Leukemia and other cancers, anomalies and infections as causes of death in Down's syndrome in the United States during 1976

Adults with Trisomy 21 Have Differential Antibody Responses to Influenza A

Down syndrome is caused by an extra copy of chromosome 21. In the past two decades, the life expectancy of individuals with Down syndrome has significantly increased from early 20s to early 60s, creating a population of individuals of which little is known about how well they are protected against infectious disease. The goal of this work is to better understand if adults with Down syndrome are well protected against influenza following vaccination. We obtained plasma samples from 18 adults (average age = 31yo) with Down syndrome and 17 age/gender-matched disomic individuals, all vaccinated against influenza. Antibody concentration to influenza A was measured using ELISA and antibody titers were measured using a hemagglutinin inhibition assay. Statistical analysis was performed using Stata Statistical Software. Adults with Down syndrome had a significantly increased concentration of antibodies to a mixture of influenza A viral proteins; however, they had a significantly decreased titer to the Influenza A/Hong Kong compared to disomic controls. These findings suggest that more vigorous studies of B- and T-cell function in adults with Down syndrome with respect to influenza vaccination are warranted, and that this population may benefit from a high-dose influenza vaccine.

Transcriptomic study in women with trisomy 21 identifies a possible role of the GTPases of the immunity-associated proteins (GIMAP) in the protection of breast cancer

BACKGROUND

People with trisomy 21 (T21) are predisposed to developing hematological tumors, but have significantly lower-than-expected age-adjusted incidence rates of having a solid tumor.

MATERIAL AND METHODS

To identify novel genetic factors implicated in the lower breast cancer (BC) frequency observed in women with T21 than in the general population, we compared the transcriptome pattern of women with a homogeneous T21, aged more than 30 years, with or without BC, and tumoral BC tissue of control women with a normal karyotype from the study of Varley et al. (2014).

RESULTS

Differential analysis of gene expression between the 15 women in the T21 without BC group and BC patients in the other groups (two women with T21 and fifteen control women, respectively) revealed 154 differentially expressed genes, of which 63 were found to have similar expression profile (up- or downregulated). Of those 63 genes, four were in the same family, namely GIMAP4, GIMAP6, GIMAP7 and GIMAP8, and were strongly upregulated in the T21 without BC group compared to the other groups. A significant decrease in mRNA levels of these genes in BC tissues compared to non-tumor breast tissues was also noted.

CONCLUSION

We found that the expression of some GIMAPs is significantly higher in women with T21 without BC than in patients with sporadic BC. Our findings support the hypothesis that GIMAPs may play a tumor-suppressive role against BC, and open the possibility that they may also have the same role for other solid tumors in T21 patients. The search for new prognostic factors and hopefully new therapeutic or preventive strategies against BC are discussed.

Effects of Pidotimod on recurrent respiratory infections in children with Down syndrome: a retrospective Italian study

BACKGROUND

Children with Down syndrome (DS) show a high susceptibility to recurrent infections (RI), caused by immune defects and abnormalities of the airways. Our goal was to investigate the effects of Pidotimod on RI prevention in children with DS, comparing immune and clinical parameters before (T0) and after (T1) the treatment with Pidotimod.

METHODS

The study was conducted at the Down syndrome outpatient Center of Bambino Gesù Children's Hospital, in Rome. We reviewed the medical records of all children with a positive history for RI and who received oral prophylaxis of Pidotimod from September 2016 to February 2017.

RESULTS

Thirty-three children met the inclusion criteria (males: 51.5%; average age: 6 years ±SD: 3). We found a significant decrease in the number of children with upper respiratory infections (82% at T0 vs 24% at T1; p = 0,0001) and with lower respiratory infections (36% at T0 vs 9% at T1; p = 0.003) after treatment with Pidotimod. We also demonstrated a significant decrease in the number of children hospitalized for respiratory infections (18% at T0 vs 3% at T1; p = 0.03). We measured T and B cells in the peripheral blood and B cell function in vitro at T0 and T1. We found that the response to CpG improved at T1. A significant increase of B cell frequency (p = 0.0009), B cell proliferation (p = 0.0278) and IgM secretion (p = 0.0478) were observed in children with DS after treatment.

CONCLUSIONS

Our results provided evidence that Pidotimod may be able to prevent RI in children with Down syndrome.

Selecting variants of unknown significance through network-based gene-association significantly improves risk prediction for disease-control cohorts

Variants of unknown/uncertain significance (VUS) pose a huge dilemma in current genetic variation screening methods and genetic counselling. Driven by methods of next generation sequencing (NGS) such as whole exome sequencing (WES), a plethora of VUS are being detected in research laboratories as well as in the health sector. Motivated by this overabundance of VUS, we propose a novel computational methodology, termed VariantClassifier (VarClass), which utilizes gene-association networks and polygenic risk prediction models to shed light into this grey area of genetic variation in association with disease. VarClass has been evaluated using numerous validation steps and proves to be very successful in assigning significance to VUS in association with specific diseases of interest. Notably, using VUS that are deemed significant by VarClass, we improved risk prediction accuracy in four large case-studies involving disease-control cohorts from GWAS as well as WES, when compared to traditional odds ratio analysis. Biological interpretation of selected high scoring VUS revealed interesting biological themes relevant to the diseases under investigation. VarClass is available as a standalone tool for large-scale data analyses, as well as a web-server with additional functionalities through a user-friendly graphical interface.

