Urological Manifestations of Down Syndrome

Giftedness and atypical sexual differentiation: enhanced perceptual functioning through estrogen deficiency instead of androgen excess

Syndromic autism spectrum conditions (ASC), such as Klinefelter syndrome, also manifest hypogonadism. Compared to the popular Extreme Male Brain theory, the Enhanced Perceptual Functioning model explains the connection between ASC, savant traits, and giftedness more seamlessly, and their co-emergence with atypical sexual differentiation. Overexcitability of primary sensory inputs generates a relative enhancement of local to global processing of stimuli, hindering the abstraction of communication signals, in contrast to the extraordinary local information processing skills in some individuals. Weaker inhibitory function through gamma-aminobutyric acid type A (GABAA) receptors and the atypicality of synapse formation lead to this difference, and the formation of unique neural circuits that process external information. Additionally, deficiency in monitoring inner sensory information leads to alexithymia (inability to distinguish one's own emotions), which can be caused by hypoactivity of estrogen and oxytocin in the interoceptive neural circuits, comprising the anterior insular and cingulate gyri. These areas are also part of the Salience Network, which switches between the Central Executive Network for external tasks and the Default Mode Network for self-referential mind wandering. Exploring the possibility that estrogen deficiency since early development interrupts GABA shift, causing sensory processing atypicality, it helps to evaluate the co-occurrence of ASC with attention deficit hyperactivity disorder, dyslexia, and schizophrenia based on phenotypic and physiological bases. It also provides clues for understanding the common underpinnings of these neurodevelopmental disorders and gifted populations.

Primary membranoproliferative glomerulonephritis in a child with down syndrome complicated with CVA: A case report

Introduction

Down syndrome (DS) is a genetic disorder that affects multiple organs but glomerular lesions were reported only in case reports such as focal segmental glomerulosclerosis (FSGS), and Membranoproliferative glomerulonephritis (MPGN).

Case presentation

A 14-year-old male child with DS was presented with generalized edema over three months. Laboratory tests revealed nephrotic syndrome (NS) and urinary tract infection (UTI). Renal ultrasound consisted with CKD. Kidney biopsy corresponded with MPGN. Also, all investigations for secondary underlying disorders came back negative suggesting the idiopathic form. Moreover, the status complicated with cerebrovascular accident (CVA), which has not been described in a DS- patient with glomerulonephritis.

Discussion/conclusion

The relationship between DS and the incidence of glomerulonephritis is unclear. we suggest regular monitoring of renal function and urinalysis in different-age patients with Down syndrome, because early detection of renal disorders may prevent or slow down the progression and could be beneficial for increasing survival.

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Glomerulonephritis (GN) in the context of Down syndrome (DS) were only reported in case reports.

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A child with DS presented with nephrotic syndrome, CKD and the status complicated with CVA.

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Causal relationship between immunologic disorders in DS and the incidence of GN is unclear.

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This case supports the incidence of GN in different-age patients of DS.

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We suggest monitoring of renal function and urinalysis in patients of DS to early detect of renal disorders.

Global, Regional, and National Burden and Trends of Down Syndrome From 1990 to 2019

Introduction: Down syndrome (DS) is the leading cause of genetically defined intellectual disability and congenital birth defects worldwide. A large population of people diagnosed with DS globally is posing an enormous socioeconomic burden. However, the global burden and trends of DS have not been reported.

Methods: Based on the data from the Global Burden of Disease database in 2019, we analyzed the incidence, prevalence, disability-adjusted life years (DALYs), and death of DS from 1990 to 2019 according to sex, age, regions, and social-demographic index (SDI). Then, age-standardized rates (ASRs) and estimated annual percentage change (EAPC) of these aforementioned indexes were calculated to evaluate the temporal trend of DS. Finally, the association of SDI with DS epidemiological parameters was assessed.

