Selenium level correlates negatively with antibodies but positively with thyroid function in children with down syndrome: an Indonesian study.

Background: Children with Down syndrome (DS) are prone to developing autoimmune thyroid disease (AITD). Previous studies found lower selenium (Se) levels in children with AITD. Glutathione peroxidase-3 (GPx3) and selenoprotein-P (SePP) are widely used to measure Se levels. DS children tend to have lower Se levels, the main contributor to hypothyroidism in this population. This study aimed to analyze the Se's role in AITD in Indonesian children with DS. Methods: This cross-sectional study was conducted between February 2021-June 2022 at the Pediatric Outpatient Clinic of Dr Soetomo Hospital. DS children aged 1 month to 18 years were enrolled using consecutive sampling. Thyroid-stimulating hormone, free thyroxine, thyroid peroxidase (TPO-Ab) and thyroglobulin (Tg-Ab) autoantibody, GPx3, and SePP levels were measured in plasma samples using enzyme-linked immunosorbent assays. Statistical analyses used Chi-square, Mann-Whitney, and Spearman's rank correlation (r s). All results with p<0.05 were considered statistically significant. Results: Among 62 children with DS, SePP and GPx3 levels were significantly lower in those with AITD than those without AITD (p=0.013 and p=0.018, respectively). SePP and GPx3 levels correlated significantly with lower TPO-Ab (r s=-0.439 with p=1×10-5 and r s=-0.396 with p=0.001, respectively) and Tg-Ab (r s=-0.474 with p=1×10-5 and r s=-0.410 with p=0.001, respectively) levels. SePP levels correlated significantly with lower thyroid dysfunction incidence (r s=-0.252, p=0.048) in the AITD group. Conclusion: Selenium deficiency contributes to autoimmune process in the thyroid and to thyroid dysfunction in children with Down syndrome. Our findings recommend increasing Se levels through Se-containing foods to reduce the risks of AITD and thyroid dysfunction in DS children with AITD.

Comparison of dental caries experience and salivary parameters among children with Down syndrome and healthy controls in Chennai, Tamil Nadu.

Background: Although there have been numerous studies on dental caries in children with Down syndrome, the reports are conflicting. Studies on salivary chemical composition of children with Down syndrome are limited. Aim: The study aims to evaluate and compare the dental caries experience, salivary flow rate, pH, buffering capacity, and concentration of sodium, potassium, calcium, phosphorus, total proteins, and sialic acid in children with Down syndrome and healthy controls. Settings and Design: This was a cross-sectional study. Materials and Methods: Forty subjects with Down syndrome aged 5-18 years fulfilling the eligibility criteria from six special schools were selected by snowball sampling. Sixty healthy controls from six neighborhood schools fulfilling the eligibility criteria were selected by simple random sampling by matching the age, gender, and socioeconomic status. Sociodemographic data, oral hygiene practices, diet history and dental caries experience were recorded. About 6 mL of stimulated whole saliva was collected. Salivary flow rate, salivary pH, buffering capacity, and the concentration of sodium, potassium, calcium, phosphorus, total proteins, and sialic acid were determined. Results: There was no significant difference in the mean proportional caries rate between the study and control group (P = 0.90). Salivary pH (P = 0.00) and salivary sodium concentration (P = 0.02) were significantly low in the study group than the control group. Salivary buffering capacity was significantly higher in the study group than the control group (P = 0.001). Conclusions: Dental caries experience of children with Down syndrome was similar to the healthy controls. School health programs could be implemented in special schools to improve oral and general health of special children.

Risk of Severe Coronavirus Disease 2019 Disease in Individuals With Down Syndrome: A Matched Cohort Study From a Large, Integrated Health Care System.

