Down Syndrome Research and Practice 8(1)
Editorial from Down Syndrome Research and Practice, Volume 8, Issue 1.
Helen Fletcher, and Sue Buckley
Research in the area of phonological awareness has mainly focused on the nature of the relationship between reading ability and awareness of phonemes. However, a recent study of phonological awareness in children with Down syndrome questioned the existence of any necessary relationship (Cossu, Rossini & Marshall, 1993). This paper describes a study of phonological awareness in children with Down syndrome with varying levels of reading ability. The sample consisted of 10 male and 7 female children with Down syndrome (aged 9 years 2 months to 14 years 5 months). All children received a battery of tests which consisted of assessments of: 1) phonological awareness, 2) reading and spelling competence, 3) non-word reading and spelling ability, and 4) non-verbal measures. Children with Down syndrome demonstrated measurable levels of phonological awareness. Significant positive correlations were found between phonological awareness and: reading and spelling competence, ability to spell non-words and non-verbal measures.
Sebastiano Bianca, Marco Bianca, and Giuseppe Ettore
Infants with Down syndrome are known to have a high frequency of associated birth defects and some authors have suggested an association between Down syndrome and oesophageal atresia. We evaluated data from the Sicilian Registry of Congenital Malformations. Our finding of an incidence of 0.9% of oesophageal atresia in children with Down syndrome is more than 30 times higher than expected and more than reported in other studies where the association was present in 0.5% of cases. Our results confirm that the relationship between Down syndrome and oesophageal atresia is a non random association and the observation of this association in several populations with different genetic backgrounds allows us to conclude that a causal relationship may exist between Down syndrome and oesophageal atresia.
Jean Rondal, and Annick Comblain
Several cross-sectional studies and one longitudinal study were conducted on the language abilities of various cohorts of persons with Down syndrome aged between 14 and 50 years. No significant difference was observed on any of the receptive and productive morphosyntactic and lexical measures used, suggesting no marked change in the language of these persons from adolescence onto late adulthood. Repeated measures of cerebral metabolic rate (CMR) for fluorodeoxyglucose using a Positron Emission Tomography were made over a 4-year interval with 7 participants with Down syndrome aged between 37 and 49 years. A gradual decrease in global CMR for both cerebral hemispheres and for each participant was documented. It was particularly marked for 3 participants. However, no language deterioration could be associated with their marked lowering in CMR.
Corrado Romano, Rosa Pettinato, Letizia Ragusa, Concetta Barone, Antonino Alberti, and Pinella Failla
Zinc plays a central role in the immune system and has been found to be significantly reduced in people with Down syndrome. The effectiveness of zinc supplementation in people with Down syndrome has been reported with discordant results. A comparison was made between a range of clinical and biochemical variables and zinc levels in 120 individuals with Down syndrome. Two groups of participants, one with normal zinc levels and the second with low zinc levels, were compared on the following measures: growth hormone secretion, IgA and IgG antigliadin antibodies, presence of coeliac disease, T3, T4, fT3, fT4, TSH, hypothyroidism, hyperthyroidism, CD4/CD8 ratio, total immunoglobulins G and subclasses. No significant difference was found between the two groups, except for IgG4 which was, unexpectedly, significantly decreased in the group with normal zinc levels. In conclusion, an impairment of zinc blood level in individuals with Down syndrome does not necessarily impact on the organs and systems evaluated here.
Improving the classroom listening skills of children with Down syndrome by using sound-field amplification
Lee Bennetts, and Mark Flynn
Many children with Down syndrome have fluctuating conductive hearing losses further reducing their speech, language and academic development. It is within the school environment where access to auditory information is crucial that many children with Down syndrome are especially disadvantaged. Conductive hearing impairment which is often fluctuating and undetected reduces the child's ability to extract the important information from the auditory signal. Unfortunately, the design and acoustics of the classroom leads to problems in extracting the speech signal through reduced speech intensity due to the increased distance of the student from the teacher in addition to masking from excessive background noise. One potential solution is the use of sound-field amplification which provides a uniform amplification to the teacher's voice through the use of a microphone and loudspeakers. This investigation examined the efficacy of sound-field amplification for 4 children with Down syndrome. Measures of speech perception were taken with and without the sound-field system and found that the children perceived significantly more speech in all conditions where the sound-field system was used (p < .0001). Importantly, listening performance with the sound-field system was not affected by reducing the signal-to-noise ratio through increasing the level of background noise. In summary, sound-field amplification provides improved access to the speech signal for children with Down syndrome and as a consequence leads to improved classroom success.
Lital Boker, and Joav Merrick
The purpose of this study was to assess the incidence rates of leukaemia and other malignancies in persons with Down syndrome in Israel. The target population consisted of all persons with Down syndrome in the period of 1948-1995 and the study population was divided into two subgroups: (1) Persons born in Israel between 1979-95 (registry group) and (2) Persons currently or past-institutionalised, born before 1979 (institution group). The study population was linked to the Cancer Registry and cases that had been diagnosed through December 1995 were subsequently identified. The observed incidence rates were compared to expected rates in the general population. Standardised Incidence Ratios (SIR) and 95% confidence intervals were computed for each disease category. Analyses of results were performed separately for each subgroup of our study population. In the registry group seven cancer cases were observed as compared to 1.5 expected (SIR=4.67 95% CI 1.9-9.6), all of which were leukaemia cases. For the institution group a total of 17 cancer cases were observed compared to 12.8 expected. These included four cases of leukaemia (SIR=6.90 95% CI 1.9-17.7). An excess of gastric cancer in males, based on two cases (SIR=11.9 95% CI 1.3-42.9) was also observed. The significant excess of leukaemia in the Down syndrome population in Israel is in accordance with other international studies. The excess of gastric cancer in males with Down syndrome, which has not been reported before, should be further explored.