Results: In the past 30 years, the incident cases, age-standardized incident rate (ASIR), and age-standardized prevalent rate (ASPR) of DS first decreased slightly and subsequently increased globally. The number of prevalent cases increased steadily, while the number and age-standardized rate (ASRs) of DALYs and deaths decreased gradually from 1990 to 2019. In the meantime, disease burdens were different across various SDI regions. The prevalent cases and ASPR for both sexes were increasing in all SDI regions except for the high-middle SDI region. At the national level, Brunei Darussalam, Ireland, and Haiti were the top three countries with the highest ASIR in 2019. Georgia was in the top three with the highest increase in ASRs of four parameters, while Serbia was consistently ranked in the top three with fastest declining. Furthermore, we found that ASIR and ASPR were positively correlated with SDI, yet the age-standardized DALYs and age-standardized death rate (ASDR) were negatively correlated with SDI.

Conclusion: In the past 30 years, the burden and trends of DS were heterogeneous across different regions and countries with different sociodemographic characteristics. Great improvements had been achieved in reducing DALYs and deaths globally. However, the increased number and ASRs of incident and prevalent cases in some regions, especially in low SDI regions, were contributing to numerous challenges to public health. The findings may provide valuable information to the development or implementation of more effective measures.

Endocrinal dysfunction in children with Down syndrome

Down syndrome (DS) is the most common genetic disorder in live-born infants. Children with DS are at increased risk of numerous endocrinal comorbidities. The information contained in this article will provide pediatricians with a narrative overview of different presentations, diagnoses, and management recommendations of various endocrinal disorders in children with DS. We systematically searched PubMed, Embase, Google Scholar, MEDLINE, EBSCO, and Science Direct, and potentially relevant articles were identified and retrieved from electronic and print journals.

Spontaneous bladder rupture secondary to posterior urethral valves in a boy with Down syndrome

We describe a case of a 3-year-old boy with Down syndrome who developed a bladder rupture as a consequence of an undiagnosed posterior urethral valve (PUV). He had a history of urinary tract infections and constipation and was acutely admitted in poor condition and underwent laparotomy that revealed peritoneal sepsis secondary to bladder perforation. Bladder was drained using a suprapubic catheter and the condition of the boy gradually improved. Once stable, a cystourethroscopy confirmed the presence of PUV. Video-urodynamic studies performed at the check cystoscopy showed the bladder to be of reduced compliance (end fill pressure at 100 mL fill 30 cmH2O) with raised voiding pressures (76-100 cmH2O) and significant incomplete bladder emptying. Currently, the patient is doing very well, serum creatinine has normalised, he is infection-free and thriving; his bladder is managed with a vesicostomy.

Podocyte Injury Through Interaction Between Tlr8 and Its Endogenous Ligand miR-21 in Obstructed and Its Collateral Kidney

While chronic kidney disease is prevalent in adults, obstructive nephropathy (ON) has been reported in both young and old patients. In ON, tubulointerstitial lesions (TILs) have been widely investigated, but glomerular lesions (GLs) have been largely neglected. Here, we show a novel mechanism underlying GL development in ON in young and old mice. TILs develop earlier than GLs owing to infiltration of inflammatory cells in the tubulointerstitium, but GLs develop following the activation of Toll-like receptor 8 (Tlr8) even though the absence of inflammatory cells infiltrating the glomerulus. TLR8 and interleukin 1 beta (IL1β) proteins colocalize with reducing podocyte function markers (PFMs), indicating the activation of TLR8 signaling in injured podocytes. Furthermore, glomerular and serum levels of miR-21, an endogenous ligand for Tlr8, were higher in the ON mouse model than in the sham control. The glomerular expression of Tlr8 positively correlates with miR-21 and the downstream cytokines Il1b and Il6 and negatively correlated with PFMs (Nphs1 and Synpo). We also show the colocalization of TLR8 and IL1β proteins with reducing PFMs in both obstructed and collateral kidney of young and old mice. Furthermore, in vitro study results revealed higher expression of Tlr8 and its downstream cytokines in glomeruli from obstructed kidneys following treatment with miR-21 mimic than in the control. In conclusion, the overexpression of Tlr8 may serve as a plausible mechanism underlying GL development in ON through podocyte injury.

