Molecular characterization of Tunisian families with abetalipoproteinemia and identification of a novel mutation in MTTP gene.

BACKGROUND: Abetalipoproteinemia (ABL; OMIM 200100) is a rare monogenic disorder of lipid metabolism characterized by reduced plasma levels of total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) and almost complete absence of apolipoprotein B (apoB). ABL results from genetic deficiency in microsomal triglyceride transfer protein (MTP; OMIM 157147). In the present study we investigated two unrelated Tunisian patients, born from consanguineous marriages, with severe deficiency of plasma low-density lipoprotein (LDL) and apo B. METHODS: Intestinal biopsies were performed and The MTTP gene was amplified by Polymerase chain reaction then directly sequenced in patients presenting chronic diarrhea and retarded growth. RESULTS: First proband was homozygous for a novel nucleotide deletion (c. 2611delC) involving the exon 18 of MTTP gene predicted to cause a non functional protein of 898 amino acids (p.H871I fsX29). Second proband was homozygous for a nonsense mutation in exon 8 (c.923 G > A) predicted to cause a truncated protein of 307 amino acids (p.W308X), previously reported in ABL patients. CONCLUSIONS: We discovered a novel mutation in MTTP gene and we confirmed the diagnosis of abetalipoproteinemia in new Tunisian families. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/8134027928652779.

[Butyrylcholinesterase activity in schizophrenic patients]. / Étude de l'activité butyrylcholinestérase chez des patients schizophrènes.

Butyrylcholinesterase (BChE) is an enzyme that has been investigated for its putative role in neurodegenerative and neuropsychiatric disorders. The aim of our work was to study BChE activity variations in schizophrenic patients and to investigate the involvement of this enzyme in schizophrenia and the importance of determining its activity in this disease. This cross-sectional study was carried out 131 (104 males and 27 females, mean age  = 38.0  ±â€Š 11.4 years) patients with chronic schizophrenia according DSM-IV criteria and 90 (64 males and 26 females, mean age  = 37.1  ±  15.9 years) healthy controls. Plasma BChE activity was determined by a kinetic method on Integra 400plus(TM) (Roche Diagnostics). Patients with schizophrenia had higher plasma BChE activity than controls (P < 0.0001). Female patients had higher BChE activity and smokers had lower BChE activity than non-smokers either in patients and controls. In patients with schizophrenia, BChE activity was not differed with age, alcohol status and clinical sub-types, and was not correlated to duration of illness. Concerning therapeutic features, BChE activity was higher in patients treated with antipsychotics monotherapy than those treated with an association of antipsychotic and anticholinergic drugs, without significant difference (P  = 0.196). Schizophrenic patients showed an increase BChE activity, which could be related to the pathophysiology of schizophrenia.