BACKGROUND: Down syndrome (DS) is associated with an increased risk of infections attributed to immune defects. Whether individuals with DS are at an increased risk of severe coronavirus disease 2019 (COVID-19) remains unclear. METHODS: In a matched cohort study, we evaluated the risk of COVID-19 infection and severe COVID-19 disease in individuals with DS and their matched counterparts in a pre-COVID-19 vaccination period at Kaiser Permanente Southern California. Multivariable Cox proportion hazard regression was used to investigate associations between DS and risk of COVID-19 infection and severe COVID-19 disease. RESULTS: Our cohort included 2541 individuals with DS and 10 164 without DS matched on age, sex, and race/ethnicity (51.6% female, 53.3% Hispanic, median age 25 years [interquartile range, 14-38]). Although the rate of COVID-19 infection in individuals with DS was 32% lower than their matched counterparts (adjusted hazard ratio [aHR], 0.68; 95% confidence interval [CI], .56-.83), the rate of severe COVID-19 disease was 6-fold higher (aHR, 6.14; 95% CI, 1.87-20.16). CONCLUSIONS: Although the risk of COVID-19 infection is lower, the risk of severe disease is higher in individuals with DS compared with their matched counterparts. Better infection monitoring, early treatment, and promotion of vaccine for COVID-19 are warranted for DS populations.

The burden of chronic disease, multimorbidity, and polypharmacy in adults with Down syndrome.

Data on clinical characteristics of adults with Down syndrome (DS) are limited and the clinical phenotype of these persons is poorly described. This study aimed to describe the occurrence of chronic diseases and pattern of medication use in a population of adults with DS. Participants were 421 community dwelling adults with DS, aged 18 years or older. Individuals were assessed through a standardized clinical protocol. Multimorbidity was defined as the occurrence of two or more chronic conditions and polypharmacy as the concomitant use of five or more medications. The mean age of study participants was 38.3 ± 12.8 years and 214 (51%) were women. Three hundred and seventy-four participants (88.8%) presented with multimorbidity. The most prevalent condition was visual impairment (72.9%), followed by thyroid disease (50.1%) and hearing impairment (26.8%). Chronic diseases were more prevalent among participants aged >40 years. The mean number of medications used was 2.09 and polypharmacy was observed in 10.5% of the study sample. Psychotropic medications were used by a mean of 0.7 individuals of the total sample. The high prevalence of multimorbidity and the common use of multiple medications contributes to a high level of clinical complexity, which appears to be similar to the degree of complexity of the older non-trisomic population. A comprehensive and holistic approach, commonly adopted in geriatric medicine, may provide the most appropriate care to persons with DS as they grow into adulthood.

Multiorgan involvement and management in children with Down syndrome.

AIM: To review multiorgan involvement and management in children with Down syndrome (DS). METHODS: A literature review of articles from 1980 to 2019 using the MEDLINE interface of PubMed was performed using the following search terms- [Down syndrome] or [Trisomy 21] AND [Cardiology] or [Respiratory] or [neurodevelopment] or [epilepsy] or [musculoskeletal] or [immune system] or [haematological] or [endocrine] or [gastrointestinal] or [ophthalmological] or [Ear Nose Throat] or [dermatology] or [renal]. RESULTS: Congenital heart disease particularly septal defects occur in over 60% of infants with DS and 5%-34% of infants develop persistent pulmonary hypertension of the newborn irrespective of a diagnosis of congenital heart disease. Early recognition and management of aspiration, obstructive sleep apnoea and recurrent lower respiratory tract infections (LRTI) could reduce risk of developing pulmonary hypertension in later childhood. Children with DS have an increased risk of autistic spectrum disorder, attention deficit disorder and epilepsy particularly infantile spasms, which are associated with poor neurodevelopmental outcomes. Congenital anomalies of the gastrointestinal and renal system as well as autoimmune diseases, coeliac disease, arthropathy, thyroid dysfunction fold diabetes mellitus and dermatological conditions are more common. Hearing and visual anomalies are also well recognised association with DS (Table 1). CONCLUSION: Children with DS are at an increased risk of multiorgan comorbidities. Organ-specific health surveillance may provide holistic care for the children and families with DS throughout childhood.

Maternal risk factors for congenital heart defects in infants with Down syndrome from Western Mexico.