Down's Syndrome and Triple Negative Breast Cancer: A Rare Occurrence of Distinctive Clinical Relationship

Down’s syndrome (DS), the most common genetic cause of significant intellectual disability in children and adults is caused by the trisomy of either all or a part of human chromosome 21 (HSA21). Patients with DS mostly suffer from characteristic tumor types. Although individual patients of DS are at a higher risk for acute leukemia and testicular cancers, other types of solid tumors including breast cancers are mostly uncommon and have significantly lower-than-expected age-adjusted incidence rates. Except for an increased risk of retinoblastomas, and lymphomas, the risk of developing solid tumors has been found to be lower in both children and adults, and breast cancer was found to be almost absent (Hasle H., The Lancet Oncology, 2001). A study conducted in the United States found only one death when 11.65 were expected (Scholl T et al., Dev Med Child Neurol. 1982). A recent study examined mammogram reports of women with DS treated in the largest medical facility specifically serving adults with DS in the United States. It was found that only 0.7% women with DS had been diagnosed with breast cancers (Chicoine B et al., Intellect Dev Disabil. 2015). Here we describe a case of breast cancer in a 25-year-old patient with DS. The disease was presented as lymph node positive carcinoma with alterations of tumor suppressor genes characteristic to the triple negative breast cancer subtype. Comprehensive Genomic Profiling (CGP) revealed a wild-type status for BRCA1. The CGP report showed a frameshift mutation, A359fs*10 of the tumor suppressor gene INPP4B and another frameshift mutation, R282fs*63 of tumor suppressor gene TP53 in the tumor biopsy as characteristically found in triple-negative breast cancers. The VUS (Variance of Unknown Significance) alteration(s) were identified in ASXL1 (L1395V), NTRK1 (G18E), DDR2 (I159T), RUNX1 (amplification), ERG (amplification), SOX2 (T26A), FAM123B (G1031D), and HNF1A (A301T). Bonafide cancer-related genes of chromosome 21 amplified in the patient’s tumor are RUNX1 and ERG genes. After the completion of the radiation, the patient was placed on everolimus which was based on the result of her CGP report. Thus, post-mastectomy radiation therapy was completed with a recommendation for everolimus for one year. During the time of writing of this report, no metastatic lesions were identified. The patient currently has no evidence of disease.

Challenges in Diagnosis and Treatment of Lung Cancer in People with Intellectual Disabilities: Current State of Knowledge

As the life expectancy of people with intellectual disability (ID) has progressed, they have become similarly at risk of cancer as individuals of the general population. Epidemiological studies indicate a reduced incidence and mortality from lung cancer in the total population of persons with ID. However, the pattern is heterogeneous and the risk is strongly correlated with the impairment level; persons with mild intellectual impairment have higher cancer risk, and this subgroup also has the highest tobacco consumption (the major risk factor for lung cancer) compared to individuals with more severe impairment. Clinical presentation of lung cancer in persons with ID is often atypical, with symptoms frequently hidden by the mental state and communication impairments. Treatment can be impeded by incomplete understanding and lack of cooperation on the part of the patient; nevertheless, general principles for treating lung cancer must be applied to persons with ID. Early diagnosis and implementation of an adapted treatment plan may result in lung cancer outcomes similar to those of individuals in the general population. Physicians facing the difficult task of treating lung cancer in persons with ID are called to carry out their mission of care in a responsible, free, and creative way.

Intracerebral haemorrhage in Down syndrome: protected or predisposed?

Down syndrome (DS), which arises from trisomy of chromosome 21, is associated with deposition of large amounts of amyloid within the central nervous system. Amyloid accumulates in two compartments: as plaques within the brain parenchyma and in vessel walls of the cerebral microvasculature. The parenchymal plaque amyloid is thought to result in an early onset

Alzheimer’s disease (AD) dementia, a phenomenon so common amongst people with DS that it could be considered a defining feature of the condition. The amyloid precursor protein ( APP) gene lies on chromosome 21 and its presence in three copies in DS is thought to largely drive the early onset AD. In contrast, intracerebral haemorrhage (ICH), the main clinical consequence of vascular amyloidosis, is a more poorly defined feature of DS. We review recent epidemiological data on stroke (including haemorrhagic stroke) in order to make comparisons with a rare form of familial AD due to duplication (i.e. having three copies) of the APP region on chromosome 21, here called ‘dup-APP’, which is associated with more frequent and severe ICH. We conclude that although people with DS are at increased risk of ICH, this is less common than in dup-APP, suggesting the presence of mechanisms that act protectively. We review these mechanisms and consider comparative research into DS and dup-APP that may yield further pathophysiological insight.

Early postoperative outcomes following surgical repair of complete atrioventricular septal defects: is down syndrome a risk factor?

OBJECTIVE

To evaluate the impact of Down syndrome on the early postoperative outcomes of children undergoing complete atrioventricular septal defect repair.

DESIGN

Retrospective cohort study.

SETTING

Single tertiary pediatric cardiac center.

