Genetic disease is a common cause of bilateral childhood cataract in Denmark

Long-term visual outcomes and ocular complications in children with Marner's hereditary cataracts operated in the period 1940-2021

PURPOSE

To investigate visual development and long-term complications after cataract surgery in childhood.

METHODS

This cross-sectional study included patients from a family with Marner's hereditary cataracts who had cataract surgery before 18 years of age. The study was conducted from 1 January 2022 until 31 December 2022. The patients contributed to their medical files and participated in an updated ophthalmologic examination.

RESULTS

We included 52 patients (101 eyes, 34 females). The median age at cataract surgery was 7 years (IQR: 5-10) and the age at examination was 40 years (IQR: 21-54). Primary and secondary intraocular lens implantation had been performed in 47.5% (25 patients, 48 eyes) and 16.8% (10 patients, 17 eyes). Visual acuity was ≤0.3 logMAR in 77% (78 eyes), and <0.5 logMAR in 8% (8 eyes). Glaucoma was present in 17% (9 patients, 12 eyes), ocular hypertension in 6% (3 patients, 4 eyes), and 10% (5 patients, 5 eyes) had prior retinal detachment. Mild visual field loss (2 < mean defect (MD) ≤ 6 dB) was found in 62% (63 eyes) and moderate to advanced visual field loss (MD > 6 dB) in 24% (24 eyes). Thirty-five patients (67%) held a driver's licence, and three were not allowed to drive due to low visual function. All patients were employed.

CONCLUSION

After cataract surgery in childhood, many patients achieve normal visual acuity, but mild visual field loss is common. Long-term follow-up is important due to the high risk of glaucoma.

Applying data science methodologies with artificial intelligence variant reinterpretation to map and estimate genetic disorder prevalence utilizing clinical data

Data science methodologies can be utilized to ascertain and analyze clinical genetic data that is often unstructured and rarely used outside of patient encounters. Genetic variants from all genetic testing resulting to a large pediatric healthcare system for a 5-year period were obtained and reinterpreted utilizing the previously validated Franklin© Artificial Intelligence (AI). Using PowerBI©, the data were further matched to patients in the electronic healthcare record to associate with demographic data to generate a variant data table and mapped by ZIP codes. Three thousand and sixty-five variants were identified and 98% were matched to patients with geographic data. Franklin© changed the interpretation for 24% of variants. One hundred and fifty-six clinically actionable variant reinterpretations were made. A total of 739 Mendelian genetic disorders were identified with disorder prevalence estimation. Mapping of variants demonstrated hot-spots for pathogenic genetic variation such as PEX6-associated Zellweger Spectrum Disorder. Seven patients were identified with Bardet-Biedl syndrome and seven patients with Rett syndrome amenable to newly FDA-approved therapeutics. Utilizing readily available software we developed a database and Exploratory Data Analysis (EDA) methodology enabling us to systematically reinterpret variants, estimate variant prevalence, identify conditions amenable to new treatments, and localize geographies enriched for pathogenic variants.

Identification of pathogenic genetic variants in patients with acquired early-onset bilateral cataracts using next-generation sequencing

BACKGROUND

Acquired early-onset bilateral cataracts can result from systemic etiologies or genetic disorders.

METHODS

In this observational study, we analyzed individuals 18 months to 35 years of age with acquired bilateral cataracts via a next-generation sequencing panel of 66 genes to identify disease-causing genetic variants.

RESULTS

Of 347 patients enrolled, 313 (90.2%) were <19 years (median, 8 years). We identified 74 pathogenic or likely pathogenic variants in 69 patients. Of the variants, we observed 64 single nucleotide variants (SNV) in 24 genes and 10 copy number variants (CNV) of varying size and genomic location. SNVs in crystallin genes were most common, accounting for 27.0% of all variants (20 of 74). Of those, recurrent variants included known cataract-causing variants CRYBA1 c.215+1G>A, observed in 3 patients, and CRYBA1 c.272_274delGAG, CRYBB2 c.463C>T and c.562C>T, and CRYAA c.62G>A, each observed in 2 patients. In 5 patients, we identified CNV deletions ranging from 1.32-2.41 Mb in size associated with 1q21.1 microdeletion syndrome. Biallelic variants in CYP27A1 were identified in two siblings, one as part of targeted follow-up family testing, who were subsequently diagnosed with cerebrotendinous xanthomatosis, a rare but treatable autosomal recessive disease that often presents with acquired early-onset bilateral cataracts.

CONCLUSIONS

This study demonstrates the utility of genetic testing in individuals with acquired early-onset bilateral cataracts to help clarify etiology. Identification of causative genetic variants can inform patient management and facilitate genetic counseling by identifying genetic conditions with risk of recurrence in families.

Long-term risk of glaucoma after cataract surgery in childhood

PURPOSE

To examine the long-term risk of glaucoma after cataract surgery in childhood.

METHODS

This study took place from January 2022 until December 2022 and included patients from a large family with hereditary childhood cataract who had cataract surgery before 18 years of age. Patients underwent an ophthalmologic examination to determine the presence of glaucoma or ocular hypertension (OHT). Patients who did not want to participate in the examination could contribute with a medical journal from their treating ophthalmologist. The risk of long-term glaucoma was determined using survival analysis, and risk factors were assessed using a Cox proportional hazards regression model.

