1/1086. Orthodontic considerations in individuals with down syndrome: a case report. The skeletal and soft tissue features, aberrations in dental development, and periodontal and caries characteristics of down syndrome related to orthodontic treatment are discussed. A case report describing the successful orthodontic treatment of a 13-year-old boy with down syndrome and a severe malocclusion is presented. ( info) |
2/1086. A trisomic germ cell line and precocious chromatid segregation leads to recurrent trisomy 21 conception. A chromosomally normal 37-year-old woman was referred for preimplantation genetic diagnosis after having several conceptuses with trisomy 21. Segregation of chromosome 21 was assessed in unfertilised meiosis II oocytes and preimplantation embryos from PGD cycles using fluorescent in situ hybridisation (FISH). Of 7 preimplantation embryos, 5 were chromosomally abnormal with 4 having trisomy 21 and one being tetraploid. Of 4 oocytes, 3 had an abnormal chromosomal constitution with either an extra chromosome 21 or an extra chromatid 21. In one oocyte an extra chromatid 21 was detected in both the metaphase II complement and the first polar body providing the first direct evidence of a maternal trisomic germ cell line. Moreover, this result shows that the extra chromosome 21 can precociously divide into its two chromatids at the first meiotic division. ( info) |
3/1086. 'Identical' twins with discordant karyotypes. A chromosomal abnormality in one of the fetuses of a monozygotic twin pregnancy is a rare phenomenon. In the prenatal unit of our cytogenetics laboratory we have recently come across two such heterokaryotypic twin pregnancies. In both cases ultrasound abnormalities were detected in one fetus of each twin pair. Chromosomal analysis showed that one twin pregnancy was discordant for trisomy 21 and the other for 45,X. Ultrasonographic examination suggested a monochorionic twin pregnancy in each case and dna studies confirmed that both sets of twins were monozygotic. Both pregnancies were terminated. Biopsies taken from different sites of the placentas showed chromosomal mosaicism in both cases. There was no clear correlation between the karyotype found close to the site of the umbilical cord insertion in the placenta and the karyotype of the fetus. Sampling of amniotic fluid from both sacs is recommended in diamniotic twin pregnancies if one (or both) of the fetuses has ultrasound abnormalities, even if the twins are apparently monochorionic. ( info) |
4/1086. Epileptic falling spells after epidural haematoma in adult Down's syndrome. A 35-year-old man with Down's syndrome showed epileptic falling spells. He had suffered from a traumatic right-sided epidural haematoma 3 years before. It had been neurosurgically treated, but MRI taken 5 days later had revealed a small contracoup contusion at the left temporal lobe. His falling spell was a brief tonic seizure without disturbance of consciousness. Background activities of EEG consisted of slow alpha waves interspersed with sporadic theta waves and the amplitude at the left temporal area was lower than the opposite one. Interictal EEG showed sharp waves or sharp and slow wave complexes predominantly at the right temporo-centro-parietal area as well as diffuse, though predominantly at frontal areas, bursts of slow waves with high amplitude. The EEG suggested focal epileptic activities evolving into secondary generalization. SPECT of the brain showed the hypoperfusion at the left temporal area and at the right posterotemporo-parietal area, where the hypoperfusion was somewhat reduced after the improvement of seizures. seizures were well controlled with phenytoin combined with phenobarbital. The incidence of epilepsy in the Down's syndrome has been reported to increase after the middle age in association with the development of Alzheimer's neuropathology. When those people would sustain head injuries, it was necessary to follow carefully using SPECT and EEG. ( info) |
5/1086. Syntax PAL: a system to improve the written syntax of language-impaired users. In our work with children who have difficulty with spelling or with the physical action of writing, we have found a number of children who also have difficulty with written grammar. As an extension of PAL, an existing predictive spelling and typing aid, we have developed a writing aid to help these children with sentence construction. The enhanced system uses the syntax of the initial part of a sentence to enhance the position in the prediction list of syntactically correct words. It was postulated that this would discourage the use of incorrect syntax and encourage the use of correct syntax. In two case studies, the use of Syntax PAL significantly improved the quality and quantity of one child's written output, but had little effect on the other child's work. ( info) |
