Heart defects and ocular anomalies in children with Down's syndrome

Systemic and Ophthalmic Manifestations in Different Types of Refractive Errors in Patients with Down Syndrome

Background and Objective: This study aims to investigate the prevalence of systemic and ophthalmic manifestations in different refractive groups in children and young adults with Down syndrome (DS). Materials and Methods: The study was a population-based, cross-sectional study that included 141 Caucasian children and young adults with DS. They were classified into the following three groups: myopia DS group (37 subjects, mean age 15.8 years), emmetropia DS group (41 subjects, mean age 11.7 years) and hyperopia DS group (63 subjects, mean age 10.9 years). The participants underwent inspection, slit-lamp examination, cycloplegic refraction, ocular alignment and ocular motility examination. Ten systemic manifestations were analyzed. Results: There was no difference in the prevalence of any systemic manifestations between the groups. Considering the ophthalmic manifestations, there was statistical difference in the distribution of proportions among the three groups for nystagmus (p = 0.011), iris-stromal atrophy (p = 0.048) and strabismus (p = 0.031). The prevalence of strabismus in our DS myopia group was 35.1%, and in DS hyperopia group 38.1%. Conclusions: The results of our study suggest that DS children and young adults with any refractive error do not have a higher chance of additional systemic manifestations. Myopia in DS was associated with a higher prevalence of nystagmus and iris stromal atrophy, whereas astigmatism was found to be more frequent in hyperopia.

Visual and Refractive Status of Children With Down's Syndrome and Nystagmus

Purpose

Children with Down's syndrome (DS) are known to have poorer visual acuity than neurotypical children. One report has shown that children with DS and nystagmus also have poor acuity when compared to typical children with nystagmus. What has not been established is the extent of any acuity deficit due to nystagmus and whether nystagmus affects refractive error within a population with DS.

Methods

Clinical records from the Cardiff University Down's Syndrome Vision Research Unit were examined retrospectively. Binocular visual acuity and refraction data were available for 50 children who had DS and nystagmus and 176 children who had DS but no nystagmus. Data were compared between the two groups and with published data for neurotypical children with nystagmus.

Results

The study confirms the deficit in acuity in DS, compared to neurotypical children, of approximately 0.2 logMAR and shows a deficit attributable to nystagmus of a further 0.2 logMAR beyond the first year of life. Children with both DS and nystagmus clearly have a significant additional impairment. Children with DS have a wide range of refractive errors, but nystagmus increases the likelihood of myopia. Prevalence and axis direction of astigmatism, on the other hand, appear unaffected by nystagmus.

Conclusions

Nystagmus confers an additional visual impairment on children with DS and must be recognized as such by families and educators. Children with both DS and nystagmus clearly need targeted support.

Development of Nystagmus With the Absence of MYOD Expression in the Extraocular Muscles

Purpose

Myoblast determination protein 1 (MYOD) is a critical myogenic regulatory factor in muscle development, differentiation, myofiber repair, and regeneration. As the extraocular muscles significantly remodel their myofibers throughout life compared with limb skeletal muscles, we hypothesized that the absence of MYOD would result in their abnormal structure and function. To assess structural and functional changes in the extraocular muscles in MyoD-/- mice, fiber size and number and optokinetic nystagmus reflex (OKN) responses were examined.

Methods

OKN was measured in MyoD-/- mice and littermate wild-type controls at 3, 6, and 12 months. The extraocular muscles were examined histologically for changes in mean myofiber cross-sectional area, total myofiber number, and nuclei immunostained for PAX7 and PITX2, markers of myogenic precursor cells.

Results

The MyoD-/- mice developed nystagmus, with both jerk and pendular waveforms, in the absence and in the presence of moving visual stimulation. At 12 months, there were significant losses in mean myofiber cross-sectional area and in total number of orbital layer fibers in all rectus muscles, as well as in global layer fibers in the superior and inferior rectus muscles. Haploinsufficient mice showed abnormal OKN responses. PITX2-positive cell entry into myofibers of the MyoD-/- mice was significantly reduced.

Conclusions

This study is the first demonstration of the development of nystagmus in the constitutive absence of expression of the muscle-specific transcription factor MYOD. We hypothesize that myofiber loss over time may alter anterograde and/or retrograde communication between the motor nerves and extraocular muscles that are critical for maintaining normalcy of extraocular muscle function.

