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Biomedical subjects

Brian G Ballios

Publications and source records attributed to Brian G Ballios.

2 recordsLinked to original sources
PubMed2026

Molecular diagnostic yield and barriers in inherited retinal diseases: a retrospective cohort study.

OBJECTIVE: To evaluate the diagnostic yield of panel-based genetic testing for inherited retinal diseases (IRDs) and identify barriers to molecular resolution. DESIGN: Retrospective cohort. PARTICIPANTS: A total of 404 patients with clinically confirmed IRDs who were evaluated at the Adult Inherited Retinal Dystrophy Service, Ontario, Canada (October 2021-September 2024). METHODS: Patients underwent targeted massive parallel sequencing panel testing. Diagnostic yield was calculated, and unresolved cases were reviewed. Associations between yield, phenotype, ethnicity, and sex were assessed using χ² analysis. RESULTS: Of 685 referrals, 570 had confirmed IRDs. After we excluded 140 pending results and 26 patients who declined testing, 404 patients were analyzed. At referral, 94 patients (23.2%) had a previous molecular diagnosis, and 138 (34.0%) were diagnosed through clinic-initiated testing, giving an overall yield of 57.4%. Yield varied significantly by phenotype (χ², P = 1.4 × 10⁻⁶), from 94.4% in vitelliform macular dystrophies to 25.0% in vitreoretinopathies, with no sex association (P = 1.0). Disease-causing variants were identified in 83 IRD-associated genes, most frequently ABCA4, USH2A, and BEST1. Of 172 unresolved cases, 62 (36.0%) had negative panels, and 110 (63.9%) were inconclusive, including 30 with unphased pathogenic variants in recessive genes and 10 with high-suspicion variants of uncertain significance. Key barriers included limited family availability for phasing, restricted access to functional assays, and lack of public coverage for whole-exome or whole-genome sequencing. CONCLUSIONS: Massive parallel sequencing-based panel testing achieved a 57% diagnostic yield in this IRD population. Success was strongly phenotype-dependent with substantial heterogeneity. Whole-exome sequencing, whole-genome sequencing, family segregation, and functional genomics could improve diagnostic outcomes and management.

Humans↗
PubMed2026

Association of hydroxyurea use and sickle cell retinopathy: A systematic review and meta-analysis.

Hydroxyurea (HU) is prescribed to reduce systemic complications of sickle cell disease; however, its association with sickle cell retinopathy (SCR) remains unclear. This meta-analysis (PROSPERO: CRD420251079006) evaluates the pooled association between HU use and SCR. In the primary analysis, HU use was not associated with a statistically significant reduction in SCR (OR = 0.90, 95% CI [0.41, 1.97], p = 0.79; I² = 77%). In a prespecified leave-one-out analysis, exclusion of the outlier study did not produce a statistically significant association, although the estimate shifted toward a stronger protective effect with reduced heterogeneity (OR = 0.70, 95% CI [0.39, 1.27], p = 0.25; I² = 67%). In a subgroup analysis excluding high-risk-of-bias studies, HU use was also not associated with a statistically significant reduction in SCR (OR = 0.84, 95% CI [0.39, 1.82], p = 0.66; I² = 77%). In post hoc analyses, HU use was not associated with a statistically significant reduction in SCR in non-adult populations (OR = 1.14, 95% CI [0.43, 3.05], p = 0.79; I² = 81%) or genotype-restricted analyses (OR = 1.22, 95% CI [0.81, 1.84], p = 0.35; I² = 0%). In post hoc analyses restricting studies to retinopathy phenotype, however, HU was associated with statistically significant lower odds of non-proliferative SCR (OR = 0.73, 95% CI [0.54, 0.98], p = 0.04; I² = 0%) and proliferative SCR (OR = 0.24, 95% CI [0.09, 0.60], p = 0.002; I² = 12%). Very low-certainty evidence suggests mixed associations between HU and SCR. Prospective studies are needed to clarify its role in SCR prevention.

Humans↗