Vemurafenib Treatment of Pleomorphic Xanthoastrocytoma in a Child With Down Syndrome

Brain tumors are the most common solid neoplasms of childhood, but they are very rarely reported in children with Down Syndrome (DS), who develop more commonly different types of malignancies. In particular, we hereby report the case of an 8-years-old child with DS that presented to our attention for neurological and endocrinological issues. Brain imaging revealed the presence of a mass that was partially resected revealing a histological diagnosis of Pleomorphic Xanthoastrocytoma (PXA), a rare WHO grade II tumor extending from the diencephalic region into the surrounding brain tissue. These tumors can harbor the BRAF mutation p.V600E, targetable by the specific inhibitor Vemurafenib. After confirming the presence of the mutation in the tumor, the patient was treated with Vemurafenib. The treatment proved to be effective, leading to a partial response and a stabilization of the disease. Usually, in patients with DS a reduction of the dose of chemotherapeutic drugs is necessary. Vemurafenib was instead well-tolerated as the only observed adverse effect was grade I skin toxicity. This is, to our knowledge, the first case of a PXA reported in a child with DS and the first DS patient treated with Vemurafenib.

End-stage renal disease in a Down syndrome patient caused by delayed diagnosis of nonneurogenic bladder: A case report

RATIONALE

Patients with Down syndrome (DS) have a higher incidence of nonneurogenic neurogenic bladder (NNB) than do normal subjects. Renal failure may occur frequently in NNB patients. Although most of the cases of NNB patients with DS reported to date have been acute renal injuries, we report a patient with DS who was diagnosed late with urinary tract obstruction due to NNB that finally proceeded to end-stage renal disease (ESRD). This case of terminal renal failure is the first such reported case in the world.

PATIENT CONCERNS

A 35-year-old female patient had visited another hospital for 1 month for abdominal discomfort, nausea, constipation, and palpable mass. Cystic mass in the pelvic cavity, increased BUN, and Cr findings were observed. Residual urine was 1.8 L. She had a history of DS.

DIAGNOSES

Based on computed tomography and urodynamic study, ESRD due to NNB was diagnosed.

INTERVENTIONS

An emergency hemodialysis was performed and a catheter was inserted into the bladder. Transfusion and amlodipine were administered according to the patient's condition. There was no improvement in renal function seen, and so arteriovenous fistula surgery and regular hemodialysis were performed.

OUTCOMES

The patient was discharged from the hospital with a bladder catheter. She was visited on a regular basis for catheter replacement and hemodialysis.

LESSONS

Patients with DS have lower intelligence than normal people and often do not recognize or complain about inconveniences, even in the presence of urinary symptom. NNB has good prognosis when treated early, but there is a risk of ESRD if the diagnosis and treatment are delayed, as was the case here. Considering that the prevalence of NNB and other urinary tract diseases is high in patients with DS, clinicians need to take careful histories and observe deeply, even if the patient does not mention certain issues.

Smoking and its association with cryptorchidism in Down syndrome

INTRODUCTION

Cryptorchidism is a common and prevalent condition in patients with Down syndrome. Environmental factors, such as smoking, can be associated with malformations during fetal development. The study of the prevalence of cryptorchidism and its association with parental tobacco use in Down syndrome can contribute to alert health care professionals, patients and family members regarding the prevention of the harms caused by cryptorchidism and its possible predisposing factors.

OBJECTIVE

To evaluate the prevalence of cryptorchidism in Down syndrome and its association with maternal and paternal smoking.

METHOD

Forty (40) patients of a public clinic specialized in Down syndrome were evaluated, using a semi-structured questionnaire for evaluation of antecedents and sociodemographic characteristics, as well as physical and complementary examinations.