PATIENTS

All children admitted to PICU following biventricular surgical repair of complete atrioventricular septal defect from January 2004 to December 2009.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 107 children, 67 with Down syndrome, were included. Children with Down syndrome were operated earlier: 4 months (interquartile range, 3.5-6.6) versus 5.7 months (3-8.4) for Down syndrome and non-Down syndrome groups, respectively (p < 0.01). There was no early postoperative mortality. There was no significant difference in the prevalence of dysplastic atrioventricular valve between the two groups. Two children (2.9%) from Down syndrome and three children (7.5%) from non-Down syndrome group required early reoperation (p = 0.3). Junctional ectopic tachycardia was the most common arrhythmia, and the prevalence of junctional ectopic tachycardia was similar between the two groups (9% and 10% in Down syndrome and non-Down syndrome, respectively, p = 1). One patient from each group required insertion of permanent pacemaker for complete heart block. Children with Down syndrome had significantly higher prevalence of noncardiac complications, that is, pneumothorax, pleural effusions, and infections (p < 0.01), than children without Down syndrome. There was a trend for longer duration of mechanical ventilation in children with Down syndrome (41 hr [20-61 hr] vs 27.5 hr [15-62 hr], p = 0.2). However, there was no difference in duration of PICU stay between the two groups (2 d [1.3-3 d] vs 2 d [1-3 d], p = 0.9, respectively).

CONCLUSIONS

In our study, we found no difference in the prevalence of atrioventricular valve dysplasia between children with and without Down syndrome undergoing complete atrioventricular septal defect repair. This finding contrasts with previously published data, and further confirmatory studies are required. Although clinical outcomes were similar, children with Down syndrome had a significantly higher prevalence of noncardiac complications in the early postoperative period than children without Down syndrome.

Adenocarcinoma of the Lung in down Syndrome: First Clinical Report

Lung cancer is rare in persons with Down syndrome, and the clinical presentation of the disease has not been described in adults with intellectual disability. We report the first detailed clinical observation of a 33-year-old man with Down syndrome who developed an adenocarcinoma of the lung 30 years after an acute lymphoblastic leukemia in infancy. Despite advanced disease at initial presentation and extensive tumor spreading during the course of the disease, he presented with unusually mild symptoms. The scarcity of lung cancer in people with intellectual disability, and particularly those with Down syndrome, is due, in part, to reduced tobacco use. However, cytogenetic and molecular studies suggest that genes mapping to chromosome 21 may protect against lung cancer. Numerous reports also suggest that, in persons with Down syndrome and other intellectual disability, cancers are often discovered late, leading to loss of the chance of cure and recovery.

Tumorigenesis in Down's syndrome: big lessons from a small chromosome

If assessed by a number of criteria for cancer predisposition, Down's syndrome (DS) should be an overwhelmingly cancer-prone condition. Although childhood leukaemias occur more frequently in DS, paradoxically, individuals with DS have a markedly lower incidence of most solid tumours. Understanding the mechanisms that are capable of overcoming such odds could potentially open new routes for cancer prevention and therapy. In this Opinion article, we discuss recent reports that suggest unique and only partially understood mechanisms behind this paradox, including tumour repression, anti-angiogenic effects and stem cell ageing and availability.

Benign and malignant tumors in Down syndrome: analysis of the 1514 autopsied cases in Japan

BACKGROUND

Down syndrome is known for its association with neoplasms. The aim of this study was to examine this association.

METHODS

We surveyed the association with benign and malignant neoplasms in Down syndrome patients registered in the Annual of Pathological Autopsy Cases of Japan (1974-2000), a database of autopsied cases operated by the Japanese Society of Pathology.

RESULTS

In a total of 1514 cases with Down syndrome, there were eight cases with 10 benign tumors (four male and four female) and 104 cases with malignant disorders (61 male, 42 female and one case with unrecorded sex), in which 87 cases with hematopoietic malignancies (83.7%) and 17 cases with solid tumors (16.3%), were identified. The association of gallbladder adenocarcinoma with a benign tumor of the colon was noted in one case, while a further two cases with double benign tumors were confirmed as well. No case with a double malignancy was found. Hematopoietic malignancies (87 cases) included 31 cases (35.6%) with acute myelocytic leukemia, 10 (11.4%) with acute lymphocytic leukemia and two (2.3%) with chronic myelocytic leukemia. The ratio of acute myelocytic leukemia to acute lymphocytic leukemia was 3.1 in the present study. A peak in the age distribution was at 0 years in our data in contrast to the previous data (at 1 year) for myelocytic leukemia. The 17 solid tumors identified included three hepatocellular carcinomas, three extrahepatic cholangiocarcinomas, two gallbladder adenocarcinomas, three brain tumors, and three seminomas.

CONCLUSION

We present new associations of benign and malignant tumors with Down syndrome.

Carcinosarcoma of the uterus in a woman with Down syndrome

There are only a few reports of uterine cancers in women with Down syndrome, whose tumor profile is marked by a reduced risk for solid neoplasms. There are no reports of a uterine carcinosarcoma arising in a woman with Down syndrome. in our case, a delayed diagnosis of uterine carcinosarcoma was confirmed in a 38-year-old, nulliparous, single, obese woman with Down syndrome, who presented with irregular vaginal bleeding. Although uterine cancers are underrepresented in women with Down syndrome, uterine malignancy should be considered in the differential diagnosis of abnormal vaginal bleeding. A timely and complete gynecological examination will preclude a delay in diagnosis.

Distinct abnormalities in the innate immune system of children with Down syndrome

OBJECTIVE

To analyze the frequency and phenotype of cells of the innate immune system in the peripheral blood of children with Down syndrome (DS).

STUDY DESIGN

Flow cytometric analysis of expression of cell surface markers was performed in children with DS (n = 41) and healthy age-matched controls (n = 41).