Atrioventricular septal defects (AVSDs) have been identified as intriguingly infrequent among Hispanics with Down syndrome (DS) born in the United States. The aim of this study was to evaluate the effect of possible maternal risk factors in the presence of congenital heart defects (CHDs) in Mexican infants with DS. A total of 231 live birth infants born with DS during 2009-2018 at the "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara (Guadalajara, Mexico) were ascertained in a case-control study. Patients with DS with any major CHD were included as cases and those without major CHD as controls. Potential risk factors were analyzed using logistic regression. Of eligible infants with DS, 100 (43.3%) had ≥1 major CHDs (cases) and were compared with a control group of 131 infants (56.7%) with DS without CHDs. Prevalent CHDs were ostium secundum atrial septal defects (ASDs) (46.9%), ventricular septal defects (27.3%), and AVSDs (14%). Lack of folic acid supplementation before pregnancy had a significant risk for CHDs in infants with DS (adjusted odds ratio [aORs] = 2.9 (95% confidence interval [95% CI]: 1.0-8.6) and in the analysis by subtype of CHDs, also, for the occurrence of ASDs (aOR = 11.5, 95% CI: 1.4-94.4). Almost half of the infants with DS in our sample had CHDs, being ASD the commonest subtype and AVSD the rarest. Our ethnic background alone or in concomitance with observed nutritional disadvantages seems to contribute differences in CHD subtype rates in our DS patients.

Prevalence of Mental Illness in Adolescents and Adults With Congenital Heart Disease from the Colorado Congenital Heart Defect Surveillance System.

The aim of this study was to estimate the prevalence of the full spectrum of mental illness in adolescents (aged 11 to 17) and adults (aged 18 to 64) with congenital heart defects (CHDs) in the population-level Colorado Congenital Heart Disease Surveillance System. Further we sought to investigate whether severity of the defect, frequency of recent cardiac procedures or underlying genetic disorders influence these estimates. The cohort included patients in clinical care for CHDs between January 1, 2011 and December 31, 2013, identified across multiple healthcare systems and insurance claims. Of 2,192 adolescents with CHDs, 20% were diagnosed with a mental illness with the most prevalent categories being developmental disorders (8%), anxiety disorders (6%), attention, conduct, behavior, impulse control disorders (6%), and mood disorders (5%). Of 6,924 adults with CHDs, 33% were diagnosed with a mental illness with the most prevalent categories being mood disorders (13%), anxiety disorders (13%), and substance-related disorders (6%). Greater lesion complexity was associated with a higher likelihood of anxiety and developmental disorders in both adolescents and adults. Adolescents and adults who had ≥2 cardiac procedures in the 3-year surveillance period had a 3- and 4.5-fold higher likelihood of a mental illness diagnosis, respectively, compared with those who had fewer than 2 cardiac procedures. Finally, patients with a genetic syndrome were more likely to have a mental illness diagnosis. In conclusion, mental illness is a prevalent co-morbidity in the adolescent and adult population with CHDs, thus comprehensive care should include mental health care.

Patterns of Dietary Supplement Use in Children with Down Syndrome.

OBJECTIVE: To determine the frequency of dietary supplement use for children with Down syndrome, and to obtain additional descriptive data regarding the age of initial treatment, cost, perceived benefits, and disclosure of use to the pediatrician. STUDY DESIGN: An anonymous questionnaire in English and Spanish was created for parents of children under age 18 years with Down syndrome. Surveys were completed in our clinic, or accessed on a number of Down syndrome-related websites. RESULTS: A total of 1167 responses were completed and analyzed. Forty nine percent of responders currently/previously gave their child supplement(s). The average child received 3 supplements (ranging from 1-18). Although Nutrivene, curcumin, and green tea extract were most common, over 150 different products were reported. Supplementation began most often in infancy, generally between age 4 and 6 months. Average cost was $90.53/month. Overall, 87% of users noted improvement, mainly in speech, immunity, and attention; 17% reported side-effects, predominantly gastrointestinal disturbance. Lack of improvement and cost were the main reasons for discontinuation. Most parents learned of supplements through a parent group or friend. In almost 20%, the pediatrician was unaware of the supplement use. CONCLUSIONS: Almost one-half of parents surveyed administer or have administered supplement(s) to their children with Down syndrome. Many of the supplements have concerning ingredient profiles and are given to children too young to articulate potential ill effects. Providers need to be aware of these products and question families about their use.

Risk factors for Down syndrome.