Clinical and genetic findings in patients with congenital cataract and heart diseases

Background

Congenital cataract (CC) and congenital heart disease (CHD) are significant birth defects. In clinical practice, the concurrence of CC and CHD is frequently observed in patients. Additionally, some monogenic diseases, copy number variation (CNV) syndromes, and diseases associated with intrauterine infection involve both cataract and heart defects. However, little is known about the association between CC and CHD. Here, we characterised the demographic, clinical, and genetic features of patients with CC and heart defects.

Methods

Medical records for 334 hospitalised patients diagnosed with CC were reviewed. Demographic and clinical features of patients with CC with and without CHD were compared. Clinical and genomic information for patients with ‘cataract’ and ‘cardiac defects’ were reviewed from Database of Chromosomal Imbalance and Phenotype in Humans using Ensembl Resources (DECIPHER). Microarray-based comparative genomic hybridisation and whole-exome sequencing were performed in 10 trio families with CC and CHD to detect de novo genomic alterations, including copy number variants and single nucleotide changes.

Results

In a retrospective analysis of 334 patients with CC over the past 10 years at our hospital, we observed a high proportion of patients (41.13%) with CHD (including innocent CHD, which reported as left-to-right shunt in echocardiography test). The CC with CHD group had higher incidences of preterm birth and Down’s syndrome than the CC without CHD group. Atrial septal defect was the most frequent heart defect. A total of 44 cases with cataracts and heart diseases were retrieved from Database of Chromosomal Imbalance and Phenotype in Humans using Ensembl Resources (DECIPHER). In total, 52 genomic alterations were reported, 44% of which were de novo germline variants. In the 10 trio families with CC and CHD, we found de novo CNVs responsible for two well-known chromosomal disorders and identified a novel pathogenic mutation in GJA8 responsible for CC.

Conclusions

We observed significant associations between CHD and CC in our 10-year patient cohort. Based on the cohort and data from DECIPHER, developmental syndromes in some patients were due to genetic defects, thus explaining the concurrence of CC and CHD. Additionally, we detected de novo mutations as an independent cause of cataracts. Our findings suggest that developmental syndromes in patients with CC deserve more attention in clinical practice by ophthalmologists.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01873-7.

Chromosome-wise Protein Interaction Patterns and Their Impact on Functional Implications of Large-Scale Genomic Aberrations

Gene copy-number changes influence phenotypes through gene-dosage alteration and subsequent changes of protein complex stoichiometry. Human trisomies where gene copy numbers are increased uniformly over entire chromosomes provide generic cases for studying these relationships. In most trisomies, gene and protein level alterations have fatal consequences. We used genome-wide protein-protein interaction data to identify chromosome-specific patterns of protein interactions. We found that some chromosomes encode proteins that interact infrequently with each other, chromosome 21 in particular. We combined the protein interaction data with transcriptome data from human brain tissue to investigate how this pattern of global interactions may affect cellular function. We identified highly connected proteins that also had coordinated gene expression. These proteins were associated with important neurological functions affecting the characteristic phenotypes for Down syndrome and have previously been validated in mouse knockout experiments. Our approach is general and applicable to other gene-dosage changes, such as arm-level amplifications in cancer.

Visual characteristics of children with Down syndrome

PURPOSE

To analyze long-term visual development in children with Down syndrome who received early ophthalmological intervention.

METHODS

A total of 125 children with Down syndrome who were examined before 6 years of age and followed up for more than 5 years were selected. Visual development, refraction, visual acuity testing, and the prescription of spectacles were examined retrospectively.

RESULTS

Mean visual acuity by age was as follows: 2 years, 1.13 ± 0.23 logarithm of the minimum angle of resolution (logMAR); 5 years, 0.55 ± 0.25 logMAR; 8 years, 0.27 ± 0.19 logMAR; 11 years, 0.17 ± 0.16 logMAR; and 14 years, 0.10 ± 0.15 logMAR. In 32 children (25.6%), visual acuity reached 0.0 logMAR or better. Hyperopia of +2D or more was observed in 132 eyes (52.8%), and astigmatism of 2D or more was observed in 153 eyes (61.2%). Subjective testing was difficult in many children prior to 4.5 years of age, and grating acuity testing was necessary. Spectacles were prescribed at a mean age of 3.5 ± 1.6 years in 120 children (96.0%). The average duration until the spectacles were worn constantly was 9.0 ± 9.3 months.

CONCLUSION

Early ophthalmological intervention and longitudinal care is important for children with Down syndrome.

Ophthalmic manifestations in children and young adults with Down syndrome and congenital heart defects

PURPOSE

To investigate whether different types of ocular manifestations are associated with congenital heart disease (CHD) in a large Caucasian population of children and young adults with Down syndrome (DS).