RESULTS

Compared with controls, children with DS had significantly lower absolute total leukocyte counts, lymphocytes, monocytes, and granulocytes, but 1.5-times higher absolute numbers of CD14(dim)CD16(+) monocytes (147 x 10(6)/L vs 93 x 10(6)/L; P = .02). This difference is fully explained by a higher percentage of CD14(dim)CD16(+) monocytes within the monocyte compartment (28.7% vs 13.4%; P <.001). The absolute numbers of myeloid dendritic cells were lower in DS (13.8 x 10(6)/L vs 22.7 x 10(6)/L; P <.001). The numbers of plasmacytoid dendritic cells and natural killer cells were normal. Absolute numbers of invariant natural killer T cells were very low overall, but significantly lower in children with DS than in controls (1.2 x 10(6)/L vs 3.7 x 10(6)/L; P = .01).

CONCLUSIONS

Children with DS exhibited distinct abnormalities in cells of the innate immune system. Most strikingly, they had a high number of proinflammatory CD14(dim)CD16(+) monocytes. This elevated level of CD14(dim)CD16(+) monocytes may play an important role in the onset and maintenance of chronic inflammatory disease in DS.

Health conditions associated with aging and end of life of adults with Down syndrome

Expectations for the life course of individuals with Down syndrome (DS) have changed, with life expectancy estimates increasing from 12 in 1949 to nearly 60 years of age today (Bittles & Glasson, 2004; Penrose, 1949). Along with this longer life expectancy comes a larger population of adults with DS who display premature age-related changes in their health. There is thus a need to provide specialized health care to this aging population of adults with DS who are at high risk for some conditions and at lower risk for others. This review focuses on the rates and contributing factors to medical conditions that are common in adults with DS or that show changes with age. The review of medical conditions includes the increased risk for skin and hair changes, early onset menopause, visual and hearing impairments, adult onset seizure disorder, thyroid dysfunction, diabetes, obesity, sleep apnea and musculoskeletal problems. The different pattern of conditions associated with the mortality of adults with DS is also reviewed.

Autologous stem cell transplant in a patient with Down syndrome and relapsed Hodgkin lymphoma

Children with Down syndrome (DS) are at increased risk for the development of acute leukemia but they rarely develop other hematologic malignancies or solid tumors. Despite aggressive supportive care, DS patients have increased risk of treatment related morbidity and mortality compared to other children. There are few reported cases of Hodgkin disease in children with DS, and no reported cases of successful therapy for patients with relapsed disease. We report on a child with DS and relapsed Hodgkin disease who was successfully treated with high-dose chemotherapy and autologous stem cell transplant.

Maternal health conditions during pregnancy and acute leukemia in children with Down syndrome: A Children's Oncology Group study

BACKGROUND

Children with Down syndrome (DS) have about a 20-fold increased risk of developing leukemia. Early childhood infections may protect against acute lymphoid leukemia (ALL) in children with and without DS. We examined whether maternal infections and health conditions during pregnancy were associated with acute leukemia in children with DS.

PROCEDURE

We conducted a case-control study of 158 children with DS and leukemia (including 97 cases with acute lymphoblastic leukemia (ALL) and 61 cases with acute myeloid leukemia (AML)) and 173 children with DS during the period 1997-2002. Maternal interview included information about 14 maternal conditions during gestation that are likely to induce an inflammatory response. We evaluated their prevalence in cases and controls. Five of these were common enough to allow analyses by leukemia subtype.

RESULTS

Vaginal bleeding was the most frequent (18% cases, 25% controls) and was associated with a reduced risk (odds ratio (OR) = 0.57; 95% confidence interval (CI) = 0.33-0.99) for all cases combined. Other variables, while showing a potential trend toward reduced risk had effect estimates, which were imprecise and not statistically significant. In contrast, amniocentesis was marginally associated with an increased risk of AML (OR = 2.06, 95% CI = 0.90-4.69).

CONCLUSIONS

Data from this exploratory investigation suggest that some health conditions during pregnancy may be relevant in childhood leukemogenesis. Larger epidemiological studies and other model systems (animal, clinical studies) may provide a clearer picture of the potential association and mechanisms.

Cerebral amyloid angiopathy-related hemorrhage in a middle-aged patient with Down's syndrome

A patient with Down's syndrome (DS) died of cerebral hemorrhage at age 52. At autopsy, a large sub-cortical hematoma was present in the right frontal lobe, and microscopic examination showed numerous senile plaques and neurofibrillary tangles in an extensive area of neocortex and also disclosed heavy involvement of vascular walls by amyloid deposition. These senile plaque and vascular amyloid deposits were specifically stained with an antibody to Abeta. His APOE genotype was epsilon4/epsilon4. This is a rare case of DS with cerebral amyloid angiopathy (CAA)-related cerebral hemorrhage. Genetic factors, such as APOE genotype, conceivably determine the risk of vascular rupture in individuals with CAA, even among patients with DS.

