Les frères Taquins : Cirque Roncalli, 1994

Olivier Taquins en automate et son partenaire

Exome Sequencing Is an Efficient Tool for Variant Late-Infantile Neuronal Ceroid Lipofuscinosis Molecular Diagnosis

<div><p>The neuronal ceroid-lipofuscinoses (NCL) is a group of neurodegenerative disorders characterized by epilepsy, visual failure, progressive mental and motor deterioration, myoclonus, dementia and reduced life expectancy. Classically, NCL-affected individuals have been classified into six categories, which have been mainly defined regarding the clinical onset of symptoms. However, some patients cannot be easily included in a specific group because of significant variation in the age of onset and disease progression. Molecular genetics has emerged in recent years as a useful tool for enhancing NCL subtype classification. Fourteen NCL genetic forms (CLN1 to CLN14) have been described to date. The variant late-infantile form of the disease has been linked to <i>CLN5</i>, <i>CLN6</i>, <i>CLN7</i> (<i>MFSD8</i>) and <i>CLN8</i> mutations. Despite advances in the diagnosis of neurodegenerative disorders mutations in these genes may cause similar phenotypes, which rends difficult accurate candidate gene selection for direct sequencing. Three siblings who were affected by variant late-infantile NCL are reported in the present study. We used whole-exome sequencing, direct sequencing and <i>in silico</i> approaches to identify the molecular basis of the disease. We identified the novel c.1219T>C (p.Trp407Arg) and c.1361T>C (p.Met454Thr) <i>MFSD8</i> pathogenic mutations. Our results highlighted next generation sequencing as a novel and powerful methodological approach for the rapid determination of the molecular diagnosis of NCL. They also provide information regarding the phenotypic and molecular spectrum of CLN7 disease.</p></div

A) Pedigree of the NCL family. Black symbols refer to affected individuals.

<p>Half-black symbols into third and fourth generation individuals symbols (III:6, III:7, IV:3) represents the <i>MFSD8</i> c.1219T>C and c.1361T>C mutations at heterozygous state. <b>B)</b> Brain magnetic resonance imaging (T2-FLAIR image, axial section) of patient (P3) showing mild cerebral atrophy.</p

Comparative sequence analysis of MFSD8 orthologues.

<p>Residues at position 407 (W) and 454 (M) are indicated in bold and highlighted with grey shading.</p

Chromatograms showing <i>MFSD8</i> c.1219T>C (A) and c.1361T>C (B) mutations.

<p>WT: wild type sequence. C1: control 1 (III:6). C2: control 2 (III:7). P2: patient 2 (IV:2). C3: control 3 (IV:3). P3: patient (IV:4). Asterisks show the accurate position of relevant mutations.</p

Novel genes and mutations in patients affected by recurrent pregnancy loss

<div><p>Recurrent pregnancy loss is a frequently occurring human infertility-related disease affecting ~1% of women. It has been estimated that the cause remains unexplained in >50% cases which strongly suggests that genetic factors may contribute towards the phenotype. Concerning its molecular aetiology numerous studies have had limited success in identifying the disease’s genetic causes. This might have been due to the fact that hundreds of genes are involved in each physiological step necessary for guaranteeing reproductive success in mammals. In such scenario, next generation sequencing provides a potentially interesting tool for research into recurrent pregnancy loss causative mutations.</p><p>The present study involved whole-exome sequencing and an innovative bioinformatics analysis, for the first time, in 49 unrelated women affected by recurrent pregnancy loss. We identified 27 coding variants (22 genes) potentially related to the phenotype (41% of patients). The affected genes, which were enriched by potentially deleterious sequence variants, belonged to distinct molecular cascades playing key roles in implantation/pregnancy biology.</p><p>Using a quantum chemical approach method we established that mutations in MMP-10 and FGA proteins led to substantial energetic modifications suggesting an impact on their functions and/or stability.</p><p>The next generation sequencing and bioinformatics approaches presented here represent an efficient way to find mutations, having potentially moderate/strong functional effects, associated with recurrent pregnancy loss aetiology. We consider that some of these variants (and genes) represent probable future biomarkers for recurrent pregnancy loss.</p></div

Number of transcripts modified in uterus of R3 IRCS compared to C57BL6/J.

<p>Number of transcripts modified in uterus of R3 IRCS compared to C57BL6/J.</p

Gene list in the minimal <i>Led2min</i> region.

<p>Gene list in the minimal <i>Led2min</i> region.</p

Embryonic resorption rate in function of the type of crossing realized with IRCS and B6 mice.

<p>The results of different crosses (♀IRCS × ♂B6, ♀B6 × ♂IRCS and ♀B6 × ♂B6) are presented as the average (±SEM) of the embryonic resorption rate for (n) gestations.</p

Sequence variants identified in RPL patients.

<p>Sequence variants identified in RPL patients.</p