METHODS

Population-based, case-control study which included 185 subjects with DS (mean age 13.2 ± 7.9 years), who reported presence or absence of CHD; DS with CHD group (51 subjects, mean age 10.6 ± 5.6 years) and DS without CHD (134 subjects, mean age 14.2 ± 8.4 years).

RESULTS

In our sample with DS and CHD, strabismus was found in 15 subjects (29.4%), nystagmus in 1 (2.0%), epiblepharon in 21 (41.2%) and Brushfield spots in 15 (31.3%). In the DS without CHD group, strabismus was found in 38 participants (28.4%), nystagmus in 13 (9.7%), epiblepharon in 31 (23.5%) and Brushfield spots in 21 (16.0%). Only the variables epiblepharon and presence of Brushfield spots differed significantly between the two groups (p = 0.02 and p = 0.03, respectively). Hyperopia was present in 26 participants (53.1%) in the DS with CHD group, and in 65 (57.0%) in the DS without CHD group. Oblique astigmatism was present in 25 (52.1%) in the DS with CHD group and in 61 (53.5%) in the DS without CHD group.

CONCLUSIONS

Frequencies of DS participants presenting with strabismus, nystagmus, hyperopia and oblique astigmatism were not statistically different between those with CHD and those without CHD in this sample. Further studies are needed to confirm if there are associations between the presence of Brushfield spots or epiblepharon and CHD in patients with DS.

Strabismus surgery for children with developmental delay

PURPOSE OF REVIEW

To describe recent evidence regarding the surgical approach of strabismus in children with various forms of developmental delay.

RECENT FINDINGS

There remains variability in surgical outcomes with or without dose adjustment in strabismus surgery for children with developmental delay. However, this should not deter one from performing surgery - even early surgery, as fusional potential remains possible, which can especially impact the quality of vision and quality of life in developmentally delayed children.Future prospective, comparative, long-term studies with larger sample sizes for strabismus surgery in children with developmental delay are still needed.

SUMMARY

Strabismus is one of the most common ophthalmologic findings in children with developmental delay. Surgical correction of strabismus in children with developmental delay is well tolerated and effective, although it remains slightly less predictable, which can depend on the specific type of delay or underlying neurological deficit. Careful consideration of types and severity of developmental delay and attempts to measure binocular potential can help guide the timing, dosage, and type of treatment.Reoperations tend to be more frequently encountered in this population, and this higher degree of variability should be addressed in the consent process.Considering adjusting the surgical dosage in this population, taking careful preoperative measurements, and checking for fusional potential should be taken into account when managing children with developmental delay.

Visual acuity deficits in children with nystagmus and Down syndrome

PURPOSE

To investigate the association between visual acuity deficits and fixation instability in children with Down syndrome and nystagmus.

DESIGN

Prospective cross-sectional study.

METHODS

setting: Institutional. study population:Sixteen children (aged 10 months-14 years) with Down syndrome and nystagmus, and a control group of 93 age-similar children with unassociated infantile nystagmus. observation procedures: Binocular Teller acuity card testing and eye-movement recordings. Fixation stability was quantified using the nystagmus optimal fixation function (NOFF). An exponential model based on results from the control group with unassociated infantile nystagmus was used to relate fixation stability to age-corrected visual acuity deficits. main outcome measures: Binocular grating visual acuity and NOFF.

RESULTS

Visual acuity was 0.2-0.9 logMAR (20/30-20/174 Snellen equivalent) and corresponded to a 0.4 logMAR (4 lines) mean age-corrected visual acuity deficit. Fixation stability ranged from poor to mildly affected. Although visual acuity deficit was on average 0.17 logMAR larger (P = .005) than predicted by the model, most children had visual acuity deficit within the 95% predictive interval.

CONCLUSIONS

There was a small mean difference between the measured visual acuity deficit and the prediction of the nystagmus model. Although other factors also contribute to visual acuity loss in Down syndrome, nystagmus alone could account for most of the visual acuity deficit in these children.

Ocular abnormalities and systemic disease in Down syndrome

INTRODUCTION

Ocular problems as refractive errors, strabismus, accommodation, and cataract are well known in children with Down syndrome (DS). However, there is little information on the possible correlation of eye problems with systemic diseases such as heart defect (with or without surgery), hypotony, hypothyroidism, hearing loss, and others.