Down syndrome (DS) originates, in most of the cases (95 %), from a full trisomy of chromosome 21. The remaining cases are due to either mosaicism for chromosome 21 or the inheritance of a structural rearrangement leading to partial trisomy of the majority of its content. Full trisomy 21 and mosaicism are not inherited, but originate from errors in cell divisions during the development of the egg, sperm or embryo. In addition, full trisomy for chromosome 21 should be further divided into cases of maternal origin, the majority, and cases of paternal origin, less than 10 %. Among cases of maternal origin, a further stratification should be performed into errors that have occurred or originated during the first meiotic division in the maternal grandmother's body and errors that occurred later in life during the second maternal meiotic division. This complex scenario suggests that our understanding of the risk factors for trisomy 21 should take into account the above stratification as it reflects different individuals and generations in which the first error has occurred. Unfortunately, most of the available literature is focused on maternal risk factors, and the only certain risk factors for the birth of a child with DS are advanced maternal age at conception and recombination errors, even though the molecular mechanisms leading to chromosome 21 nondisjunction are still a matter of debate. This article critically reviews the hypotheses and the risk factors which have been suggested to contribute to the birth of a child with DS, including folate metabolism, dietary, lifestyle, environmental, occupational, genetic and epigenetic factors, with focus on maternal and paternal risk factors, and taking into account the possible contribution of the maternal grandmother and that of the developing trisomic embryo, in a complex scenario depicting the birth of a child with DS as the result of complex gene-environment interactions and selection processes involving different generations.

Integrated care for Down syndrome.

Down syndrome (DS), caused by an extra copy of chromosome 21 (trisomy 21), is the most intensively studied human aneuploidy condition. It is the leading cause of intellectual disability and birth defects. Although most prenatally diagnosed DS fetuses are aborted in Taiwan, there are still some infants with DS who are diagnosed after birth. In addition to intellectual disability, people with DS face systemic problems that include short stature, dysmorphism, congenital heart disease, congenital anomalies of gastrointestinal and genitourinary tracts, abnormal endocrine function, leukemia and leukemoid reactions. To provide better care for people with DS in Taiwan, we began the DS multi-disciplinary clinic that has opened once per month since November 2013. The multi-disciplinary clinic consists of several subspecialists who provide care for DS people. To date, approximately 200 patients have used the clinic. The average number of patients who use the clinic per month is 27±6 with a mean patient age of 16±12 years old (range 0.3-53 years). The average number of patients per specialist on each clinic day is 5.2±4.9 (range 0.5-20.9 patients). We focus on early detection and prevention of medical and developmental issues associated with DS. This coordinated approach allows DS patients and family to have more comprehensive care.

First trimester screening cut-offs for noninvasive prenatal testing as a contingent screen: Balancing detection and screen-positive rates for trisomy 21.

OBJECTIVE: To provide data on how screen-positive and detection rates of first trimester prenatal screening for fetal Down syndrome vary with changes in the risk cut-off and maternal age to inform contingency criteria for publicly funded noninvasive prenatal testing. MATERIALS AND METHODS: First trimester screening and diagnostic data were collected for all women attending for first trimester fetal aneuploidy screening in Western Australia between 2005 and 2009. Prenatal screening and diagnostic data were linked to pregnancy outcomes, including data from the Midwives' Notification System and the Western Australian Registry of Developmental Anomalies. The prevalence of Down syndrome and performance of screening by risk cut-off and/or for women >35 years were analysed. RESULTS: The current screening risk cut-off of 1:300 has screen-positive and detection rates of 3.5% and 82%. The screen-positive rate increases by 0.7-0.8% for each 100 point change in risk, up to 19.2% at 1:2500 (96% detection rate). Including all women >35 years as screen positive would increase the screen-positive rate and detection rates to 30.2% and 97.2%. CONCLUSION: Variation in screening risk cut-off and the use of maternal age to assess eligibility for noninvasive testing could significantly impact the demand for, and cost of, the test. A contingent first trimester screening approach for risk assessment is superior to the use of a combination of screening and maternal age alone. These data will inform decisions regarding the criteria used to determine eligibility for publicly funded noninvasive prenatal testing.

Risk factors for mortality in Down syndrome.

