title: Clinical features and molecular genetics of two Tunisian families with abetalipoproteinemia.
abstract: Abetalipoproteinemia (ABL) is a rare monogenic disease characterized by very low plasma levels of cholesterol and triglyceride and almost complete absence of apolipoprotein B (apoB)-containing lipoproteins. Typically, patients present with failure to thrive, acanthocytosis, pigmented retinopathy and neurological features. It has been shown that ABL results from mutations in the gene encoding the microsomal triglyceride transfer protein (MTTP). Sanger sequencing of MTTP was performed for two unrelated consanguineous Tunisian families with two affected individuals each, presenting a more severe ABL phenotype than previously reported in the literature. The patients were found to be homozygous for two novel mutations. In the first family, a nonsense mutation, c.2313T>A, leading to a truncated protein (p.Y771X) was identified. In the second family, a splice mutation, IVS 9+2T>G, was found. These mutations are believed to abolish the assembly and secretion of apoB-containing lipoproteins.
authors.affiliation: Department of Molecular Neurobiology and Neuropathology, National Institute of Neurology, La Rabta, Tunis, Tunisia; National Institute on Aging, Porter Neuroscience Research Center, National Institutes of Health, Building 35, Room 1A1010, Bethesda, MD 20892, USA. Electronic address: benhamadm@mail.nih.gov.
authors.forename: Monia Benhamed
authors.initials: MB
authors.lastname: Hammer
authors.affiliation: Department of Molecular Neurobiology and Neuropathology, National Institute of Neurology, La Rabta, Tunis, Tunisia.
authors.forename: Ghada
authors.initials: G
authors.lastname: El Euch-Fayache
authors.affiliation: Department of Molecular Neurobiology and Neuropathology, National Institute of Neurology, La Rabta, Tunis, Tunisia.
authors.forename: Houda
authors.initials: H
authors.lastname: Nehdi
authors.affiliation: Laboratory of Biochemistry, Rabta Hospital, Tunis, Tunisia.
authors.forename: Moncef
authors.initials: M
authors.lastname: Feki
authors.affiliation: Department of Molecular Neurobiology and Neuropathology, National Institute of Neurology, La Rabta, Tunis, Tunisia.
authors.forename: Wieme
authors.initials: W
authors.lastname: Maamouri-Hicheri
authors.affiliation: Department of Molecular Neurobiology and Neuropathology, National Institute of Neurology, La Rabta, Tunis, Tunisia.
authors.forename: Fayçal
authors.initials: F
authors.lastname: Hentati
authors.affiliation: Department of Molecular Neurobiology and Neuropathology, National Institute of Neurology, La Rabta, Tunis, Tunisia.
authors.forename: Rim
authors.initials: R
authors.lastname: Amouri
mesh_terms: D000012:Abetalipoproteinemia / Q000097:blood / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D000050:Acanthocytes / Q000473:pathology; D000293:Adolescent; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D018389:Codon, Nonsense; D005190:Family; D005260:Female; D005528:Foot / Q000473:pathology; D005530:Foot Deformities; D006801:Humans; D008297:Male; D009154:Mutation; D010375:Pedigree; D017422:Sequence Analysis, DNA; D014416:Tunisia; D055815:Young Adult
chemical_list: D002352:Carrier Proteins; D018389:Codon, Nonsense; C106092:microsomal triglyceride transfer protein
keywords: ABL; Ataxia; MTTP; Mutation; Tunisian