METHODS

Ophthalmic problems versus certain systemic diseases were studied in 65 children with DS, aged 2 months to 13 years, referred to the University Eye Hospital Ljubljana, Slovenia from 2008 to 2010. Standard ophthalmic examination methods were used, and physical data were taken from pediatric records.

RESULTS

Ocular findings included nystagmus (29.2%), esotropia (26.1%), epiphora (21.5%), Brushfield spots (16.9%), lens opacities (12.3%), abnormalities of the retinal vessels, foveal hypoplasia, or retinal pigment epithelium hyperplasia (32.2%), and optic disc pallor (7.6%). Hyperopia (36.9%) was the most frequent refractive error in the group, followed by astigmatism (29.2%) and myopia (24.6%). No diagnosed systemic abnormalities were found in 18.3% of the children, while 30.7% had congenital heart defect. Hypothyroidism, hypotony, hearing loss, gastrointestinal tract malformations, and leukemia were less common. Nystagmus was related to myopia and esotropia, and to heart disease and heart operations.

CONCLUSIONS

Comorbidities are common in DS and complicate diagnosis, development, and therapy.

[Frequency and clinical presentation of congenital ocular anomalies in Asturias 1990-2004]

INTRODUCTION

Congenital ocular anomalies (COAs) can produce serious disability.

OBJECTIVE

The purpose of this investigation was to assess the prevalence of COAs, their trends and to describe the associated malformations and syndromes in a geographically defined population.

METHOD

Data from the Asturias Registry of Congenital Defects were used. The period studied was from 1990 to 2004 and the study population the 103,452 births of mothers living in the region. Total prevalence was calculated.

RESULTS

A total of 3035 cases with congenital defects were recorded, of these 70 had COAs. The total prevalence was 6.8 per 10000 births, with a stable trend during this period. The most common COAs were: congenital cataract (2.0 per 10000 births), anophthalmos/microphthalmos (1.4 per 10000 births) and coloboma (1.3 per 10000 births). 40% of COAs occurred as isolated defects, 37% were syndromes and 23% were associated with other congenital defects.

CONCLUSIONS

The prevalence of COAs in Asturias over this period had a stable trend and the congenital cataract was the commonest COAs. COAs, particularly the anophthalmos/microphthalmos were associated with other congenital anomalies.

Morphology of dentition in Polish children with trisomy 21 (Down syndrome)

This paper compares the dimensions and non-metric dental traits between Down syndrome patients (DS) and a control group. A total of 1,210 teeth of subjects with Down syndrome (diagnosed as regular trisomy 21 type) were analyzed. The mesiodistal (MD) and labiolingual or buccolingual (BL) diameters of each dental crown were measured, and the selected non-metric dental traits evaluated. The teeth of male and female DS patients were found to have lower values of both measurements compared to controls (excepting for the mesiodistal diameter of the lower mandibular premolar both in males and females). Sexual dimorphism of dental crown dimensions characteristic of contemporary human populations (the highest M-F difference was lower than 6%) was also observed: boys' teeth, particularly canines, are bigger than girls' (2.33 on average). Disorders in maxillary tooth alignment and the faint shoveling of upper central incisors (grade 1 according to ASU scale) were noted significantly more often among Down syndrome patients, but descriptive features correlating with dental crown size were observed more rarely (e.g., the distal accessory ridge on the upper canine and tuberculum Carabelli on the first molar).

Ophthalmic abnormalities in children with Down syndrome

A comprehensive review of the available literature was performed to determine the common ophthalmic disorders in children aged 0 to 16 years with Down syndrome. The UK National Library for Health interface was used to search seven electronic databases, including MEDLINE and EMBASE. Terms related to Down syndrome, ophthalmology, and pediatrics were combined in the search strategy, which yielded 230 articles. Application of exclusion criteria left 23 articles to include in the review. Literature synthesis demonstrated that children with Down syndrome are at risk for several ocular disorders. Refractive error was a common finding, particularly hyperopia. Strabismus was also reported regularly, particularly esodeviation. Other frequent findings included poor visual acuity, nystagmus, and blepharitis, whereas cataract and glaucoma were less common but had potentially serious implications for future vision. Only one study compared routine pediatric examination to that of a pediatric ophthalmologist. The findings of this review confirm the need for an ophthalmic screening program for children with Down syndrome. Additional work should investigate how such a program could be best implemented and ascertain how to involve different professionals in such a service.

Refractive errors and ocular findings in children with intellectual disability: a controlled study

PURPOSE

To evaluate the ocular findings and refractive errors in children with intellectual disability and in controls of average intellectual development of similar socioeconomic backgrounds.