Congenital abnormalities and acute leukemia among children with Down syndrome: a Children's Oncology Group study

Children with Down syndrome, due to their heightened risk of leukemia and increased prevalence of congenital abnormalities, comprise a valuable population in which to study etiology. A Children's Oncology Group study investigated the causes of childhood leukemia in children with Down syndrome diagnosed at ages 0 to 19 years during the period 1997-2002. Telephone interviews were completed with mothers of 158 cases [n=97 acute lymphoblastic leukemia (ALL) and n=61 acute myeloid leukemia (AML)] and 173 controls. Odds ratios (OR) and 95% confidence intervals (95% CI) were computed via unconditional logistic regression to evaluate the association between congenital abnormalities and acute leukemia overall, and ALL and AML analyzed separately. The results do not provide evidence for an association among the index children (OR(Combined), 0.74; 95% CI, 0.45-1.23; OR(ALL), 0.67; 95% CI, 0.38-1.20; OR(AML),1.03; 95% CI, 0.49-2.16) or their siblings (OR(Combined), 1.23; 95% CI, 0.71-2.13; OR(ALL), 1.12; 95% CI, 0.60-2.09; OR(AML), 1.60; 95% CI, 0.66-3.86), suggesting congenital malformations do not confer additional risk of leukemia beyond the risk attributable to trisomy 21 in this population.

Down syndrome: a novel risk factor for respiratory syncytial virus bronchiolitis--a prospective birth-cohort study

OBJECTIVES

Respiratory syncytial virus is the single-most important cause of lower respiratory tract infections in children. Preterm birth and congenital heart disease are known risk factors for severe respiratory syncytial virus infections. Although Down syndrome is associated with a high risk of respiratory tract infections, little is known about the incidence of respiratory syncytial virus infections in this group. The aim of our study was to determine the incidence of respiratory syncytial virus lower respiratory tract infection-associated hospitalization among children with Down syndrome.

PATIENTS AND METHODS

We performed a retrospective observational study and a prospective nationwide birth-cohort study of children with Down syndrome. The retrospective cohort comprised 176 children with Down syndrome. A birth cohort of 219 children with Down syndrome was prospectively followed until 2 years of age. All 276 siblings of the birth cohort were used as controls.

RESULTS

Of the 395 patients with Down syndrome, 180 (45.6%) had a known risk factor for severe respiratory syncytial virus infections; 39 (9.9%) of these were hospitalized for respiratory syncytial virus lower respiratory tract infections. Two control children (0.7%) versus 9 term children with Down syndrome without congenital heart disease (7.6%) were hospitalized for respiratory syncytial virus lower respiratory tract infections. The median duration of hospitalization was 10 days; mechanical ventilation was required for 5 children (12.8%).

CONCLUSIONS

This is the first study, to our knowledge, to demonstrate that Down syndrome is a novel independent risk factor for severe respiratory syncytial virus lower respiratory tract infections. These findings should prompt studies to investigate possible mechanisms that underlie severe respiratory syncytial virus lower respiratory tract infections in children with Down syndrome. The effect of respiratory syncytial virus prophylaxis in this specific population needs to be established.

Forensic issues in Down syndrome fatalities

Down syndrome, or trisomy 21, is the most common chromosomal abnormality associated with intellectual impairment. Premature death is a feature of the syndrome due to a wide variety of conditions including congenital heart disease, impaired immune responses resulting in respiratory infections, acute leukaemia, upper airway narrowing, pulmonary hypertension, Alzheimer disease and atlantoaxial instability. Cases of Down syndrome not uncommonly present for medicolegal autopsy, as the non-specificity of symptoms and signs often precludes accurate antemortem establishment of a cause of death. Manifestations of Down syndrome are reviewed with an analysis of possible mechanisms of death and findings at autopsy.

The profile and incidence of cancer in Down syndrome

BACKGROUND

Down syndrome is one of the commonest causes of intellectual disability. As life expectancy improves with early and more intensive surgical and medical treatments, people with the disorder are more likely to exhibit classic morbidity and mortality patterns and be diagnosed with diseases such as cancer.

METHODS

A profile of cancer cases among people with Down syndrome has been compiled, based on the analysis of a linked data set that included information from the Disability Services Commission of Western Australian and the State Cancer Registry.

RESULTS AND CONCLUSIONS

Although the total age- and sex-standardized incidence ratios (SIRs) for people with Down syndrome were similar to that for the general population, SIRs for leukaemia were significantly higher while the incidence of certain other types of cancers was reduced. Overall, there was a lower incidence of solid tumours in Down syndrome, possibly reflecting the age profile of the study cohort.

Down syndrome and acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia in children with Down syndrome (ALL-DS) is characterised by unique clinical and biological features. Notable among these are an absence of ALL in DS patients <1 year of age; a lower incidence of favourable and unfavourable chromosomal translocations; heightened sensitivity to methotrexate; and an increased propensity to infections. Although children with ALL-DS have historically fared less well than their non-DS counterparts (ALL-NDS), recent data indicate that outcomes in ALL-DS are now comparable with ALL-NDS with risk-adapted therapies, after adjusting for biological differences between the ALL-DS and ALL-NDS populations. Given the increased risk of ALL-DS patients for treatment-related toxicities, further intensification of therapy may not yield continued improvements in survival. Future investigations in the ALL-DS population should focus on maintaining excellent outcomes while reducing treatment-related complications through novel treatment strategies, such as the integration of targeted noncytotoxic agents.

Exposure to medical test irradiation and acute leukemia among children with Down syndrome: a report from the Children's Oncology Group

OBJECTIVE

The etiology of acute childhood leukemia is not well understood, particularly among children with Down syndrome, in whom a 10- to 20-fold increased risk of leukemogenesis has been reported compared with children without Down syndrome. We explored the association between medical test irradiation, a postulated leukemogenic agent, and acute leukemia among children with Down syndrome.

