Biochemical signatures of disease severity in multiple sulfatase deficiency.

Sulfatases catalyze essential cellular reactions, including degradation of glycosaminoglycans (GAGs). All sulfatases are post-translationally activated by the formylglycine generating enzyme (FGE) which is deficient in multiple sulfatase deficiency (MSD), a neurodegenerative lysosomal storage disease. Historically, patients were presumed to be deficient of all sulfatase activities; however, a more nuanced relationship is emerging. Each sulfatase may differ in their degree of post-translational modification by FGE, which may influence the phenotypic spectrum of MSD. Here, we evaluate if residual sulfatase activity and accumulating GAG patterns distinguish cases from controls and stratify clinical severity groups in MSD. We quantify sulfatase activities and GAG accumulation using three complementary methods in MSD participants. Sulfatases differed greatly in their tolerance of reduction in FGE-mediated activation. Enzymes that degrade heparan sulfate (HS) demonstrated lower residual activities than those that act on other GAGs. Similarly, HS-derived urinary GAG subspecies preferentially accumulated, distinguished cases from controls, and correlated with disease severity. Accumulation patterns of specific sulfatase substrates in MSD provide fundamental insights into sulfatase regulation and will serve as much-needed biomakers for upcoming clinical trials. This work highlights that biomarker investigation of an ultra-rare disease can simultaneously inform our understanding of fundamental biology and advance clinical trial readiness efforts.

Educating military primary health-care providers in genomic medicine: lessons learned from the MilSeq Project.

PURPOSE: With few trained genetics professionals, the Military Health System is ill-equipped to manage the rapid expansion of genomic medicine. The MilSeq Project introduces an alternative service delivery model (ASDM) in which primary health-care providers (HCPs) provide post-test counseling (PTC) to healthy Airmen who have undergone exome sequencing. We describe HCP performance after a prerequisite educational intervention (EI). METHODS: After a brief EI and pre-/posteducation surveys, HCPs were eligible to provide PTC with a genetic counselor available for consult. PTC was recorded, transcribed, and reviewed. Opportunities for improvement were organized into four error adjustment categories: (1) knowledge limitation, (2) minor, (3) moderate, and (4) critical. Thematic analysis was also performed. RESULTS: Pre-/posteducation survey responses revealed statistically significant improvements in all domains. Minor error adjustments were most represented (n = 93), followed by knowledge limitation (n = 39) and moderate (n = 19). No critical errors were identified, and 17 transcripts required no adjustment. Thematic analysis revealed four themes that would benefit from more focused education: (1) family-centered care, (2) conveying risk, (3) disease knowledge, and (4) assay knowledge. CONCLUSION: HCPs demonstrated competence in basic PTC after a brief EI. This ASDM may be a viable interim response to the shortage of genetics professionals in some systems.

Airmen and health-care providers' attitudes toward the use of genomic sequencing in the US Air Force: findings from the MilSeq Project.

PURPOSE: The use of genomic sequencing (GS) in military settings poses unique considerations, including the potential for GS to impact service members' careers. The MilSeq Project investigated the use of GS in clinical care of active duty Airmen in the United States Air Force (USAF). METHODS: We assessed perceived risks, benefits, and attitudes toward use of GS in the USAF among patient participants (n = 93) and health-care provider participants (HCPs) (n = 12) prior to receiving or disclosing GS results. RESULTS: Participants agreed that there are health benefits associated with GS (90% patients, 75% HCPs), though more HCPs (75%) than patients (40%) agreed that there are risks (p = 0.048). The majority of both groups (67% HCPs, 77% patients) agreed that they trust the USAF with genetic information, but far fewer agreed that genetic information should be used to make decisions about deployment (5% patients, 17% HCPs) or duty assignments (3% patients, 17% HCPs). Despite their hesitancy, patients were supportive of the USAF testing for nondisease traits that could impact their duty performance. Eighty-seven percent of patients did not think their GS results would influence their career. CONCLUSION: Results suggest favorable attitudes toward the use of GS in the USAF when not used for deployment or assignment decisions.

Natural history of multiple sulfatase deficiency: Retrospective phenotyping and functional variant analysis to characterize an ultra-rare disease.