RESULTS

Cryptorchidism was observed in 27.5% of the patients (95CI 15.98-42.96). Of these, 55% (5/9) were the children of mothers who smoked during pregnancy, and 19.35% (6/31) were the children of mothers who did not smoke during pregnancy (OR = 5.26 [95CI 1.06-25.41]; p=0.032). Similarly, paternal smoking was also observed in greater frequency among the parents of cryptorchid patients compared with subjects with descended testis, 63.36% (7/11) and 31.03% (9/29), respectively (OR = 3.89 [95CI 0.91-16.73]; p=0.060).

CONCLUSION

The prevalence of cryptorchidism is high in patients with Down syndrome. We can show a strong association between smoking parents and the occurrence of cryptorchidism, especially when it comes to maternal smoking.

MiR-93-5p inhibits the EMT of breast cancer cells via targeting MKL-1 and STAT3

Epithelial-mesenchymal transition (EMT) plays an important role in breast cancer cell metastasis. Both (megakaryoblastic leukemia)/myocardin-like 1 (MKL-1) and Signal transducer and activator of transcription 3 (STAT3) have been implicated in the control of cellular metabolism, survival and growth. Our previous study has shown that cooperativity of MKL-1 and STAT3 promoted breast cancer cell migration. Herein, we demonstrate a requirement for MKL-1 and STAT3 in miRNA-mediated cellular EMT to affect breast cancer cell migration. Here we show that cooperativity of MKL-1 and STAT3 promoted the EMT of MCF-7 cells. Importantly, MKL-1 and STAT3 promoted the expression of Vimentin via its promoter CArG box. Interestingly, miR-93-5p inhibits the EMT of breast cancer cells through suppressing the expression of MKL-1 and STAT3 via targeted their 3'UTR. These results demonstrated a novel pathway through which miR-93-5p regulates MKL-1 and STAT3 to affect EMT controlling breast cancer cell migration.

Down syndrome-A narrative review with a focus on anatomical features

Down syndrome (DS) is the most common aneuploidy of chromosome 21, characterized by the presence of an extra copy of that chromosome (trisomy 21). Children with DS present with an abnormal phenotype, which is attributed to a loss of genetic balance or an excess dose of chromosome 21 genes. In recent years, advances in prenatal screening and diagnostic tests have aided in the early diagnosis and appropriate management of fetuses with DS. A myriad of clinical symptoms resulting from cognitive, physical, and physiological impairments caused by aberrations in various systems of the body occur in DS. However, despite these impairments, which range from trivial to fatal manifestations, the survival rate of individuals with DS has increased dramatically from less than 50% during the mid-1990s to 95% in the early 2000s, with a median life expectancy of 60 years reported recently. The aim of this narrative review is to review and summarize the etiopathology, prenatal screening and diagnostic tests, prognosis, clinical manifestations in various body systems, and comorbidities associated with DS. Clin. Anat. 29:568-577, 2016. © 2015 Wiley Periodicals, Inc.

Down Syndrome Increases the Risk of Short-Term Complications After Total Hip Arthroplasty

BACKGROUND

Down syndrome is the most common chromosomal abnormality and is associated with degenerative hip disease. Because of the recent increase in life expectancy for patients with this syndrome, orthopaedic surgeons are likely to see an increasing number of these patients who are candidates for total hip arthroplasty (THA).

METHODS

Using Nationwide Inpatient Sample (NIS) data from 1998 to 2010, we compared the short-term adverse outcomes of THA among 241 patients with Down syndrome and a matched 723-patient cohort. Specifically, we assessed: (1) incidence of THA; (2) perioperative medical and surgical complications during the primary hospitalization; (3) length of stay; and (4) hospital charges.

RESULTS

The annual mean number of patients with Down syndrome undergoing THA was 19. Compared to matched controls, Down syndrome patients had an increased risk of perioperative (OR, 4.33; P<.001), medical (OR, 4.59; P<.001) and surgical (OR, 3.51; P<.001) complications during the primary hospitalization. Down syndrome patients had significantly higher incidence rates of pneumonia (P=.001), urinary tract infection (P<.001), and wound hemorrhage (P=.027). The mean lengths of stay for Down syndrome patients were 26% longer (P<.001), but there were no differences in hospital charges (P=.599).

