Genetics

Role of SNORD116/HBII-85 snoRNAs in Prader-Willi syndrome

Funding Year:

2011

Awarded To:

Giles Yeo, PhD

Amount:

$49,683

Institution:

University of Cambridge

R-loop formation and chromatin decondensation at the PWS critical locus

Prader-Willi syndrome (PWS) is a neurodevelopmental disorder with a known genetic etiology but a complex epigenetic basis. PWS is an imprinted disorder, meaning that genes expressed only on the paternal but not the maternal chromosome 15 are responsible. Furthermore, unlike genetic mutations that affect protein-coding genes, the smallest genetic deletions causing PWS only affect noncoding transcripts of RNA. At the heart of the minimally deleted region in PWS are two types of noncoding RNAs.

Funding Year:

2011

Awarded To:

Janine LaSalle, PhD

Amount:

$30,000

Institution:

University of California, Davis

Activation of the maternal allele

Prader-Willi syndrome (PWS) results from inactivation of a domain on the paternal chromosome 15 while the same domain on chromosome 15 that is of maternal origin is normally inactivated. This situation in Prader-Willi patients is therefore associated with complete silencing of a relatively large number of genes that are located in this domain. This silencing of the genes is therefore implicated in the various symptoms observed in Prader-Willi patients. It is presumed that the genes of the domain on the maternal chromosome 15 are intact and perfectly normal but unfortunately dormant.

Deletion vs. UPD: 70/30 or 50/50?

Most information about PWS starts out with a brief overview of the genetics of the condition. Deletion of chromosome 15 is listed as the most common cause of PWS, accounting for roughly 70% of cases.

Altering gene expression

Here's a very interesting summary of a research article just published in the journal Cell. The important point here (at least for the sake of this conversation) is not the prostate cancer link - but rather the identification of another protein that can change the methylation status of histones - thereby reactivating previously silent DNA.

A role for PWS-snoRNAs, finally!

There's a new paper out in a top journal, Science, on what is may be the first understanding of the underlying molecular basis of features of PWS - The snoRNA HBII-52 regulates alternative splicing of the serotonin receptor 2C -- I've put the link at the end of the message. Here's the lowdown:

Narrowing down the genetic region responsible for PWS

Below you'll find the abstract for a newly published paper trying to narrow down exactly which DNA sequences in the PW region of chromosome 15 are responsible for PWS.

Genetic characterization of PWS mouse - FPWR supported

Dr. Rob Nicholls has just published another study supported by FPWR. You may recall that his group developed a mouse model of PWS (and Angelmanâ€™s syndrome if inherited maternally) some years back. We are currently supporting his studies to better characterize that model.

Refining the genetic region critical for PWS

Below is a link to recently published paper from Dr. Francke's group at Stanford Univ. You might recall that Dr. Francke received an FPWR grant in the first funding cycle (2003), and the work in this publication was supported by those funds.

Genes in the BP1/BP2 interval on chromosome 15 identified

New research has identified genes affected in Prader-Willi patients by deletion. Deletions account for approximately 70% of PWS cases. There are two different sizes of deletion, with one type encompassing more genes than the other.