Luciana Silva

Relationship Between Polymorphisms in Genes Involved in Homocysteine Metabolism and Maternal Risk for Down Syndrome in Brazil

Associations between specific alleles of genes encoding enzymes in the methionine/homocysteine pathway and plasma homocysteine levels have been examined in different populations. In the present study, we determined polymorphisms of MTHFR A222V (677C > T), MTHFR E429A (1298A > C), MTRR I22M (66A > G), MTR D919G (2756A > G), and CBS 844ins68 and total plasma homocysteine levels (tHcy) among 154 mothers of children with Down syndrome (DS) and 158 control mothers from Brazil. Homocysteine levels were higher among DS mothers compared to control groups (10.437 vs. 8.600 respectively, P = 0.002). Only the 677T allele was associated with altered levels of tHcy in the case group (F(2,153) = 5.300; P = 0.006), primarily when homozygous. In the control group, the association of the TT genotype with higher levels of tHcy showed borderline significance (F(2,157) = 2.974; P = 0.054). All genotype distributions were similar in the two groups (P > 0.05), but the frequency of the 677T allele in the case group was significantly higher (χ2 = 3.862; DF = 1; P = 0.049; OR = 1.437 (1.001–2.062)). Although the 677T allele is associated with increased homocysteine levels, its presence has only a modest impact as an independent risk factor for DS. All the other polymorphisms did not show an association with risk for the syndrome, when evaluated separately (P > 0.05). However, when the presence of 677T, 1298C, 2756G, 66G, and 844ins68 alleles were evaluated together, the mothers of children with DS tend to have a higher number of uncommon alleles than the mothers with no previous affected child.

Cognitive dysfunction in children with sleep-disordered breathing

Two daily school periods are mandatory in Brazil owing to a shortage of academic facilities, which can decrease cognitive performance, especially in children with sleep-disordered breathing. This study aimed to verify the influence of starting time to school on cognition, comparing children with sleep disorders and normal children. Cognition was assessed in 79 children with sleep-disordered breathing, 468 children with nonrespiratory sleep disorders, and 633 normal control children. We analyzed total sleep time, starting time to school (morning or afternoon), and grades. First grade morning students with sleep-disordered breathing had 8.04 higher odds for cognitive dysfunction than normal children. For children with sleep-disordered breathing, second and third grade morning students had higher odds for cognitive dysfunction than those who studied in the afternoon (3.69 and 4.07). Fourth grade morning students had 8.27 higher odds for cognitive dysfunction than first grade children. In conclusion, sleep-disordered breathing, grades, and starting time to school interact to affect cognition in Brazilian children. (J Child Neurol 2005;20:400—404).

Sleep habits and starting time to school in Brazilian children

OBJECTIVE This study investigated the sleep habits in Brazilian children according to age, gender and starting time to school. METHOD We investigated 2,482 scholars aged 7 to 10 years. We compared sleep habits, gender, and starting time to school (morning and afternoon). RESULTS Sixty-one per cent of the children presented sleep rituals before sleep. Milk drinking before sleep was more frequent among seven years old children. We found a progressive reduction with age in keeping the lights on. Girls used to leave an object to bed more than boys did. Children that studied in the morning presented reduced total sleep time, sleep earlier, and nap more frequently than children that studied in the afternoon. CONCLUSION Starting time to school deeply influences sleep habits in Brazilian children from São Paulo City, in whom bed-time rituals are highly prevalent.

Cognitive dysfunction in children with sleep disorders

UNLABELLED Sleep is basic for physical and cognitive development and some studies have suggested that there may be an association between sleep disorders (SD) and cognitive dysfunction (CD) in children. Little is known, however, about SD and cognition in 7-10-year-old children, a fact that motivated the present study. METHOD We applied an SD questionnaire in 1180 children, 547 with SD and 633 without SD (CG), to assess cognition with a screening test (Bender Visual Motor Gestalt Test - BT). RESULTS We observed a similar frequency of CD in the children with SD (39%) and that ot the CG (40%). The 8-year-old children with SD presented a lower prevalence of CD than the CG (SD=6%, n=6; CG=13%, n=16; p=0.04). CONCLUSION The frequency of children with CD was equal in the study and control groups when considering the total sample (7- to 10-year-old children). In contrast to our expectations, the SD group of 8-year-old children presented a lower frequency of CD than the control group.

Marfan syndrome with a complex chromosomal rearrangement including deletion of the FBN1 gene

BackgroundThe majority of Marfan syndrome (MFS) cases is caused by mutations in the fibrillin-1 gene (FBN1), mapped to chromosome 15q21.1. Only few reports on deletions including the whole FBN1 gene, detected by molecular cytogenetic techniques, were found in literature.ResultsWe report here on a female patient with clinical symptoms of the MFS spectrum plus craniostenosis, hypothyroidism and intellectual deficiency who presents a 1.9 Mb deletion, including the FBN1 gene and a complex rearrangement with eight breakpoints involving chromosomes 6, 12 and 15.DiscussionThis is the first report of MFS with a complex chromosome rearrangement involving a deletion of FBN1 and contiguous genes. In addition to the typical clinical findings of the Marfan syndrome due to FBN1 gene haploinsufficiency, the patient presents features which may be due to the other gene deletions and possibly to the complex chromosome rearrangement.

PERSONALITY FEATURES IN A SAMPLE OF PSYCHOPHYSIOLOGICAL INSOMNIA PATIENTS

UNLABELLED The personality is the way people express themselves inside the environment they live. Sleep, quality or quantity, is a way of this physical and psychological expression of well being. Psychological factors, associated with psychophysiological insomnia (PPI) suggest an exaggerated perception of the difficulties to fall asleep. Worries, anxiety and the fear of not sleeping produce a bad sleep quality or sleep misperception. This study aims to identify personality features associated with PPI throughout Rorschach test (RT). METHOD We studied 32 patients with PPI (22 women), between 29 and 75 years old. We excluded patients with other sleeping or psychiatric disorders. We analysed the data from PPI patients submitted to the RT and we compared our results with the standard data. RESULTS We noticed a significant increase in global answers and a significant decrease in detailed answers; a trend of a low number of answers; great number of shape and animal answers, especially for women. CONCLUSION The features of the PPI patients personality were daily problems insecure and the incapability to avoid or remove them from their thought, making bedtime a time for worries to appear again and motivate insomnia.

Spinal muscular atrophy due to a “de novo” 1.3 Mb deletion: Implication for genetic counseling

We report a 3-year-old female with type I spinal muscular atrophy (SMA) born to a young and non-consanguineous couple. The child presented at two months of life with intense muscle weakness affecting predominantly proximal portions of the limbs, especially the legs, muscle hypotonia, fasciculation of the tongue, and severe respiratory muscle involvement. She remained in an intensive care unit with an assisted ventilation system from the fourth month of life. She died at 3 years of age from pulmonary infection. Molecular analysis confirmed the diagnosis of SMA but revealed that only the father was an asymptomatic carrier. Because SMN1 is mapped in a complex region containing repetitive elements due to an inverted duplication of approximately 500 kb, we carry out an SNP array and detected a 1.3 Mb deletion including the SMN1 and SMN2 genes that explain the disease.