6/1086. trisomy 21 associated transient neonatal myeloproliferation in the absence of Down's syndrome. Although usually associated with Down's syndrome, transient neonatal myeloproliferation (TMD) can occur in the absence of a constitutional trisomy 21. This report describes two such cases, both of whom had a trisomy 21 restricted to clonal cells. Unlike in previous such reported cases, spontaneous morphological, cytogenetic, and molecular remission in both cases was followed by re-emergence, in one case, of an evolved clone with a more malignant phenotype which required pharmacological intervention. awareness that trisomy 21 bearing leukaemia in the neonatal period can be transient even in the absence of Down's syndrome is important to prevent unnecessary treatment. Equally, such cases require indefinite follow up as a proportion may have a recurrence which may require treatment. ( info) |
7/1086. Altered clearance of theophylline in children with down syndrome: a case series. down syndrome (DS) is a common cause of mental retardation resulting from trisomy 21. Previous reports have described altered pharmacokinetics and pharmacodynamics in patients with DS. The authors report six cases of infants (2-19 months) with DS who demonstrated altered theophylline pharmacokinetics. Clearance was prolonged in most of these patients. No overt toxicity to theophylline was noted in any of the cases. The authors propose that patients with DS are at increased risk for altered theophylline pharmacokinetics. The etiology for altered pharmacokinetics of theophylline may be due to the interface between normal developmental changes and pharmacogenetic differences associated with DS and/or the secondary disease states and concomitant drug therapy. ( info) |
8/1086. Intracranial germ cell tumors in children with and without down syndrome. PURPOSE: Two Chinese children with down syndrome affected by intracranial germ cell tumors are described. Because they represent two of eight affected patients in the current series from 1990 to 1996, it is postulated that such occurrence may be more than a coincidental event. patients AND methods: Two children with down syndrome developed germ cell tumors in atypical intracranial sites that affected basal ganglion and cerebellum. The pathology showed germinoma and yolk sac tumor, respectively. These were treated by radical surgical resection and chemotherapy with cisplatin, etoposide, and bleomycin, but without radiotherapy. RESULTS: One patient survived 3 years without radiologic evidence of tumor. The other died from infective complications caused by severe myelosuppression after chemotherapy. CONCLUSIONS: Subtle neurologic manifestations in developmentally handicapped patients with intracranial space-occupying lesions could result in delayed diagnosis. Children with down syndrome suffering from brain tumors may have a higher chance for germ cell tumors. Assay for alpha-fetoprotein and beta-human chorionic gonadotrophin could hasten diagnosis in some cases. This observation and review of literature suggest an increased risk of developing intracranial germ cell tumors in subjects with down syndrome. ( info) |
9/1086. Immunohistochemical study on transforming growth factor-beta1 expression in liver fibrosis of Down's syndrome with transient abnormal myelopoiesis. A case of Down's syndrome associated with liver fibrosis is reported. The fibrosis was diffusely distributed along sinusoids, and an excess of megakaryocytes was also found in the liver. To determine the mechanism of liver fibrosis in Down's syndrome, we immunohistochemically stained the liver with markers of myofibroblast-like cells, antialpha smooth muscle actin antibodies and antidesmin antibodies. The myofibroblast-like cells were found along sinusoids, suggesting that liver fibrosis in Down's syndrome is caused by the myofibroblast-like cells derived from Ito cells/lipocytes. The expression of transforming growth factor (TGF)-betal, which is an important mediator of the activation of lipocytes, was immunohistochemically examined. The accumulation of TGF-betal was observed in cells in the sinusoidal spaces, which involve the intracellular expression of megakaryocytes. Together, these findings suggest that megakaryocyte-derived TGF-betal is one of the likely candidates in the lipocyte activation of liver fibrogenesis in Down's syndrome. ( info) |
10/1086. comorbidity of autistic spectrum disorders in children with down syndrome. The aim of the study was to identify the comorbidity of autistic spectrum disorders in a population of children with down syndrome (DS). All children with DS within a defined population of South Birmingham were identified. The Asperger Syndrome Screening Questionnaire and the child Autism Rating Scale were completed and diagnosis made according to ICD-10 criteria following interview and observation. Thirty-three of 58 identified children completed the measures, four of whom received a diagnosis of an autistic spectrum disorder. This is equivalent to a minimum comorbid rate of 7%. The questionnaire items concerning social withdrawal, restricted or repetitive interests, clumsiness, and unusual eye contact were associated with an autistic disorder. Of the remaining 29 participating children, 11 also displayed marked obsessional and ritualistic behaviours. The comorbid occurrence of autism and DS is at least 7%. It is important that these children are identified and receive appropriate education and support. A full assessment of social, language, and communication skills and behaviour is crucial, particularly in children with DS who appear different from other children with DS. Potential mechanisms accounting for this comorbidity are discussed. ( info) |