PATIENTS AND METHODS

Children with Down syndrome (controls) were frequency matched on age to children with Down syndrome and leukemia (cases) diagnosed at ages 0 to 19 years during the period 1997-2002 at participating Children's Oncology Group institutions in North America. Telephone interviews were completed with mothers of 158 cases (n = 97 acute lymphoblastic leukemia and n = 61 acute myeloid leukemia) and 173 controls. Paternal interviews were completed with 275 fathers and 40 mothers serving as surrogates. Three irradiation exposure periods were examined: preconception, in utero, and postnatal. Multivariate unconditional logistic regression models were constructed to evaluate the associations of interest, resulting in odds ratios and 95% confidence intervals.

RESULTS

There was little evidence that maternal or paternal preconception irradiation exposure, intrauterine exposure, or postnatal exposure contributes to leukemogenesis in children with Down syndrome. Overall, no evidence for an effect of any periconceptional exposure was observed. Similar results were observed among acute lymphoblastic leukemia and acute myeloid leukemia cases analyzed separately.

CONCLUSIONS

This was the first study, to our knowledge, to examine such an association among this unique patient population. The results do not provide evidence of a positive association between ionizing radiation exposure and acute leukemia among children with Down syndrome. The absence of an association should be encouraging for concerned parents of children with Down syndrome who undergo a series of diagnostic radiographs in the course of their standard care.

Aspects of digestive tract tumors in Down syndrome: a literature review

The purpose of this study was to describe the digestive neoplasms found in persons with Down syndrome. Due to intellectual disability, persons with Down syndrome do not convey their symptoms and pain, leading to delayed diagnosis and potentially worse outcome. It is thus important to know which organs are at risk for tumors and possible tumor risk factors. In a review of the literature, we found 13 benign tumors and 127 cancers in 1 fetus, 8 children, and 131 adults with Down syndrome. The review suggests a decreased incidence of digestive cancer, however, with a possible increased incidence of neoplasms of the pancreas and gallbladder. The distribution of cancers is distinct from that in the general population and that in persons with other intellectual disabilities who share the same life conditions, suggesting that constitutional protective factors exist. This review may allow a more specific, adapted medical follow-up for persons with Down syndrome and could help to elucidate the oncogenesis of digestive neoplasms.

An ovarian dysgerminoma in Down syndrome. Hypothesis about the association

An 11-year-old girl with Down syndrome (DS) was operated for a stage I right ovary dysgerminoma. She is in good health 33 years later. Some data in the literature suggest that ovarian cancers could be slightly overrepresented in DS. Despite the rarity of ovarian dysgerminoma, our case is the fifth reported in DS. This case is the second one associated with a family history suggesting the possibility of a familial predisposition to cancer. A hypothesis explaining the development of dysgerminoma in DS is proposed.

Decreased level of T cell receptor expression by Down syndrome (trisomy 21) thymocytes

Individuals with Down syndrome (DS) have an enhanced susceptibility to viral and bacterial infections. Previous studies by our laboratory demonstrated alterations in the proportions of peripheral T cell subpopulations and decreased proliferative, interleukin-2, and antibody responses to viral and bacterial antigens in DS. These data suggested that DS lymphocytes have a diminished ability to recognize and respond to specific antigen. It has been proposed that the abnormalities in T cell function in DS may be a result of aberrant T cell maturation within the DS thymus. Therefore, we examined by immunofluorescence and flow cytometry the cell surface expression of the alpha,beta chains of the T cell receptor (TCR alpha,beta) and the associated CD3 molecule on thymocytes from 10 DS and 27 control children. A significantly smaller proportion of cells expressing high levels of TCR alpha,beta was observed in DS thymuses compared to controls (17.0% vs. 34.3%, respectively; P less than 0.01). A similar observation was made for CD3, a molecule responsible for signal transduction through the TCR, where a lower proportion of cells expressing high levels of CD3 was found in DS compared to controls (18.4% vs. 43.3%, respectively; P less than 0.001). These data are evidence for aberrant T cell maturation in DS. In addition, our findings of decreased acquisition of high levels of the molecules which are critical for antigen-specific recognition by T cells suggest a possible mechanism for the decreased T cell function found in individuals with DS.

Childhood and maternal infections and risk of acute leukaemia in children with Down syndrome: a report from the Children's Oncology Group

Children with Down syndrome (DS) are highly susceptible to acute leukaemia. Given the potential role of infections in the aetiology of leukaemia in children without DS, we investigated whether there was an association between early-life infections and acute leukaemia in children with DS. Maternal infections during pregnancy were also examined. We enrolled 158 incident cases of acute leukaemia in children with DS (97 acute lymphoblastic leukaemia (ALL) and 61 acute myeloid leukaemia (AML)) diagnosed at Children's Oncology Group institutions between 1997 and 2002. DS controls (N=173) were selected from the cases' primary care clinics and frequency matched on age at leukaemia diagnosis. Data were collected on demographics, child's medical history, mother's medical history, and other factors by maternal interview. Analyses were conducted using unconditional logistic regression adjusted for potential confounders. A significant negative association was observed between acute leukaemia and any infection in the first 2 years of life (adjusted odds ratio (OR)=0.55, 95% confidence interval (CI) (0.33–0.92); OR=0.53, 95% CI (0.29–0.97); and OR=0.59, 95% CI (0.28–1.25) for acute leukaemia combined, ALL, and AML respectively). The association between acute leukaemia and maternal infections during pregnancy was in the same direction but not significant. This study offers support for the hypothesis that early-life infections may play a protective role in the aetiology of acute leukaemia in children with DS.