Multiple sulfatase deficiency (MSD) is an ultra-rare neurodegenerative disorder caused by pathogenic variants in SUMF1. This gene encodes formylglycine-generating enzyme (FGE), a protein required for sulfatase activation. The clinical course of MSD results from additive effect of each sulfatase deficiency, including metachromatic leukodystrophy (MLD), several mucopolysaccharidoses (MPS II, IIIA, IIID, IIIE, IVA, VI), chondrodysplasia punctata, and X-linked ichthyosis. While it is known that affected individuals demonstrate a complex and severe phenotype, the genotype-phenotype relationship and detailed clinical course is unknown. We report on 35 cases enrolled in our retrospective natural history study, n = 32 with detailed histories. Neurologic function was longitudinally assessed with retrospective scales. Biochemical and computational modeling of novel SUMF1 variants was performed. Genotypes were classified based on predicted functional change, and each individual was assigned a genotype severity score. The median age at symptom onset was 0.25 years; median age at diagnosis was 2.7 years; and median age at death was 13 years. All individuals demonstrated developmental delay, and only a subset of individuals attained ambulation and verbal communication. All subjects experienced an accumulating systemic symptom burden. Earlier age at symptom onset and severe variant pathogenicity correlated with poor neurologic outcomes. Using retrospective deep phenotyping and detailed variant analysis, we defined the natural history of MSD. We found that attenuated cases can be distinguished from severe cases by age of onset, attainment of ambulation, and genotype. Results from this study can help inform prognosis and facilitate future study design.

Automated typing of red blood cell and platelet antigens from whole exome sequences.

BACKGROUND: Genotyping has expanded the number red blood cell (RBC) and platelet (PLT) antigens that can readily be typed, but often represents an additional testing cost. The analysis of existing genomic data offers a cost-effective approach. We recently developed automated software (bloodTyper) for determination of RBC and PLT antigens from whole genome sequencing. Here we extend the algorithm to whole exome sequencing (WES). STUDY DESIGN AND METHODS: Whole exome sequencing was performed on samples from 75 individuals. WES-based bloodTyper RBC and PLT typing was compared to conventional polymerase chain reaction (PCR) RHD zygosity testing and serologic and single-nucleotide polymorphism (SNP) typing for 38 RBC antigens in 12 systems (17 serologic and 35 SNPs) and 22 PLT antigens (22 SNPs). Samples from the first 20 individuals were used to modify bloodTyper to interpret WES followed by blinded typing of 55 samples. RESULTS: Over the first 20 samples, discordances were noted for C, M, and N antigens, which were due to WES-specific biases. After modification, bloodTyper was 100% accurate on blinded evaluation of the last 55 samples and outperformed both serologic (99.67% accurate) and SNP typing (99.97% accurate) reflected by two Fyb and one N serologic typing errors and one undetected SNP encoding a Jknull phenotype. RHD zygosity testing by bloodTyper was 100% concordant with a combination of hybrid Rhesus box PCR and PCR-restriction fragment length polymorphism for all samples. CONCLUSION: The automated bloodTyper software was modified for WES biases to allow for accurate RBC and PLT antigen typing. Such analysis could become a routing part of future WES efforts.

Complex care of individuals with multiple sulfatase deficiency: Clinical cases and consensus statement.

Multiple sulfatase deficiency (MSD) is an ultra-rare neurodegenerative disorder that results in defective sulfatase post-translational modification. Sulfatases in the body are activated by a unique protein, formylglycine-generating enzyme (FGE) that is encoded by SUMF1. When FGE is absent or insufficient, all 17 known human sulfatases are affected, including the enzymes associated with metachromatic leukodystrophy (MLD), several mucopolysaccharidoses (MPS II, IIIA, IIID, IVA, VI), chondrodysplasia punctata, and X-linked ichthyosis. As such, individuals demonstrate a complex and severe clinical phenotype that has not been fully characterized to date. In this report, we describe two individuals with distinct clinical presentations of MSD. Also, we detail a comprehensive systems-based approach to the management of individuals with MSD, from the initial diagnostic evaluation to unique multisystem issues and potential management options. As there have been no natural history studies to date, the recommendations within this report are based on published studies and consensus opinion and underscore the need for future research on evidence-based outcomes to improve management of children with MSD.

Correction to: Manifesting heterozygotes in McArdle disease: a myth or a reality-role of statins.

Unfortunately the name of one of the authors was spelled incorrectly in the published original article. The correct name is Alejandro Santos-Lozano. The original article got updated.

Manifesting heterozygotes in McArdle disease: a myth or a reality-role of statins.

McArdle disease is an autosomal recessive condition caused by deficiency of the PYGM gene-encoded muscle isoform of glycogen phosphorylase. Some cases of "manifesting" heterozygotes or carriers (i.e., patients who show some McArdle-like symptoms or signs despite being carriers of only one mutated PYGM allele) have been reported in the literature but there is controversy, with misdiagnosis being a possibility. The purpose of our study was to determine if there are actually "manifesting" heterozygotes of McArdle disease and, if existing, whether statin treatment can trigger such condition. Eighty-one relatives of McArdle patients (among a total of 16 different families) were studied. We determined whether they were carriers of PYGM mutations and also collected information on exercise tests (second wind and modified Wingate anaerobic test) and statin intake. We found 50 carriers and 31 non-carriers of PYGM mutations. Although we found existence of heterozygotes manifesting some exercise-related muscle problems such as exacerbated myalgia or weakness, they only accounted for 14% of the carriers and muscle symptoms were milder than those commonly reported in patients. Further, no carrier (whether reporting symptoms or not) showed the second wind phenomenon or a flat blood lactate response to maximal-intensity exercise, both of which are hallmarks of McArdle disease. On the other hand, statin myotoxicity was not associated with muscle symptom onset.

