title: Identification of patients with abetalipoproteinemia and homozygous familial hypobetalipoproteinemia in Tunisia.
abstract: BACKGROUND
  Abetalipoproteinemia (ABL) and Homozygous Familial Hypobetalipoproteinemia (Ho-FHBL) are rare monogenic diseases characterised by very low plasma levels of cholesterol and triglyceride and the absence or a great reduction of apolipoprotein B (apoB)-containing lipoproteins. ABL results from mutations in the MTP gene; Ho-FHBL may be due to mutations in the APOB gene.
  
  
  METHODS
  We sequenced MTP and APOB genes in three Tunisian children, born from consanguineous marriage, with very low levels of plasma apoB-containing lipoproteins associated with severe intestinal fat malabsorption.
  
  
  RESULTS
  Two of them were found to be homozygous for two novel mutations in intron 5 (c.619-3T>G) and in exon 8 (c.923 G>A) of the MTP gene, respectively. The c.619-3T>G substitution caused the formation of an abnormal mRNA devoid of exon 6, predicted to encode a truncated MTP of 233 amino acids. The c.923 G>A is a nonsense mutation resulting in a truncated MTP protein (p.W308X). The third patient was homozygous for a novel nucleotide deletion (c.2172delT) in exon 15 of APOB gene resulting in the formation of a truncated apoB of 706 amino acids (apoB-15.56).
  
  
  CONCLUSIONS
  These mutations are expected to abolish the apoB lipidation and the assembly of apoB-containing lipoproteins in both liver and intestine.
authors.affiliation: Research Unit of Genetic and Biologic Factors of Atherosclerosis, Faculty of Medicine, Monastir, Tunisia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Najah
authors.forename: Enza
authors.initials: E
authors.lastname: Di Leo
authors.forename: Jelassi
authors.initials: J
authors.lastname: Awatef
authors.forename: Lucia
authors.initials: L
authors.lastname: Magnolo
authors.forename: Jgurim
authors.initials: J
authors.lastname: Imene
authors.forename: Elisa
authors.initials: E
authors.lastname: Pinotti
authors.forename: Mahjoub
authors.initials: M
authors.lastname: Bahri
authors.forename: Sihem
authors.initials: S
authors.lastname: Barsaoui
authors.forename: Ines
authors.initials: I
authors.lastname: Brini
authors.forename: Moncef
authors.initials: M
authors.lastname: Fekih
authors.forename: Mohamed Naceur
authors.initials: MN
authors.lastname: Slimane
authors.forename: Patrizia
authors.initials: P
authors.lastname: Tarugi
mesh_terms: D000012:Abetalipoproteinemia / Q000097:blood / Q000175:diagnosis / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001055:Apolipoproteins B / Q000097:blood / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005091:Exons / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D052476:Hypobetalipoproteinemia, Familial, Apolipoprotein B / Q000097:blood / Q000175:diagnosis / Q000235:genetics*; D007223:Infant; D007438:Introns / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D014416:Tunisia; D055815:Young Adult
chemical_list: D001055:Apolipoproteins B; D002352:Carrier Proteins; C106092:microsomal triglyceride transfer protein