CONCLUSION

During the initial evaluation and pre-operative consultation for a patient with Down syndrome who is a candidate for THA, orthopaedic surgeons should educate the patient, family and their clinical decision makers about the increased risk of medical complications (pneumonia and urinary tract infections), surgical complications (wound hemorrhage), and lengths of stay compared to the general population.

Exploration of the treatment challenges in men with intellectual difficulties and testicular cancer as seen in Down syndrome: single centre experience

Down syndrome is the most common chromosomal disorder in humans as well as the most common cause of inherited intellectual disability. A spectrum of physical and functional disability is associated with the syndrome as well as a predisposition to developing particular malignancies, including testicular cancers. These tumours ordinarily have a high cure rate even in widely disseminated disease. However, individuals with Down syndrome may have learning difficulties, behavioural problems, and multiple systemic complications that have the potential to make standard treatment more risky and necessitates individualized approach in order to avoid unacceptable harm. There is also suggestion that tumours may have a different natural history. Further, people with learning disabilities have often experienced poorer healthcare than the general population. In order to address these inequalities, legislation, professional bodies, and charities provide guidance; however, ultimately, consideration of the person in the context of their own psychosocial issues, comorbidities, and possible treatment strategies is vital in delivering optimal care. We aim to present a review of our own experience of delivering individualized care to this group of patients in order to close the existing health inequality gap.

Prevalence of lower urinary tract symptoms in individuals with Down syndrome

OBJECTIVES

Down syndrome (DS), which is caused by the trisomy of chromosome 21, is the most frequent of all genetic syndromes. The current study aims to estimate the prevalence of lower urinary tract symptoms (LUTS) in individuals with DS buy using the Dysfunctional Voiding Symptom Score (DVSS) and correlate with functional constipation, age, and gender, as well as determine the most sensitive and specific factors associated with LUTS.

METHODS

LUTS was assessed in individuals with DS using a cross-sectional study through the application of a validated and adapted version of the DVSS for the Brazilian population. The presence of functional constipation was evaluated according to the Rome III criteria.

RESULTS

Of the 114 individuals assessed, 84 were included in the study (median age 16 ± 5.0 years, 66.7% female). The prevalence of LUTS was 27.3%. The symptoms were more frequent in males (OR 3.0, 95% CI 1.1-8.3, p = 0.03) and in individuals younger than 10 years of age (OR 5.2, 95% CI 1.8-14, p = 0.001). Functional constipation was observed in 50% of subjects. It was detected in 95.65% of the individuals with LUTS and 32.78% without LUTS (OR 45.1, 95% CI 5.66-301, p = 0.001). The symptom listed in question 8 ("push to pee") was the most specific indicator. When present, this symptom indicated a higher probability of LUTS (LR+ = 6.3), while the symptom listed in question 4 ("push for bowel movements to come out") showed high sensitivity and, when absent, indicated a lower probability of LUTS (LR- = 0.1).

CONCLUSIONS

LUTS was more prevalent in young males with DS and appeared to improve with age. Functional constipation was strongly associated with LUTS. These findings will contribute to raising the awareness of professionals involved in the follow-up of individuals with DS regarding the clinical manifestations and the need for a standardized investigation of LUTS.

Imaging findings in Down syndrome

Down syndrome, or trisomy 21, is the most common chromosomal anomaly and is characterized by intellectual disability and a typical facies. People with Down syndrome can have abnormalities of multiple organ systems. Cardiac and respiratory system involvement is the most common cause of morbidity and mortality, although every organ system can be affected. Patients may present prenatally with findings on screening sonography. If the diagnosis is not made prenatally, it is apparent at birth because of the characteristic facial features and musculoskeletal findings. Children with Down syndrome present to the radiology department at various ages depending on the severity of the specific finding. The purpose of this paper is to review the most common antenatal and postnatal imaging findings of Down syndrome as they manifest throughout the body.

