RESUMO
Brain-derived neurotrophic factor (BDNF) plays an essential role in neuronal survival, especially in areas responsible for memory and learning. The BDNF Val66Met polymorphism has been described as a cognitive modifier in people with neuropsychiatric disorders. BDNF levels have been found to be low in children with learning disorder (LD). However, Val66Met polymorphism has not been studied before in such children. The aim was to investigate the presence of BDNF val66Met polymorphism in a group of children with specific LD and to verify its impact on their cognitive abilities. The participants in this cross-sectional study (N = 111) were divided into two groups: one for children with LD and the other for neurotypical (NT) ones. Children with LD (N = 72) were diagnosed according to the DSM-5 criteria. Their abilities were evaluated using Stanford-Binet Intelligence Scale, dyslexia assessment test, Illinois Test of Psycholinguistic Abilities, and phonological awareness test. Genotyping of BDNF Val66Met polymorphism was performed for all participants. The frequency of the Met allele was 26% among children with LD (6 children had homozygous, 26 had heterozygous genotype). The percentage of participants with deficits in reading, writing, and phonemic segmentation was higher in Met allele carriers when compared to non-Met allele carriers in LD group. The frequency of Met allele among NT children was 3.85% (0 homozygous, 3 children had heterozygous genotype) (p = 0.00001). The high frequency of Val66Met polymorphism among children with LD introduces the BDNF gene as a genetic modifier of learning performance in some children who manifest specific learning disorder (developmental dyslexia).
Assuntos
Fator Neurotrófico Derivado do Encéfalo , Deficiências da Aprendizagem , Humanos , Criança , Fator Neurotrófico Derivado do Encéfalo/genética , Polimorfismo de Nucleotídeo Único , Estudos Transversais , GenótipoRESUMO
BACKGROUND: Ubiquinone has antioxidant properties and has been linked to cognitive performance in some neuropsychiatric disorders. Its role in specific learning disorder manifestations has not been previously investigated. Therefore, the aim of this study was to measure the blood levels of ubiquinone in a group of children with specific learning disorder in comparison to typically developing children and to investigate the correlation between ubiquinone levels in children with specific learning disorder and some of their intellectual capabilities, reading, spelling and writing performance. METHODS: The study included 71 native Arabic speaking children: 31 in the specific learning disorder group and 40 in the typically developing (TD) group. The abilities of the children with specific learning disorder were evaluated by the Stanford-Binet Intelligence Scale-4th edition, the Dyslexia Assessment Test, and the Illinois Test of Psycholinguistic Abilities. The level of ubiquinone was measured in both groups by ELISA. Correlation between some aptitudes of children with specific learning disorder and the ubiquinone level was performed. RESULTS: The blood levels of ubiquinone in the children with specific learning disorder group were less than those in the TD group. Correlation analysis revealed a significant positive correlation between ubiquinone and the scores of backward digit span abilities. CONCLUSIONS: Ubiquinone has a role in the auditory working memory performance of children with specific learning disorder (with impairment in reading). The decreased levels of ubiquinone in this sample of children with specific learning disorder could have participated in the pathogenesis of this disorder.
RESUMO
Microtia is a congenital anomaly that is found with different prevalence among various populations. The exact etiology of ear anomalies is still unknown. We describe a new additional family with this rare disorder; Johnson-McMillin syndrome (JMS) where mother, son, and distant grandmother have multiple features of JMS in the form of microtia, facial asymmetry, ear malformation, hearing defect, and hypotrichosis. Variable presentations in this family could be referred to phenotype variation supporting an autosomal dominant pattern of inheritance. We observed that the mother was very sad and suffered from feelings of guilt. We found that she had isolated herself from family and community out of fear of being stigmatized and hurt. We concluded that the occurrence of microtia is of public health importance, adhering to traditional marriage customs in Egypt increases women's risk of giving birth to a disabled child, yet the mothers are blamed and shamed for their children's birth defects by their husbands, families, and communities, while the fathers are not stigmatized.