BACKGROUND: Down syndrome is a genetic condition that contributes to a significantly shorter life expectancy compared with the general population. We investigated the most common comorbidities in a population of acute hospital patients with Down syndrome and further explored what the most common risk factors for mortality are within this population. METHOD: From our database of one million patients admitted to National Health Service (NHS) Trusts in northern England, we identified 558 people who had Down syndrome. We compared this group with an age- and gender-matched control group of 5580 people. RESULTS: The most prevalent comorbid diseases within the Down's population were hypothyroidism (22.9%) and epilepsy (20.3%). However, the conditions that had the highest relative risks (RRs) in the Down's population were septal defects and dementia. Respiratory failure, dementia and pneumonia were the most significantly related comorbidities to mortality in the Down syndrome population. In the control population, respiratory failure, dementia and renal failure were the most significant disease contributors. When these contributors were analysed using multivariate analysis, heart failure, respiratory failure, pneumonia and epilepsy were the identified risk factors for in-hospital mortality in the Down syndrome population. Respiratory failure was the sole risk factor for mortality in the Down syndrome population [RR = 9.791 (1.6-59.9) P ≤ 0.05], when compared with the risk factors for mortality in the control population. CONCLUSIONS: There is significant medical morbidity in Down syndrome. This morbidity contributes to the lower life expectancy. Respiratory failure is a risk factor for mortality in Down syndrome. We need to thoroughly investigate people with Down syndrome to ensure any treatable illnesses are well managed.

Outcomes of children exposed in utero to chemotherapy for breast cancer.

INTRODUCTION: The incidence of breast cancer diagnosed during pregnancy is expected to increase as more women delay childbearing in the United States. Treatment of cancer in pregnant women requires prudent judgment to balance the benefit to the cancer patient and the risks to the fetus. Prospective data on the outcomes of children exposed to chemotherapy in utero are limited for the breast cancer population. METHODS: Between 1992 and 2010, 81 pregnant patients with breast cancer were treated in a single-arm, institutional review board-approved study with 5-fluorouracil, doxorubicin, and cyclophosphamide (FAC) in the adjuvant or neoadjuvant setting. Labor and delivery records were reviewed for each patient and neonate. In addition, the parents or guardians were surveyed regarding the health outcomes of the children exposed to chemotherapy in utero. RESULTS: In total, 78% of the women (or next of kin) answered a follow-up survey. At a median age of 7 years, most of the children exposed to chemotherapy in utero were growing normally without any significant exposure-related toxicity or health problems. Three children were born with congenital abnormalities: one each with Down syndrome, ureteral reflux or clubfoot. The rate of congenital abnormalities in the cohort was similar to the national average of 3%. CONCLUSIONS: During the second and third trimesters, pregnant women with breast cancer can be treated with FAC safely without concerns for serious complications or short-term health concerns for their offspring who are exposed to chemotherapy in utero. Continued long-term follow-up of the children in this cohort is required. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00510367. Other Study ID numbers: ID01-193, NCI-2012-01578. Registration date: 31 July 2007.

Integrated and first trimester prenatal screening in California: program implementation and patient choice for follow-up services.

OBJECTIVES: The California Prenatal Screening Program serves over 350,000 women annually. This study examines utilization rates for the various screening options and patient choices regarding follow-up services. METHODS: The study tracked patients with first trimester positive results for Down syndrome to examine patient decisions regarding follow-up services and/or additional screening and to identify determinants of patient decisions. For first trimester screen positive women who elected further screening, second trimester integrated screening results were analyzed. The Genetic Disease Screening Program Chromosome Registry was used to identify Down syndrome cases. RESULTS: Ethnicity, but not age, was a strong predictor of acceptance of prenatal diagnosis. Approximately 47% of first trimester screen positive women opted for further screening. Among these women, 46% percent received an integrated screen negative result. All but one confirmed Down syndrome case in this cohort were still screen positive. CONCLUSIONS: Data from the California Prenatal Screening Program indicate that all of the major screening modalities continue to be utilized. The wide range of choices made by women with screen positive results demonstrate the importance of including multiple options within the Program. Providing integrated screening to first trimester Down syndrome screen positive women reduced the number of unnecessary invasive procedures.

Oxidative stress and memory decline in adults with Down syndrome: longitudinal study.