Down syndrome with end-stage renal disease

Down syndrome is one of the most common genetic causes of learning disabilities in children. Although the incidence of renal and urological involvement in Down syndrome is not very common, monitoring of patients with Down syndrome for renal diseases should be done regularly as patient's age into the second and third decades. With increased survival, it appears that a growing number of these patients present with chronic renal failure. Down syndrome patients are apparently not suited for peritoneal dialysis because of lacking cooperation. This procedure can be prone to failure, mainly because of an increased risk of peritonitis. Handling such patients especially those on peritoneal dialysis is challenging. Here we report a case of Down syndrome with end-stage renal disease treated with hemodialysis for 6 months. To the best of our knowledge and current literature review this is the first case report of a patient with Down syndrome undergoing hemodialysis.

Biomarkers of age effect on renal function in Down syndrome

OBJECTIVE

To assess differences in kidney function between Down syndrome (DS) individuals and a control group related to aging.

METHODS

Creatinine (Cr) and specific gravity (SG) were assessed by spectrophotometric and refractometric assays in urine samples of 103 individuals with DS and 82 age-matched controls.

RESULTS

Significantly lower levels of Cr and SG were found in DS after puberty. Significant correlations were found between SG and age as well as between Cr and SG in DS and controls (p ≤ 0.05).

CONCLUSIONS

Premature aging in kidneys of DS patients could lead to an impaired renal function.

Acquired glomerular lesions in patients with Down syndrome

The long-term survival of persons with Down syndrome has dramatically increased over the past 50 years. There are no studies addressing the spectrum of glomerular lesions in these patients. We reviewed the clinical-pathologic characteristics of 17 patients with Down syndrome who underwent renal biopsy. The cohort consisted of 12 whites and 5 African Americans with mean age of 29 years (range, 6-45 years). History of hypothyroidism was present in 8 patients. Renal presentations included renal insufficiency (15 patients, mean serum creatinine 3.4 mg/dL), proteinuria (all patients, including 3 with nephrotic syndrome, mean 24-hour urine protein 4.2 g), and hematuria (14 patients, including 4 with gross hematuria). The glomerular diseases found on biopsy were IgA nephropathy (n = 5 patients), focal segmental glomerulosclerosis (n = 4), membranoproliferative glomerulonephritis (n = 2), acute postinfectious glomerulonephritis (n = 2), pauci-immune crescentic glomerulonephritis (n = 2), membranous glomerulonephritis (n = 1), and lupus nephritis (n = 1). Follow-up (mean, 47 months; range, 2-141 months) was available on 16 patients (94%). Two patients (1 with membranous glomerulonephritis and 1 with acute postinfectious glomerulonephritis) had complete remission; 8 patients (4 with IgA nephropathy, 2 with focal segmental glomerulosclerosis, 1 with lupus nephritis, and 1 with acute postinfectious glomerulonephritis) had chronic kidney disease; and 6 patients (2 with pauci-immune crescentic glomerulonephritis, 2 with membranoproliferative glomerulonephritis, 1 with IgA nephropathy, and 1 with focal segmental glomerulosclerosis) progressed to end-stage renal disease, 4 of whom died. In summary, a wide spectrum of glomerular diseases can be seen in patients with Down syndrome, with IgA nephropathy and focal segmental glomerulosclerosis being the most common. Renal biopsy is necessary to determine the type of glomerular lesion and appropriate treatment.

Increased prevalence of renal and urinary tract anomalies in children with Down syndrome

OBJECTIVE

The goal was to investigate the prevalence of renal and urinary tract anomalies (RUTAs) in a Down syndrome (DS) population.

METHODS

Data were obtained from the New York State Congenital Malformation Registry (NYS-CMR) in this retrospective cohort study. The occurrence of RUTAs was assessed for children with and without DS who were born in NYS between 1992 and 2004. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for each malformation.