A Low-Grade Follicular Thyroid Carcinoma in a Woman with down Syndrome

Aims

Analysis of a thyroid neoplasm in a person with Down syndrome.

Method

Report of a case and review of the literature.

Results

A 34-year-old woman with Down syndrome developed a right thyroid low-grade follicular carcinoma. She is alive 20 years after the discovery of the initial tumor. A review of the literature including epidemiological studies revealed only one unspecified cancer, one papillary carcinoma and one lymphoma. Persons with Down syndrome present an excess of goiter and thyroiditis and often are overweight and have low serum selenium, all these conditions being risk factors for thyroid carcinomas.

Conclusion

Thyroid malignant neoplasms are very rare in persons with Down syndrome. We suspect that some constitutional, hormonal and genetic factors could protect these subjects against thyroid carcinoma.

Parotid salivary immunoglobulins, recurrent respiratory tract infections and gingival health in institutionalized and non-institutionalized subjects with Down's syndrome

BACKGROUND

The purpose of the present study was to evaluate the possible correlation between recurrent respiratory infections (RRIs), gingival health and the secretion rates of salivary immunoglobulins (Igs) in institutionalized (I) and non-institutionalized (NI) individuals with Down's syndrome (DS).

METHODS

Stimulated parotid saliva was collected from nine I and 14 NI subjects with DS. Salivary flow rate, secretion rates of total salivary IgM, IgG and IgA, and the incidence of RRIs were determined. Gingival health was recorded by using the plaque index, the gingival index and the percentage of bleeding surfaces (BS).

RESULTS

The mean salivary flow rate and parotid Ig secretion rates in the I group were 25% of those of the NI group. The prevalence of RRIs in the I group was more than twice that in the NI group. Oral hygiene and gingival health were significantly better in the NI group.

CONCLUSIONS

The lower parotid Ig secretion rates in I individuals with DS might be a possible factor involved in their susceptibility to recurrent infections compared to NI subjects with DS.

A link between parotid salivary Ig level and recurrent respiratory infections in young Down's syndrome patients

The purpose of the present investigation was to assess the correlation between recurrent respiratory infections and the levels of salivary Ig in a group of young Down's syndrome (DS) individuals. Twenty-three DS and 10 age- and sex-matched healthy individuals were included. DS individuals who had experienced three or more upper respiratory tract infections (n = 10) in the previous 12 months were compared to DS individuals who had not experienced recurrent respiratory infections (n = 13) and to healthy controls (n = 10). A statistically significant reduction in the Ig salivary secretion rate was recorded in the subgroup with recurrent respiratory infections. No significant differences were seen between the subgroup without recurrent respiratory infections and controls. It is suggested that the secretory immune system provides local immune protection against pathogens in the respiratory tract. Detection of salivary Ig levels may serve as a predictor of the susceptibility of DS individuals to recurrent respiratory tract infections.

Mortality associated with Down's syndrome in the USA from 1983 to 1997: a population-based study

BACKGROUND

Down's syndrome is the most frequently identified cause of mental retardation, but information about mortality and comorbidity in people with Down's syndrome is limited.

METHODS

We used data from US death certificates from 1983 to 1997 to calculate median age at death and standardised mortality odds ratios (SMORs) for common medical disorders in people with Down's syndrome.

FINDINGS

Of 17897 people reported to have Down's syndrome, median age at death increased from 25 years in 1983 to 49 years in 1997, an average increase of 1.7 years per year studied (p<0.0001). Median age at death was significantly lower in black people and people of other races than in white people with Down's syndrome. As expected, death certificates with a diagnosis of Down's syndrome were more likely to list congenital heart defects (SMOR 29.1, 95% CI 27.8-30.4), dementia (21.2, 19.6-22.7), hypothyroidism (20.3, 18.5-22.3), or leukaemia (1.6, 1.4-1.8) than were those that did not report Down's syndrome. By contrast, malignant neoplasms other than leukaemia were listed on death certificates of people with Down's syndrome less than one-tenth as often as expected (0.07, 0.06-0.08). A strikingly low SMOR for malignancy was associated with Down's syndrome at all ages, in both sexes, and for all common tumour types except leukaemia and testicular cancer.

INTERPRETATION

Identification of factors responsible for the racial differences recorded could facilitate further improvement in survival of people with Down's syndrome. Reduced exposure to environmental factors that contribute to cancer risk, tumour-suppressor genes on chromosome 21, or a slower rate of replication or higher likelihood of apoptosis in Down's syndrome cells, could be possible reasons for paucity of cancer in people with Down's syndrome.

Respiratory syncytial virus infections in the pediatric intensive care unit: clinical characteristics and risk factors for adverse outcomes

OBJECTIVES

To describe the clinical characteristics of infants admitted to a pediatric intensive care unit (PICU) with respiratory syncytial virus (RSV) infection, including the prevalence of indications for RSV passive antibody prophylaxis (as currently recommended by the American Academy of Pediatrics), and to identify risk factors that predict adverse outcomes among this population.

DESIGN

Retrospective medical record review.

SETTING

Tertiary care PICU.

PATIENTS

Children <2 yrs of age admitted to PICU for the management of RSV disease during the 1994-95, 1995-96, and 1996-97 RSV seasons.