RESULTS

We included 68 patients (133 eyes) with a median age at cataract surgery of 7 years (IQR: 5-10). The median follow-up time after cataract surgery to glaucoma/OHT or the latest ophthalmologic examination was 35 years (IQR: 15-48). Twelve patients (18 eyes) had glaucoma, and five patients (eight eyes) had OHT, resulting in 15 patients with glaucoma/OHT. The long-term risk of glaucoma/OHT diagnosed in adulthood was 47.7% (CI: 21.8-70.9) at the age of 70 years of patients who were free of glaucoma before their 18th year. We could not confirm or dismiss an association between glaucoma/OHT and sex, age at surgery, number of ocular interventions before 18 years of age or glaucoma after cataract surgery in a first-degree relative.

CONCLUSION

Cataract surgery in childhood is associated with a high risk of late-onset glaucoma. Regular lifelong follow-up is important to ensure early diagnosis and prevent extensive vision loss.

Novel CRYGC Mutation in Conserved Ultraviolet-Protective Tryptophan (p.Trp131Arg) Is Linked to Autosomal Dominant Congenital Cataract

Congenital cataract (CC), the most prevalent cause of childhood blindness and amblyopia, necessitates prompt and precise genetic diagnosis. The objective of this study is to identify the underlying genetic cause in a Swiss patient with isolated CC. Whole exome sequencing (WES) and copy number variation (CNV) analysis were conducted for variant identification in a patient born with a total binocular CC without a family history of CC. Sanger Sequencing was used to confirm the variant and segregation analysis was used to screen the non-affected parents. The first de novo missense mutation at c.391T>C was identified in exon 3 of CRYGC on chromosome 2 causing the substitution of a highly conserved Tryptophan to an Arginine located at p.Trp131Arg. Previous studies exhibit significant changes in the tertiary structure of the crystallin family in the following variant locus, making CRYGC prone to aggregation aggravated by photodamage resulting in cataract. The variant can be classified as pathogenic according to the American College of Medical Genetics and Genomics (ACMG) criteria (PP3 + PM1 + PM2 + PS2; scoring 10 points). The identification of this novel variant expands the existing knowledge on the range of variants found in the CRYGC gene and contributes to a better comprehension of cataract heterogeneity.

Diagnostic yield of workups ordered by pediatric ophthalmologists for bilateral pediatric cataracts at a tertiary pediatric hospital in the United States

BACKGROUND

Children with unexplained bilateral cataracts routinely undergo testing for genetic, infectious, and metabolic etiologies. We evaluated the diagnostic yield of various tests ordered by pediatric ophthalmologists to evaluate bilateral cataracts in children at a single institution.

METHODS

We retrospectively identified all children with bilateral unexplained cataracts who underwent cataract surgery by a pediatric ophthalmologist at Children's Hospital Colorado from 2006 to 2022. We reviewed the results of genetic, infectious, and metabolic testing ordered by pediatric ophthalmologists to evaluate the cataracts in these children.

RESULTS

A total of 43 children met inclusion criteria. Of these, 34 (79%) had genetic testing, 34 (79%) had infectious disease testing, 33 (77%) had galactosemia testing, and 17 (40%) had urine-reducing substances testing performed during their cataract evaluation. Of the genetic tests ordered, 17 (50%) revealed a pathogenic mutation associated with cataracts. Twenty-three (68%) patients were IgG-positive for a TORCH infection, but no child was found to be positive on confirmatory testing. Of the galactosemia and URS tests ordered, 3 tests (9%) and 1 (6%) test were initially found to be abnormal, respectively, but confirmatory testing and clinical judgment ruled out metabolic disease in each case.

CONCLUSIONS

Genetic testing should be strongly considered in all cases of unexplained bilateral pediatric cataracts. Metabolic and infectious testing is best considered only after consultation with the child's pediatrician, guided by the patient's clinical context and the availability of genetic testing.

School performances in children with cataract: results from a population-based cohort study

OBJECTIVES

Childhood cataract is a chronic condition that may interfere with the child's learning capacities. We aimed to investigate whether childhood cataract influences academic development by comparing school performance in reading and mathematics in children with cataract to a matched control group.

DESIGN

Nationwide registry-based cohort study.

SETTINGS

Two surgical centres that perform all treatments for childhood cataract in Denmark.

PARTICIPANTS

Children born between 2000 and 2009 diagnosed with cataract before 10 years of age (n=275) and an age-matched and sex-matched control group (n=2473).

MAIN OUTCOME MEASURES

School performance was assessed as test scores in national tests performed at regular intervals from grade 2 to grade 8 in reading and mathematics. Analyses were corrected for birth origin, child somatic and mental disorder and parental socioeconomic status and mental disorders.

RESULTS

Of 275 children, 85 (30.9%) were operated for bilateral cataract, 79 (28.7%) unilateral cataract and 111 (40,4%) were not operated. We found that children with cataract have lower participation rate in the tests (62.5%) compared with the control cohort (77.2%) (p value=0.0001). After adjusting the pooled analyses for birth origin, somatic and mental disease in the child and parental socioeconomic status and mental disorders, we found that the children with cataract scored significantly lower in mathematics compared with those without cataract (mean difference=-4.78, 95% CI: -8.18 to -1.38, p value=0.006), whereas no difference was found regarding scores in reading (p=0.576). The lower score in mathematics was driven by children who had been operated for bilateral cataract (p-value=0.004).

CONCLUSION

Children with cataract without somatic or neurodevelopmental comorbidities or psychosocial adversities seem to do well in school, whereas children operated for bilateral cataract have higher frequencies of difficulties in mathematical tasks.