Genetic abnormalities in Prader-Willi syndrome and lessons from mouse models

Area of Science:

• Genetics
• Developmental Biology
• Neuroscience

Background:

• Prader-Willi syndrome (PWS) is a complex genetic disorder characterized by developmental and neurobehavioral issues.
• PWS arises from the loss of paternally expressed genes in the 15q11-q13 chromosomal region.
• This region contains multiple imprinted genes, with expression solely from the paternal allele.

Purpose of the Study:

• To investigate the role of imprinted genes in chromosome region 15q11-q13 in Prader-Willi syndrome.
• To identify candidate genes responsible for the failure-to-thrive phenotype observed in PWS neonates.
• To explore the evolutionary significance of imprinting in this critical genetic domain.

Main Methods:

• Analysis of imprinted genes in human chromosome 15q11-q13 and syntenic mouse chromosome 7C.
• Identification and characterization of the novel polycistronic SNURF-SNRPN gene.
• Examination of mutations and translocations associated with Prader-Willi syndrome.

Main Results:

• Multiple imprinted genes, including the novel SNURF-SNRPN gene, were identified in the PWS critical region.
• SNURF-SNRPN encodes two distinct proteins and is located within the imprinting control region.
• The SNURF-SNRPN locus is uniquely implicated in imprinting defects and translocations in PWS.

Conclusions:

• The SNURF-SNRPN gene is a strong candidate for mutations causing the neonatal failure-to-thrive phenotype in Prader-Willi syndrome.
• Evolutionary analysis suggests SNURF-SNRPN may function as a paternally expressed postnatal growth factor.
• Understanding SNURF-SNRPN's role is crucial for elucidating PWS pathogenesis and imprinting evolution.