RESULTS

Between 1992 and 2004, 3832 children with DS and 3 411 833 without DS were born in NYS. The prevalence of RUTAs in the DS population was 3.2%, compared with 0.7% in the NYS population (OR: 4.5 [95% CI: 3.8 -5.4]). Children with DS had significantly increased risks of anterior urethral obstruction (OR: 29.7 [95% CI: 4.0 -217.7]), cystic dysplastic kidney (OR: 4.5 [95% CI: 1.5-14.1]), hydronephrosis (OR: 8.7 [95% CI: 6.8 -11.0]), hydroureter (OR: 8.5 [95% CI: 3.5-20.4]), hypospadias (OR: 2.0 [95% CI: 1.4 -2.9]), posterior urethral valves (OR: 7.1 [95% CI: 1.8 -28.8]), prune belly syndrome (OR: 11.9 [95% CI: 1.6 - 85.4]), and renal agenesis (OR: 5.4 [95% CI: 2.8 -10.4]). There was no significantly increased risk of ectopic kidney (OR: 1.6 [95% CI: 0.2-11.2]) or ureteropelvic junction obstruction (OR: 1.4 [95% CI: 0.2-9.9]) in the DS population.

CONCLUSION

Children with DS have significantly increased risks of RUTAs.

Unnoticed post-void residual urine volume in people with moderate to severe intellectual disabilities: prevalence and risk factors

BACKGROUND

Increased post-void residual urine volume (PVR) is often seen in geriatric populations. People with intellectual disabilities (ID) have risk factors in common with these populations.

AIMS

To investigate in adults with ID: Feasibility of portable ultrasound bladder scanning; Prevalence of PVR; and Relations with proposed risk factors for PVR.

METHODS

In a cross-sectional design, PVR was measured using ultrasound scanning in 346 adults with moderate to severe ID aged 18-82 years. Relationship between increased PVR and the following risk factors was assessed: age, level of ID, gender, ambulancy, medication, chronic illnesses, incontinence and profound multiple disabilities (PMD). Acceptation of scanning and manageability were noted.

RESULTS

Feasibility: All participants were cooperatively undergoing the ultrasound scan and all outcomes were sufficiently interpretable. Prevalence: PVR >or= 150 mL was newly identified in 30/346 persons (8.7%, 95% confidence interval 5.92-12.14). Associations: Higher age (P = 0.001), laxative use (P = 0.001), chronic illnesses other than epilepsy (P = 0.005), profound ID (P = 0.008), incontinence (P = 0.048) and immobility(P = 0.005) are determinants that were associated with urinary retention.

CONCLUSIONS

The bladder ultrasound scan is a feasible method to identify increased PVR in adults with more severe levels of ID. The prevalence of PVR in adults is similar to prevalences found in the geriatric general population.

Undescended testis: current theories of etiology

PURPOSE OF REVIEW

Nonsyndromic cryptorchidism or undescended testis is a structural defect of infants and children whose etiology is unknown but likely related to a combination of genetic susceptibility and environmental factors. This review will focus on factors that may contribute to the etiology of this common and complex disease.

RECENT FINDINGS

The incidence of cryptorchidism is estimated to be 2-4% or higher in some populations. Data suggesting increasing prevalence are conflicting, possibly related to problems with diagnostic accuracy. Increased risk of cryptorchidism in first-degree relatives suggests a significant genetic contribution to susceptibility. Sequence variants within key candidate genes, such as insulin-like 3 and relaxin/insulin-like family peptide receptor 2, in cases of nonsyndromic cryptorchidism are infrequent and of unclear significance. Epidemiological data suggest that fetal growth restriction, maternal factors such as smoking, alcohol use and gestational diabetes, and exposure to environmental chemicals may contribute to risk, although data are inconsistent.

SUMMARY

The available evidence suggests a significant genetic contribution to cryptorchidism susceptibility that may be modulated by environmental risk factors. Additional studies are needed to define these factors, their complex interaction and their effects on testicular development and descent.

