have formed a joint venture with shared ownership and governance of Baylor Genetics (BG), which performs clinical microarray analysis and clinical exome sequencing. JRL serves on the scientific advisory board of BG. JRL has stock ownership in 23andMe, is a paid consultant for Regeneron Pharmaceuticals, and is a coinventor on multiple US and European patents related to molecular diagnostics for inherited neuropathies, eye diseases, and bacterial genomic fingerprinting (

Cytomegalovirus (CMV) subunit vaccine candidates include glycoprotein B (gB), and phosphoprotein ppUL83 (pp65). Using a guinea pig cytomegalovirus (GPCMV) model, this study compared immunogenicity, pregnancy outcome, and congenital viral infection following pre-pregnancy immunization with a three-dose series of modified vaccinia virus Ankara (MVA)- vectored vaccines consisting either of gB administered alone, or simultaneously with a pp65 homolog (GP83)-expressing vaccine. Vaccinated and control dams were challenged at midgestation with salivary gland-adapted GPCMV. Comparisons included ELISA and neutralizing antibody responses, maternal viral load, pup mortality, and congenital infection rates. Strikingly, ELISA and neutralization titers were significantly lower in the gB/GP83 combined vaccine group than in the gB group. However, both vaccines protected against pup mortality (60.5% in controls vs. 11.4% and 8.3% in gB and gB/GP83 combination groups, respectively; p<0.0001). Reductions in pup viral load were noted for both groups compared to control, but preconception vaccine resulted in a significant reduction in GPCMV transmission in the monovalent gB group only (26/44, 59 % v. 27/34, 79 % in controls; p<0.05). We conclude that, in the MVA platform, adding GP83 to a gB subunit vaccine interferes with antibody responses and diminishes protection against congenital GPCMV infection, but does not decrease protection against pup mortality.

Minichromosome maintenance protein 10 (MCM10) is essential for eukaryotic DNA replication. Here, we describe compound heterozygous MCM10 variants in patients with distinctive, but overlapping, clinical phenotypes: natural killer (NK) cell deficiency (NKD) and restrictive cardiomyopathy (RCM) with hypoplasia of the spleen and thymus. To understand the mechanism of MCM10-associated disease, we modeled these variants in human cell lines. MCM10 deficiency causes chronic replication stress that reduces cell viability due to increased genomic instability and telomere erosion. Our data suggest that loss of MCM10 function constrains telomerase activity by accumulating abnormal replication fork structures enriched with single-stranded DNA. Terminally-arrested replication forks in MCM10-deficient cells require endonucleolytic processing by MUS81, as MCM10:MUS81 double mutants display decreased viability and accelerated telomere shortening. We propose that these bi-allelic variants in MCM10 predispose specific cardiac and immune cell lineages to prematurely arrest during differentiation, causing the clinical phenotypes observed in both NKD and RCM patients.

Deoxyribonucleic acid (DNA) replication can be divided into three major steps: initiation, elongation and termination. Each time a human cell divides, these steps must be reiteratively carried out. Disruption of DNA replication can lead to genomic instability, with the accumulation of point mutations or larger chromosomal anomalies such as rearrangements. While cancer is the most common class of disease associated with genomic instability, several congenital diseases with dysfunctional DNA replication give rise to similar DNA alterations. In this review, we discuss all congenital diseases that arise from pathogenic variants in essential replication genes across the spectrum of aberrant replisome assembly, origin activation and DNA synthesis. For each of these conditions, we describe their clinical phenotypes as well as molecular studies aimed at determining the functional mechanisms of disease, including the assessment of genomic stability. By comparing and contrasting these diseases, we hope to illuminate how the disruption of DNA replication at distinct steps affects human health in a surprisingly cell-type-specific manner.

Minichromosome maintenance protein 10 (Mcm10) is essential for eukaryotic DNA replication initiation and fork stability. Recently, a compound heterozygous MCM10 mutation was identified in a patient who presented with natural killer (NK) cell deficiency.To understand the mechanism of disease, we modeled this mutation in human cell lines.We demonstrate that Mcm10 deficiency causes chronic replication stress that reduces cell viability due to increased genomic instability and telomere maintenance defects.Our data suggests that Mcm10 deficiency constrains telomerase-dependent telomere extension. This limitation can be overcome by increasing telomerase activity, although defects in telomere replication persist. We propose that stalled replication forks in Mcm10-deficient cells arrest terminally, especially within hard-to-replicate regions, and require nuclease processing involving Mus81, as MCM10:MUS81 double mutants displayed decreased viability and accelerated telomere erosion. Our results reveal that Mcm10 is critical for telomere replication and provide insights into how MCM10 mutations cause NK cell deficiency.