Disparities in late and lost: Pediatricians' role in following Pompe disease identified by newborn screening.

BACKGROUND AND OBJECTIVES: Pompe disease (PD) results from a deficiency of lysosomal acid α-glucosidase that leads to glycogen accumulation in lysosomes in multiple tissues. There are two phenotypes: infantile-onset Pompe disease (IOPD) and late-onset Pompe disease (LOPD). The objective was to evaluate the diagnostic and follow-up outcomes of children identified with PD through newborn screening (NBS) in the state of Minnesota over a 4-year period. METHODS: This study is a retrospective analysis of infants born in Minnesota between August 1, 2017, and July 31, 2021, by the Minnesota Department of Health NBS Program for Pompe disease. Newborn screening and clinical diagnostic data are summarized for all newborns with positive newborn screens for Pompe disease. RESULTS: Children with IOPD had abnormal biomarkers necessitating immediate initiation of treatment. Children with LOPD are asymptomatic to date (1.25-4.58 years) with normal biomarkers including creatine kinase, urine glucotetrasaccharides, liver function tests, and echocardiogram. The estimated birth prevalence of PD is 1:15,160. The positive predictive value for PD was 81% with a false positive rate of 1.9 per 10 positive screens. 32% of the children with LOPD were lost to follow up among which 66% were from minority ethnic groups. CONCLUSION: This emphasizes the disparity in access to health care among specific demographics, as well as the importance of a primary care provider's early involvement in educating these families. To accomplish this, and ensure equality in follow-up care, the Minnesota Pompe Disease Consortium has been formed.

Sensitivity of Dried Blood Spot Testing for Detection of Congenital Cytomegalovirus Infection.

Importance: The sensitivity of dried blood spots (DBS) to identify newborns with congenital cytomegalovirus (cCMV) infection has not been evaluated in screening studies using the current, higher-sensitivity methods for DBS processing. Objective: To assess the sensitivity of DBS polymerase chain reaction (PCR) for newborn screening for cCMV infection using saliva as the reference standard for screening, followed by collection of a urine sample for confirmation of congenital infection. Design, Setting, and Participants: This population-based cohort study took place at 5 newborn nurseries and 3 neonatal intensive care units in the Minneapolis/Saint Paul area in Minnesota from April 2016 to June 2019. Newborns enrolled with parental consent were screened for cCMV using DBS obtained for routine newborn screening and saliva collected 1 to 2 days after birth. Dried blood spots were tested for CMV DNA by PCR at both the University of Minnesota (UMN) and the US Centers for Disease Control and Prevention (CDC). Saliva swabs were tested by CMV DNA PCR at the UMN laboratory only. Newborns who screened positive by saliva or DBS had a diagnostic urine sample obtained by primary care professionals, tested by PCR within 3 weeks of birth. Analysis began July 2019. Exposures: Detection of CMV from a saliva swab using a PCR assay. Main Outcomes and Measures: Number of children with urine-confirmed cCMV and the proportion of them who were CMV positive through DBS screening. Results: Of 12 554 individuals enrolled through June 2019 (of 25 000 projected enrollment), 56 newborns were confirmed to have cCMV (4.5 per 1000 [95% CI, 3.3-5.7]). Combined DBS results from either UMN or CDC had a sensitivity of 85.7% (48 of 56; 95% CI, 74.3%-92.6%), specificity of 100.0% (95% CI, 100.0%-100.0%), positive predictive value (PPV) of 98.0% (95% CI, 89.3%-99.6%), and negative predictive value (NPV) of 99.9% (95% CI, 99.9%-100.0%). Dried blood spot results from UMN had a sensitivity of 73.2% (95% CI, 60.4%-83.0%), specificity of 100.0% (100.0%-100.0%), PPV of 100.0% (95% CI, 91.4%-100.0%), and NPV of 99.9% (95% CI, 99.8%-99.9%). Dried blood spot results from CDC had a sensitivity of 76.8% (95% CI, 64.2%-85.9%), specificity of 100.0% (95% CI, 100.0%-100.0%), PPV of 97.7% (95% CI, 88.2%-99.6%), and NPV of 99.9% (95% CI, 99.8%-99.9%). Saliva swab results had a sensitivity of 92.9% (52 of 56; 95% CI, 83.0%-97.2%), specificity of 99.9% (95% CI, 99.9%-100.0%), PPV of 86.7% (95% CI, 75.8%-93.1%), and NPV of 100.0% (95% CI, 99.9%-100.0%). Conclusions and Relevance: This study demonstrates relatively high analytical sensitivity for DBS compared with previous studies that performed population-based screening. As more sensitive DNA extraction and PCR methods continue to emerge, DBS-based testing should remain under investigation as a potential low-cost, high-throughput option for cCMV screening.