METHODS

The study was conducted at Diskapi Children's Hospital in Ankara, Turkey: 724 subjects with intellectual disability and 151 control subjects were evaluated. The subjects with intellectual disability were subdivided into mild (IQ 50-69, n = 490), moderate (IQ 35-49, n = 164), and severe (IQ <34, n = 70) groups, and syndromic (n = 138) versus nonsyndromic (n = 586) disability. All children underwent cycloplegic autorefraction or retinoscopy, slit-lamp biomicroscopy, and dilated fundus examination. Ocular alignment was assessed by Hirschberg, Krimsky, or prism cover test. The main outcome measure was the prevalence of refractive errors and ocular findings.

RESULTS

Seventy-seven percent of subjects with intellectual disability, and 42.4% of controls, had ocular findings. The children with intellectual disability had significantly more nystagmus, strabismus, astigmatism, and hypermetropia than controls. Children with syndromic intellectual disability had significantly more nystagmus, strabismus, astigmatism, and hypermetropia than subjects with nonsyndromic intellectual disability. Increasing severity of intellectual disability was related to higher prevalence of nystagmus, strabismus, astigmatism, hypermetropia, and anisometropia.

CONCLUSIONS

From a public health perspective, evaluation and treatment of ocular and refractive findings in children with moderate, severe, and syndromic intellectual disability categories is urgently needed and likely to be highly effective in alleviating future health and social care costs, as well as improving the productive lives of individuals with intellectual disability.

Skeletal age of individuals with Down syndrome

The aim of this study was to assess the skeletal age of Brazilian individuals with Down syndrome (DS) using the method of Greulich and Pyle. Forty subjects with DS between the ages of 6 and 16 years were studied and compared to a control sample of children without DS. The statistical analysis showed that at the age of 7 years the skeletal age (SA) of the individuals with DS was delayed in relation to their chronological age (CA) (SA < CA). On the other hand, at the age of 15 years, their SA was advanced in relation to their CA (SA > CA). An evaluation of the results suggests that the period of adolescent development for individuals with DS was shorter. These individuals reach the completion of bone maturation earlier compared to individuals without DS.

Association between accommodative accuracy, hypermetropia, and strabismus in children with Down's syndrome

PURPOSE

A significant proportion of children with Down's syndrome have been shown to have reduced accommodation. The purpose of this study was to investigate any association between reduced accommodation and refractive error, strabismus, visual acuity, and other ocular parameters.

METHODS

Subjects were children with Down's syndrome enrolled in a longitudinal cohort to monitor visual development. Twenty-seven children with accurate accommodation were age-matched to children with reduced accommodation based on their most recent assessment for which a full, reliable data set was available. Each child was used only once for matching. Cross-sectional ocular and visual data were analyzed using chi or Fisher's exact test, or the Mann-Whitney U test for (non-normally distributed) quantitative data.

RESULTS

Children with under-accommodation were statistically more likely to have moderate/high hypermetropia (> or = +3.00 D) and to be strabismic (most with esotropia). No significant difference between the groups was found for any other ocular parameters.

CONCLUSIONS

This study demonstrates the marked association between under-accommodation, hypermetropia, and strabismus in children with Down's syndrome. No causal relation can be demonstrated with these data, but findings suggest that the link between under-accommodation and hypermetropia (and between accurate accommodation and emmetropia) is present in early infancy.

Refractive errors in normal children and children with down syndrome or cerebral palsy

BACKGROUND AND PURPOSE

The prevalence of refractive errors in the general population is between 12 to 18%. The objective of the present study was to determine the refractive errors in healthy children and compare these results in patients with Down syndrome and with cerebral palsy.

MATERIAL AND METHOD

The refractive errors in patients between 6 to 12 years without ophthalmologic conditions were studied. The patients were divided into three groups: normal children, children with Down syndrome, and children with cerebral palsy. The results were compared.

RESULTS

258 patient were included: 200 normal children, 29 with Down syndrome, and 29 with cerebral palsy. Ametropia was found in 79.5% in the group of normal children, 93.2% in children with Down syndrome, and in 100% in children with cerebral palsy. Patients requiring optical correction included 30% in normal children, 48.2% in patients with Down syndrome, and 41.1% in the cerebral palsy group. Hyperopia was the most frequent refractive error in all three groups. Most of the refractive errors were mild to moderate.

CONCLUSIONS

Refractive errors are more frequent in patients with Down syndrome and cerebral palsy compared with normal children.