By the age of 40, virtually all patients with Down syndrome (DS) have neuropathological changes characteristic of Alzheimer's disease (AD). The aim of our study was to investigate whether the levels of superoxide dismutase enzymes (SOD), glutathione peroxidase (GPx), or their ratio could predict cognitive decline in people with DS over a 4-year period. Thirty-two adults with DS participated in a longitudinal study with SOD and GPx assays at baseline. Informants rated their functional ability and memory function at baseline and at 4 years follow-up. The more able adults with DS also completed assessments of language skills and memory, at two different time points 4 years apart. Twenty-six individuals with DS completed assessments of memory (Modified Memory Object Task, MOMT), adaptive behavior (ABAS), and receptive vocabulary (British Picture vocabulary, BPVS) at both time-points. SOD positively correlated with change on the MOMT score (r = 0.578, p = 0.015). There were no significant correlations between GPx level or SOD/GPx ratio and temporal changes in ABAS, BPVS, or MOMT scores. Our results suggest that SOD predicts memory decline over time and that these antioxidant enzymes could be a potential target for prevention of memory deterioration in adults with DS. Further research is required to test whether supplements which improve SOD function can also prevent cognitive decline. These findings may also have implications for prevention of cognitive decline in other groups which are at high risk of developing dementia, such as adults with familial AD or mild cognitive impairment.

Health care needs of children with Down syndrome and impact of health system performance on children and their families.

OBJECTIVE: The functional, financial, and social impact on families of children with Down syndrome (DS) in the United States and the role of the US health care system in ameliorating these impacts have not been well characterized. We sought to describe the demographic characteristics and functional difficulties of these children and to determine whether children with DS, compared with children with "intellectual disability" (ID) generally, and compared with other "children and youth with special health care needs" (CYSHCN), are more or less likely to receive health care that meets quality standards related to care coordination and to have their health care service needs met. METHODS: This study analyzed data from the 2005-2006 National Survey of Children with Special Health Care Needs (n = 40,723). Children and youth aged 0 to 17 years with special health care need (CYSHCN) who experience DS (n = 395) and/or IDs (n = 4252) were compared with each other and other CYSHCN on a range of functioning, family impact, and health care quality variables using bivariate and multivariate methods. Data were weighted to represent all CYSHCN in the United States. RESULTS: Compared with CYSHCN without DS, children with DS were significantly less likely to receive comprehensive care within a medical home (29.7% vs 47.3%; p < .001). Parents of children with DS were also significantly more likely to cut back or stop work due to their child's health needs (23.5% vs 55.1%; p < .001). Although overall system performance was poorer for children with DS compared with those with ID and no DS after adjustment for family income, prevalence on most aspects of quality of care and family impacts evaluated were similar for these 2 groups. CONCLUSIONS: In this study, the families of children with DS, and ID generally, are burdened disproportionately when compared with other CYSHCN, reflecting the combination of impairments intrinsic to DS and ID and impacts of suboptimal medical care coordination and social support.

Lack of maternal folic acid supplementation is associated with heart defects in Down syndrome: a report from the National Down Syndrome Project.

BACKGROUND: Maternal folic acid supplementation has been associated with a reduced risk for neural tube defects and may be associated with a reduced risk for congenital heart defects and other birth defects. Individuals with Down syndrome are at high risk for congenital heart defects and have been shown to have abnormal folate metabolism. METHODS: As part of the population-based case-control National Down Syndrome Project, 1011 mothers of infants with Down syndrome reported their use of supplements containing folic acid. These data were used to determine whether a lack of periconceptional maternal folic acid supplementation is associated with congenital heart defects in Down syndrome. We used logistic regression to test the relationship between maternal folic acid supplementation and the frequency of specific heart defects correcting for maternal race or ethnicity, proband sex, maternal use of alcohol and cigarettes, and maternal age at conception. RESULTS: Lack of maternal folic acid supplementation was more frequent among infants with Down syndrome and atrioventricular septal defects (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.08-2.63; p = 0.011) or atrial septal defects (OR, 1.69; 95% CI, 1.11-2.58; p = 0.007) than among infants with Down syndrome and no heart defect. Preliminary evidence suggests that the patterns of association differ by race or ethnicity and sex of the proband. There was no statistically significant association with ventricular septal defects (OR, 1.26; 95% CI, 0.85-1.87; p = 0.124). CONCLUSIONS: Our results suggest that lack of maternal folic acid supplementation is associated with septal defects in infants with Down syndrome. Birth Defects Research (Part A), 2011. © 2011 Wiley-Liss, Inc.

