Increased prevalence of sex chromosome aneuploidies in specific language impairment and dyslexia

Aim: Sex chromosome aneuploidies increase the risk of spoken or written language disorders but individuals with specific language impairment (SLI) or dyslexia do not routinely undergo cytogenetic analysis. We assess the frequency of sex chromosome aneuploidies in individuals with language impairment or dyslexia. Method: Genome-wide single nucleotide polymorphism genotyping was performed in three sample sets: a clinical cohort of individuals with speech and language deficits (87 probands: 61 males, 26 females; age range 4 to 23 years), a replication cohort of individuals with SLI, from both clinical and epidemiological samples (209 probands: 139 males, 70 females; age range 4 to 17 years), and a set of individuals with dyslexia (314 probands: 224 males, 90 females; age range 7 to 18 years). Results: In the clinical language-impaired cohort, three abnormal karyotypic results were identified in probands (proband yield 3.4%). In the SLI replication cohort, six abnormalities were identified providing a consistent proband yield (2.9%). In the sample of individuals with dyslexia, two sex chromosome aneuploidies were found giving a lower proband yield of 0.6%. In total, two XYY, four XXY (Klinefelter syndrome), three XXX, one XO (Turner syndrome), and one unresolved karyotype were identified. Interpretation: The frequency of sex chromosome aneuploidies within each of the three cohorts was increased over the expected population frequency (approximately 0.25%) suggesting that genetic testing may prove worthwhile for individuals with language and literacy problems and normal non-verbal IQ. Early detection of these aneuploidies can provide information and direct the appropriate management for individuals. © 2013 The Authors. Developmental Medicine & Child Neurology published by John Wiley & Sons Ltd on behalf of Mac Keith Press.

Validação de espécies de Centropomus (Centropomidae, Perciformes) do litoral do Rio Grande do Norte através de caracterização citogenética e molecular

The Centropomidae family consists of three genera, Centropomus, Lates and Psammoperca. Centropomus is the most diverse group, with six Centropomus species occur in the Western Atlantic Ocean C. poeyi Chávez, 1961, C. parallelus Poey, 1860, C. mexicanus Bocourt, 1868, C. pectinatus Poey, 1860 and C. ensiferus Poey, 1860. Some of these species are considered cryptic, because of its morphological traits showed low resolution for identification purposes. Despite showing great interest as a natural resource and fish culture, aspects of their diversity and karyotypic patterns are poorly understood. In this work morphological identification and comparison of mitochondrial 16S gene sequence were used to identify the species of the genus Centropomus occurring in Rio Grande do Norte, northeastern Brazil. Two sepecies were identified, C. undecimalis and C. mexicanus, which had the chromosomal aspects analyzed, through Classical cytogenetic method analyzes (conventional staining, C-banding, Ag-NORs), fluorochrome staining AT- and GC-specific, replication bands by incorporating of the base analog 5-Bromo-2’-deoxyuridine (5-BrdU), in situ chromosomal mapping of (TTAGGG)n sequences and in situ chromosome mapping 18S and 5S rRNA genes. Both species show 2n=48 acrocentric chromosomes, with ribosomal sites (Ag-NOR/18S rDNA/ Mitramycin+) in second chromosomal pair, in telomeric position on the long arm in C. mexicanus and interstitial in C. undecimalis. The nuclear organization pair (pair 2) shown a resolutive cytotaxonomic marker for these two species. The generated data reveal a lower species diversity than previously believed, suggesting that greater attention should be paid in taxonomic identification of the species, in view of optimize commercial actions exploitation, biological conservation and cultivation.

Spatial organisation and behaviour of the parental chromosome sets in the nuclei of Saccharomyces cerevisiae × S. paradoxus hybrids

Peer reviewed

Spatial organisation and behaviour of the parental chromosome sets in the nuclei of Saccharomyces cerevisiae × S. paradoxus hybrids

Peer reviewed

Structure génétique des populations : modèle amérindien et les haplotypes du chromosome X

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Analyse d'un locus pour trait quantitatif pour l'hypertension sur le chromosome 10 du rat Dahl

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Interactions gène-environnement dans l'obésité associée à l'hypertension chez le rat : rôle du locus génique du TNF-[alpha] trouvé sur le chromosome-20

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Étude d'un locus pour trait quantitatif de l'hypertension sur le chromosome 3 du rat Dahl Salt-Sensitive

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Mise au point d'une nouvelle approche permettant la génération de délétions chevauchantes sur le chromosome X des cellules ES

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Localisation d'un locus pour trait quantitatif pour l'hypertension sur le chromosome 18 du rat Dahl

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Caractérisation de l'inactivation du chromosome X chez l'humain à la naissance : distribution et transmission des ratios d'inactivation

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Localisation d'un locus pour trait quantitif pour l'hypertension sur le chromosome 2 du rat Dahl

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Structure génétique des populations : modèle amérindien et les haplotypes du chromosome X

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Analyse d'un locus pour trait quantitatif pour l'hypertension sur le chromosome 10 du rat Dahl

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Interactions gène-environnement dans l'obésité associée à l'hypertension chez le rat : rôle du locus génique du TNF-[alpha] trouvé sur le chromosome-20

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.