Assessment of SNRPN expression as a molecular tool in the diagnosis of Prader-Willi syndrome.
BACKGROUND
Prader-Willi syndrome (PWS) is associated with lesions of the paternal chromosome 15q11- 13. Recently, loss of expression of a paternally expressed gene in this region, SNRPN, has been proposed as a molecular hallmark of PWS. The goal of this study was to determine the diagnostic accuracy of SNRPN expression in a well-characterized cohort of PWS patients.


METHODS
SNRPN expression was analyzed by reverse transcription coupled to polymerase chain reaction (RT-PCR). RNA was isolated from peripheral blood leukocytes and subjected to multiplex RT-PCR in which expression of SNRPN and a constituitively expressed internal control gene were analyzed. The amplified products were electrophoresed in agarose gels and visualized by ethidium bromide staining.


RESULTS
Multiplex RT-PCR was applied to RNAs isolated from 30 normal control subjects and 30 well- characterized PWS patients. All control patients expressed the SNRPN and internal control genes. In contrast, all 30 PWS patients demonstrated loss of SNRPN expression, with integrity of RNA being demonstrated by the presence of internal control gene expression.


CONCLUSIONS
Loss of SNRPN expression appears to be a consistent finding in PWS. Expression analysis of SNRPN offers a novel approach for the diagnostic evaluation of PWS that is robust and can be performed in a single day.
Carrel
A L
AL
Department of Pediatrics, University of Wisconsin Children's Hospital, Madison, Wisconsin 53792, USA.
Huber
S
S
Allen
D B
DB
Voelkerding
K V
KV
D000293:Adolescent; D001324:Autoantigens / Q000096:biosynthesis* / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics*; D015331:Cohort Studies; D005260:Female; D015870:Gene Expression; D018740:Genetic Heterogeneity; D018392:Genomic Imprinting; D006801:Humans; D008297:Male; D011218:Prader-Willi Syndrome / Q000175:diagnosis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins
D001324:Autoantigens; D017411:Ribonucleoproteins, Small Nuclear; C526417:SNRPN protein, human; D055517:snRNP Core Proteins