Direct health care costs of children and adolescents with Down syndrome.

OBJECTIVE: To assess the direct annual health care costs for children and adolescents with Down syndrome in Western Australia and to explore the variation in health care use including respite, according to age and disease profile. STUDY DESIGN: Population-based data were derived from a cross-sectional questionnaire that was distributed to all families who had a child with Down syndrome as old as 25 years of age in Western Australia. RESULTS: Seventy-three percent of families (363/500) responded to the survey. Mean annual cost was $4209 Australian dollars ($4287 US dollars) for direct health care including hospital, medical, pharmaceutical, respite and therapy, with a median cost of $1701. Overall, costs decreased with age. The decline in costs was a result of decreasing use of hospital, medical, and therapy costs with age. Conversely, respite increased with age and also with dependency. Health care costs were greater in all age groups with increasing dependency and for an earlier or current diagnosis of congenital heart disease. Annual health care costs did not vary with parental income, including cost of respite. CONCLUSIONS: Direct health care costs for children with Down syndrome decrease with age to approximate population costs, although costs of respite show an increasing trend.

Evaluation of C677T and A1298C polymorphisms of the MTHFR gene as maternal risk factors for Down syndrome and congenital heart defects.

Abnormal folate/homocysteine metabolism due to polymorphisms in genes involved in this pathway has been implicated as an etiologic factor in Down syndrome (DS). This case-control study aimed to evaluate the effect of maternal C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) as risk factors for the development of DS and congenital heart defects (CHD). The distribution of these genotypic variants was similar between mothers of children with DS (n = 239) and control mothers of normal children (n = 197), but the combined genotypes 677CT or TT and 1298AA increased the risk of having offspring with DS (OR = 1.99; 95% CI 1.11-3.55). The presence of the 677T allele in case mothers resulted in a 2.07-fold higher odds of CHD in the offspring (P < 0.01). Among the 57 mothers of CHD-affected children with DS who carried the MTHFR 677CT or TT genotypes and did not have periconceptional folic acid intake, we observed a 2.26-fold increased odds (95% CI 1.25-4.09) of having any CHD-affected child with DS. Our results show that MTHFR genetic polymorphisms may be involved in the etiology of DS in our population when controlling for age. We noted a borderline significant association for the C677T polymorphism (P = 0.05). Maternal 677T allele may be associated with an increased occurrence of CHD in children with DS and we anticipate that women who carry this polymorphism would benefit from periconceptional folic acid supplementation. (c) 2009 Wiley-Liss, Inc.

Periconceptional maternal vitamin supplementation and childhood leukaemia: an uncertainty analysis.

BACKGROUND: Recent studies in childhood cancer suggest that maternal vitamin supplementation may reduce the risk of leukaemia, neuroblastoma and certain types of childhood brain tumours. For example, a previous study found a significantly reduced risk of acute lymphoblastic leukaemia (ALL) but not acute myeloid leukaemia (AML) in children with Down syndrome whose mothers reported any vitamin supplement use prior to knowledge of pregnancy (ALL OR adjusted for confounders 0.51, 95% confidence limits (CL): 0.30, 0.89; AML OR adjusted for confounders 0.92, 95% CL 0.48, 1.76). Recall of exposures, including maternal vitamin supplement use, however, may be difficult and subject to error. Epidemiologists are encouraged to quantitatively adjust for systematic error in study results, but often do not. METHODS: The impact that misclassification of maternal vitamin supplement use may have had on the observed ORs in this study was quantified. Uncertainty analysis was used to calculate ORs adjusted for inaccurate reporting of vitamin supplement use under assumed probability distributions for exposure misclassification parameters. RESULTS: Given our assumptions, adjustment for exposure misclassification yielded ORs that were predominantly more protective for ALL than the crude OR. CONCLUSIONS: Uncertainty analysis can give important insights into the magnitude and direction of error in study results due to exposure misclassification.