RESUMO
BACKGROUND: 45,X Turner syndrome (TS) female subjects have visuospatial skill and social cognition deficits that may arise from X-linked imprinting. The aim of the present study was to compare phenotypic characteristics and neurocognitive pattern of 12 monosomic TS girls, according to X-linked imprinting. METHODS: Microsatellite markers were used to determine the parental origin of the missing chromosome X. Wechsler Intelligence Scale for Children-Revised (WISC-R) was administered as measures of general intellectual functioning. The results were compared in TS patients with maternally derived X chromosome (Xm) and paternally derived X chromosome (Xp). RESULTS: Six out of 12 patients (50%) had Xm, and the other six (50%) had Xp chromosome. There was no difference in the total, verbal and performance IQ score between the TS subgroups with Xm and Xp. When the WISC-R subtest score patterns were compared, the mean arithmetic scores were significantly poorer in the Xm TS than in the Xp TS. CONCLUSION: In monosomic TS cases, paternal imprinting may predict arithmetic ability, on the other hand, reductionist consideration defined by genetic imprinting is not sufficient to confirm this. Further studies should be undertaken to clarify this situation.
Assuntos
Cromossomos Humanos X/genética , Genes Ligados ao Cromossomo X/fisiologia , Síndrome de Turner/genética , Síndrome de Turner/psicologia , Adolescente , Criança , Cognição/fisiologia , Feminino , Humanos , Fenótipo , Síndrome de Turner/patologiaRESUMO
Screening of 12 Turkish families with apparently autosomal recessive nonsyndromic sensorineural deafness without GJB2 and mtDNA m.1555A > G mutations for 11 previously mapped recessive deafness loci showed a family in which hearing loss cosegregated with the DFNB9 (OTOF) locus. Three affected children were later found to carry a novel homozygous c.3032T > C (p.Leu1011Pro) mutation in the OTOF gene. Both parents were heterozygous for the mutation. p.Leu1011Pro alters a conserved leucine residue in the C2D domain of otoferlin. Pure tone audiometry of the family showed severe to profound sensorineural hearing loss (with U-shape audiograms) in children, and normal hearing in the parents. Otoacoustic emissions and auditory brainstem response (ABR) suggested the presence of auditory neuropathy in affected individuals.
Assuntos
Genes Recessivos/genética , Perda Auditiva Neurossensorial/genética , Proteínas de Membrana/genética , Mutação de Sentido Incorreto , Sequência de Aminoácidos , Sequência de Bases , Sítios de Ligação/genética , Criança , Conexina 26 , Conexinas , Análise Mutacional de DNA/métodos , Saúde da Família , Feminino , Perda Auditiva Neurossensorial/patologia , Humanos , Masculino , Dados de Sequência Molecular , Linhagem , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Homologia de Sequência de Aminoácidos , TurquiaRESUMO
The 657del5 mutation of the NBS1 gene has been demonstrated in most patients with Nijmegen breakage syndrome (NBS). We identified four Turkish families in which probands were diagnosed as having NBS and found to be homozygous for the 657del5 mutation. The 657del5 allele in the four Turkish families had a single origin.