Devin Oglesbee | PubMed Health

PubMed2025

Reduction of false-positive results with biochemical second-tier testing for newborn screening of Pompe disease.

PURPOSE: To review the performance and outcomes of a second-tier newborn screening test for Pompe disease. METHODS: We followed our previously published screening approach that reduces false-positive results by incorporating creatine and creatinine levels and postanalytic tools in a second-tier test. RESULTS: We reviewed 1879 blood samples from neonates born in 11 states. Second-tier testing effectively reduced false-positive results, compared with first-tier enzyme testing alone. Only a small number of screen-positive cases (n = 7) were confirmed to have infantile-onset Pompe disease. No false-negative cases of infantile-onset Pompe disease were identified in this cohort, and 6 cases of possible late-onset Pompe disease were not detected with this approach. CONCLUSION: This tiered screening strategy discriminated well between true- and false-positive results and improved the positive predictive value. However, it did not reliably differentiate between infantile- and late-onset Pompe disease.

Humans↗

PubMed2025

Rethinking the pathogenicity of intragenic DMD duplications detected by carrier screening: High prevalence of nontandem duplications revealed by long-read sequencing.

PURPOSE: The pathogenicity of intragenic duplications depends on their structural configuration. Tandem duplications often disrupt reading frames and cause gene loss of function, whereas interspersed (nontandem) duplications are largely benign. When the configuration cannot be determined, current guidelines presume a tandem structure, leading to some laboratories automatically classifying such variants as likely pathogenic or pathogenic. This study evaluates the validity of this presumption for DMD, in patients with and without clinical indications of dystrophinopathy. METHODS: We performed high-coverage long-read genome sequencing on 15 patients with intragenic DMD duplications. A total of 4 patients had clinically indicated dystrophinopathy testing, whereas in the remaining 11 patients, the duplications were detected without clear indications of dystrophinopathy (eg, through carrier screening). RESULTS: All 4 patients with clinical indications had tandem duplications. In contrast, 64% (7/11) of the cases without such indications had interspersed duplications, with 4 subsequently reclassified as likely benign, 2 (likely) pathogenic, and 1 uncertain. These duplications were often complex, involving coduplications or codeletions with other regions. CONCLUSION: Our findings challenge the presumption that intragenic DMD duplications are predominantly in tandem. This highlights the need for a cautious variant interpretation approach, particularly in carrier screening and other settings in which variants are identified without indications of dystrophinopathy.

Humans↗