Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2011-6-28
pubmed:abstractText
Abetalipoproteinemia is a rare autosomal recessive disease characterized by low lipid levels and by the absence of apoB-containing lipoproteins. It is the consequence of microsomal triglyceride transfer protein (MTTP) deficiency. We report two patients with new MTTP mutations. We studied their functional consequences on the triglyceride transfer function using duodenal biopsies. We transfected MTTP mutants in HepG2 and HeLa cells to investigate their association with protein disulfide isomerase (PDI) and their localization at the endoplasmic reticulum. These children have a severe abetalipoproteinemia. Both of them had also a mild hypogammaglobulinemia. They are compound heterozygotes with c.619G>T and c.1237-28A>G mutations within the MTTP gene. mRNA analysis revealed abnormal splicing with deletion of exon 6 and 10, respectively. Deletion of exon 6 (?6-MTTP) introduced a frame shift in the reading frame and a premature stop codon at position 234. Despite the fact that ?6-MTTP and ?10-MTTP mutants were not capable of binding PDI, both MTTP mutant proteins normally localize at the endoplasmic reticulum. However, these two mutations induce a loss of MTTP triglyceride transfer activity. These two mutations lead to abnormal truncated MTTP proteins, incapable of binding PDI and responsible for the loss of function of MTTP, thereby explaining the severe abetalipoproteinemia phenotype of these children.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1098-1004
pubmed:author
pubmed:copyrightInfo
© 2011 Wiley-Liss, Inc.
pubmed:issnType
Electronic
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
751-9
pubmed:dateRevised
2011-10-27
pubmed:meshHeading
pubmed-meshheading:21394827-Abetalipoproteinemia, pubmed-meshheading:21394827-Agammaglobulinemia, pubmed-meshheading:21394827-Alternative Splicing, pubmed-meshheading:21394827-Amino Acid Sequence, pubmed-meshheading:21394827-Carrier Proteins, pubmed-meshheading:21394827-Child, pubmed-meshheading:21394827-Endoplasmic Reticulum, pubmed-meshheading:21394827-Exons, pubmed-meshheading:21394827-Female, pubmed-meshheading:21394827-HeLa Cells, pubmed-meshheading:21394827-Hep G2 Cells, pubmed-meshheading:21394827-Humans, pubmed-meshheading:21394827-Infant, pubmed-meshheading:21394827-Male, pubmed-meshheading:21394827-Microsomes, pubmed-meshheading:21394827-Molecular Sequence Data, pubmed-meshheading:21394827-Mutation, pubmed-meshheading:21394827-Protein Binding, pubmed-meshheading:21394827-Protein Disulfide-Isomerases, pubmed-meshheading:21394827-Triglycerides
pubmed:year
2011
pubmed:articleTitle
A severe form of abetalipoproteinemia caused by new splicing mutations of microsomal triglyceride transfer protein (MTTP).
pubmed:affiliation
INSERM/UMR 1048, Institut de Maladies Métaboliques et Cardiovasculaires, Université de Toulouse III, Toulouse, France.
pubmed:publicationType
Journal Article, Case Reports, Research Support, Non-U.S. Gov't