Email updates

Keep up to date with the latest news and content from BMC Medical Genetics and BioMed Central.

Open Access Research article

Characterization of two common 5' polymorphisms in PEX1 and correlation to survival in PEX1 peroxisome biogenesis disorder patients

Sven Thoms*, Sabine Grønborg, Jana Rabenau, Andreas Ohlenbusch, Hendrik Rosewich and Jutta Gärtner

Author Affiliations

Department of Pediatrics and Pediatric Neurology, University Medical Center, University of Göttingen, Robert Koch Str. 40, 37099 Göttingen, Germany

For all author emails, please log on.

BMC Medical Genetics 2011, 12:109  doi:10.1186/1471-2350-12-109

Published: 16 August 2011

Abstract

Background

Mutations in PEX1 are the most common primary cause of Zellweger syndrome. In addition to exonic mutations, deletions and splice site mutations two 5' polymorphisms at c.-137 and c.-53 with a potential influence on PEX1 protein levels have been described in the 5' untranslated region (UTR) of the PEX1 gene.

Methods

We used RACE and in silico promoter prediction analysis to study the 5' UTR of PEX1. We determined the distribution of PEX1 5' polymorphisms in a cohort of 30 Zellweger syndrome patients by standard DNA sequencing. 5' polymorphisms were analysed in relation to the two most common mutations in PEX1 and were incorporated into a novel genotype-phenotype analysis by correlation of three classes of PEX1 mutations with patient survival.

Results

We provide evidence that the polymorphism 137 bp upstream of the ATG codon is not part of the UTR, rendering it a promoter polymorphism. We show that the first, but not the second most common PEX1 mutation arose independently of a specific upstream polymorphic constellation. By genotype-phenotype analysis we identified patients with identical exonic mutation and identical 5' polymorphisms, but strongly differing survival.

Conclusions

Our study suggests that two different types of PEX1 5' polymorphisms have to be distinguished: a 5' UTR polymorphism at position c.-53 and a promoter polymorphism 137 bp upstream of the PEX1 start codon. Our results indicate that the exonic PEX1 mutation correlates with patient survival, but the two 5' polymorphisms analysed in this study do not have to be considered for diagnostic and/or prognostic purposes.