Down syndrome and the enteric nervous system

Down syndrome (DS) is the most common chromosomal abnormality occurring in humans. Up to 77% of DS children have associated gastrointestinal (GI) abnormalities, which may be structural or functional in nature. Functional disturbances may, in turn, affect the outcome of corrective surgical procedures, prompting to caution. It is becoming clear that the processes affecting the enteric nervous system (ENS) in DS not only affect the micro-anatomy but also nerve function, and there is some histological evidence of ENS variations in both human and DS animal models. This suggests that developmental disorders of the ENS are probably fundamental to the functional GI disturbances encountered in patients with DS. The anomalous brain development, function and resulting intellectual impairment associated with DS appears to result from the genetic imbalance created by the trisomy of chromosome 21. The possible links between the brain, GI and ENS involvement are not as yet entirely clear. Neurotropic factors affecting brain development during embryogenesis are probably interlinked with ENS development, but the precise mechanism of how this occurs has yet to be established. This study explores what is known about the ENS dysfunction in DS and reviews the possible importance of chromosome 21 located and other genes in its etiology. Functional motor disturbances of the esophagus and colon are not uncommon and may be congenital or acquired in nature. The most prominent of these include esophageal dysmotility syndromes (e.g. achalasia, gastroesophageal reflux, dysphagia) as well as a higher incidence of chronic constipation and Hirschsprung's disease (HSCR) (2-15%) occurring in association with DS. Chromosome 21 itself is thought to be the site of a modifier gene for HSCR. Recently identified candidate genetic mechanisms provide unique insights into the genetic background of the neurological and cognitive disorders associated with DS. Although the role of the triplicated chromosome 21 and genetic dosage remain important, the additional role of other chromosome 21 genes in the etiology of ENS developmental anomalies remains undetermined and requires ongoing research.

Testicular microlithiasis in patients with Down syndrome

OBJECTIVES

Testicular microlithiasis (TM) occurs with benign as well as with pathological conditions, such as testicular cancer. Since Down syndrome (DS) may be associated with increased frequency of testicular cancer, we determined the prevalence of TM in DS in patients from a DS clinic and evaluated the prevalence by age group.

STUDY DESIGN

We compared results of research scrotal ultrasounds obtained from 1998 to 2001 from 92 Latino patients with DS (ages newborn to 29.7 years) and clinical ultrasounds obtained from 1998 to 2004 from 200 Latino patients without DS (ages newborn to 18.3 years). We also reviewed the medical records.

RESULTS

The prevalence of TM in DS was 29%, significantly higher than the 7% found in patients without DS (P < .0001). Twenty of the 27 patients with DS and TM had no testicular pathology clinically or by history. The TM prevalence in the entire group of patients with and without DS increased with advancing age.

CONCLUSIONS

We found a significantly increased prevalence of TM in DS. The clinical significance of TM needs to be investigated further.

Renal involvement in Down syndrome

Kidney disease has not been considered a frequent complication in Down syndrome (DS) patients; a variety of urological abnormalities and glomerulopathies have been reported in this population, and some DS patients develop chronic renal failure (CRF). The aim of this study was to improve the understanding of renal disease in patients with DS, focusing on the incidence and range of kidney and urological abnormalities in a population of DS patients. A cross-sectional study was carried out in DS patients referred from a pediatric genetics unit of a tertiary care center. Medical records were reviewed. A 24-h urine specimen and a blood sample were obtained. Fractional excretion of sodium and potassium, tubular reabsorption of phosphate, urinary excretion of calcium, magnesium, uric acid, creatinine clearance and proteinuria were determined. Ultrasound was performed to evaluate the kidneys and the urinary tract. Laboratory data were reviewed for any possible renal disorder. Sixty-nine patients, aged 12 months to 24 years, were recruited. Pathological findings included three cases of voiding disturbances and a case of hypertension in a 7-year old girl. Eight patients (11.6%) had hyperuricemia without gout. Eighteen patients (24.2%) had hyperuricosuria. Urinalysis revealed three cases of mild proteinuria and two patients with microscopic hematuria. Minor radiological abnormalities were found in five patients (7.3%). Three patients (4.5%) had CRF. Renal disease in patients with DS is not as rare as previously thought, although the majority of findings are of minor relevance. According to the variety of pathologies, and in order to detect early irreversible renal injury, it seems quite reasonable to perform regular monitoring of renal function in these patients.