remaining AS are believed to have mutations of one or more genes (UBE3A) in the critical region.

SNRPN is one of four imprinted loci mapping to the critical region. The imprinting centre is 100 Kb proximal to SNRPN. Parental deletions or mutations in the IC impair the imprinting process in 15q11-13 and thus cause the two distinct diseases. The probe mixture cannot detect small deletions of the Angelman region or uniparental disomy.

The Prader-Willi/Angelman Region probe contains the SNRPN gene and the imprinting centre. A 15q subtelomere probe is supplied and both probes are directly labelled, SNRPN with a red fluorophore (Texas Red spectrum) and 15qter with a green fluorophore (FITC spectrum).