MEASUREMENTS AND MAIN RESULTS

The medical records of 89 infants were reviewed. Of these, 55% were born before 36-wks gestation, 14% had chronic lung disease that required medical therapy within the previous 6 months, and 30% met at least one indication for RSV passive antibody prophylaxis. Seven infants had congenital heart disease, five had upper airway abnormalities, and six had various noncardiac congenital malformations. Logistic regression was used to determine which characteristics were associated with prolonged durations (>75th percentile) of mechanical ventilation, PICU stay, and hospital stay. Prolonged mechanical ventilation was associated with congenital heart disease (p = 0.014), chronic lung disease (p = 0.007), and noncardiac congenital malformations (p = 0.022). Only congenital heart disease was associated with prolonged PICU stay (p = 0.004) or prolonged hospital stay (p = 0.006). All of the infants with airway abnormalities had prolonged ventilator days, PICU days, and hospital days. Currently recommended indications for RSV passive antibody prophylaxis were not predictive of prolonged ventilation, PICU stay, or hospital stay.

CONCLUSIONS

A minority of infants admitted to our PICU for severe RSV disease meet currently recommended indications for RSV passive antibody prophylaxis. Risk factors that predict prolonged durations of ventilation, PICU stay, or hospital stay among this population include congenital heart disease, chronic lung disease, upper airway abnormalities, and noncardiac congenital malformations.

Pattern of malignant disorders in individuals with Down's syndrome

The pattern of occurrence of malignant disorders in people with Down's syndrome (DS) is unique and may serve as a model in the search for leukaemogenic genes and tumour suppressor genes on chromosome 21, since the risk of leukaemia is higher in individuals with DS than in non-DS individuals. Acute lymphoblastic leukaemia in DS shares many of the clinical characteristics of the same malignancy in other patients, and with current intensive therapy the long-term survival is similar. Myelodysplastic syndrome and acute myeloid leukaemia have unique clinical characteristics in these patients and are best described as a single disorder, termed myeloid leukaemia of DS. When these patients are treated intensively, they show better survival rates than patients without DS. This may be related to increased expression of genes on chromosome 21 contributing to increased chemosensitivity. Chronic myeloid leukaemia and chronic lymphocytic leukaemia occur less often than expected. With the exception of an increased risk of retinoblastoma, germ-cell tumours, and perhaps lymphomas, the risk of developing solid tumours is lower in both children and adults. Breast cancer is almost absent, and the risk of a second malignant disease after treatment for leukaemia also appears to be decreased. Increased susceptibility to apoptosis in DS may result in cell death rather than malignant transformation after major cell injuries. This hypothesis would explain the decreased risk of both solid tumours and secondary cancers.

Risks of leukaemia and solid tumours in individuals with Down's syndrome

BACKGROUND

Individuals with Down's syndrome have a greater risk of leukaemia than the general population, but reliable estimates of the age-specific risk are lacking and little is known about the risk of solid tumours.

METHODS

We identified 2814 individuals with Down's syndrome from the Danish Cytogenetic Register, and linked the data to the Danish Cancer Registry. The number of person-years at risk was 48453. Standardised incidence ratio (SIR) and 95% CI were calculated of the basis of cancer rates specific for age and sex in the general population.

FINDINGS

60 cases of cancer were found, with 49.8 expected (SIR 1.20 [95% CI 0.92-1.55]). Leukaemia constituted 60% of cases of malignant disease overall and 97% of cases in children. The SIR for leukaemia varied with age, being 56 (38-81) at age 0-4 years and 10 (4-20) at 5-29 years. No cases of leukaemia were seen after the age of 29 years. The SIR for acute myeloid leukaemia was 3.8 (1.7-8.4) times higher than that for acute lymphoblastic leukaemia in children aged 0-4 years. The cumulative risk for leukaemia by the age of 5 years was 2.1% and that by 30 years was 2.7%. Only 24 solid tumours were seen, with 47.8 expected (0.50 [0.32-0.75]). No cases of breast cancer were found, with 7.3 expected (p=0.0007). Higher than expected numbers of testicular cancers, ovarian cancers, and retinoblastomas were seen but were not significant. INTREPRETATION: The occurrence of cancer in Down's syndrome is unique with a high risk of leukaemia in children and a decreased risk of solid tumours in all age-groups. The distinctive pattern of malignant diseases may provide clues in the search for leukaemogenic genes and tumour-suppressor genes on chromosome 21.

Increased levels of mutagen-induced chromosome breakage in Down syndrome children with malignancy

Even though an association between Down syndrome (DS) and malignancies has been established, the mechanism behind this is still unclear. We therefore investigated constitutional chromosomal abnormalities and bleomycin-induced chromosome sensitivity in 12 DS children, 8 DS children with malignancies, and 10 normal controls to explore whether these factors play any role in cancer predisposition. Trisomy 21 was the only constitutional cytogenetic abnormality observed in all the DS children. But there was significant variation between the patients and controls with regard to bleomycin sensitivity. Compared to the normal controls, all the DS patients expressed significantly higher chromosomal breaks per cell (b/c) values indicating sensitivity to bleomycin. Furthermore, DS children with malignancies demonstrated significantly higher b/c values than DS children with malignancies. These results permit us to assume that DS children showing mutagen hypersensitivity may be having defective DNA repair competence and hence may be predisposed to malignancies.