Mandibular canal branching assessed with cone beam computed tomography.

PURPOSE: The mandibular canal must be considered in dental procedures to avoid injuries of the alveolar inferior nerve. The occurrence of anatomical variations of the mandibular canal increases the risk of neurovascular injuries. The purpose of this study was to identify and describe the prevalence of mandibular canal branching (MCB) using cone beam computer tomography (CBCT). METHODS: Seven hundred standardized CBCTs were selected. The images were evaluated for the presence of MCB and for the detection of pathologies that could affect the structure of the canals. The data were analyzed using descriptive statistics and the Chi-squared test. RESULTS: The prevalence of MCB was 41.1%. There was no statistical difference between genders with the presence of the branches (p > 0.005). The highest prevalence was in the premolar and retromolar regions. Pathologies found in the molar region were frequently connected with MCB (77.8%), and the most common pathology related to branches was periapical lesion. CONCLUSIONS: Mandibular canal branching presented a high prevalence in CBCT imagery, more frequently located in regions of the premolar and retromolar. An adequate diagnosis of the MCB is necessary to perform dental procedures and verify possible associated pathologies.

Determining the prevalence of McArdle disease from gene frequency by analysis of next-generation sequencing data.

PURPOSE: McArdle disease is one of the most common glycogen storage disorders. Although the exact prevalence is not known, it has been estimated to be 1 in 100,000 patients in the United States. More than 100 mutations in PYGM have been associated with this disorder. McArdle disease has significant clinical variability: Some patients present with severe muscle pain and weakness; others have only mild, exercise-related symptoms. METHODS: Next-generation sequencing data allow estimation of disease prevalence with minimal ascertainment bias. We analyzed gene frequencies in two cohorts of patients based on exome sequencing results. We categorized variants into three groups: a curated set of published mutations, variants of uncertain significance, and likely benign variants. RESULTS: An initial estimate based on the frequency of six common mutations predicts a disease prevalence of 1/7,650 (95% confidence interval (CI) 1/5,362-1/11,108), which greatly deviates from published estimates. A second method using the two most common mutations predicts a prevalence of 1/42,355 (95% CI 1/24,536-1/76,310) in Caucasians. CONCLUSIONS: These results suggest that the currently accepted prevalence of McArdle disease is an underestimate and that some of the currently considered pathogenic variants are likely benign.

Assessing Clinical Utility of Pharmacogenetic Testing in the Military Health System.

INTRODUCTION: Response to medications can differ widely among individual patients. Adverse drug reactions can lead to serious morbidity and mortality. Pharmacogenetic (PGx) testing can predict responses to medications and increased risks of adverse events where the genetic basis is understood. Several published manuscripts suggest positive impacts of systematic preemptive PGx testing. However, few studies have been conducted on PGx implementation in the Military Health System (MHS). MATERIAL AND METHODS: A cross-sectional study of adult beneficiaries in a primary care clinic at a large military treatment facility was conducted in 2022. Participants underwent PGx genotyping of CYP2C19 and CYP2D6 genes at the Defense Health Agency Genetics Reference Laboratory. Participant medication lists were compared to the current Clinical Pharmacogenetic Implementation Consortium (CPIC) PGx gene-drug guidelines to assess potential actionability of these results. RESULTS: Genotyping of CYP2C19 and CYP2D6 in 165 MHS beneficiaries (mean age: 65 years) revealed that 81.2% of participants had at least one abnormal PGx finding. Among those with an abnormal PGx result, 65% were taking a medication listed on the CPIC website with an association with the particular gene in which the finding was identified. In addition, 78% of all of the participants in the study were taking at least one medication that is metabolized by CYP2C19 or CYP2D6 with associated CPIC guidelines. CONCLUSIONS: Pharmacogenetic testing for CYP2C19 and CYP2D6 identified a substantial proportion of MHS patients at a single center who could benefit from evaluation of current medication regimens based on the CPIC guidelines. Individualized medical management may be warranted to a greater degree than previously recognized based on the findings given possible differences in medication metabolism. Many MHS beneficiaries already take medications metabolized by CYP2C19 and CYP2D6, and a substantial proportion may be at risk for preventable adverse events for medications metabolized by these enzymes. While preliminary, a large number of actionable polymorphisms among a relatively small set of individuals taking at-risk medications suggest that implementing PGx testing in clinical practice may be beneficial in the MHS with appropriate clinical infrastructure.

Surveying the Genomic Landscape Supporting the Development of Precision Military Aerospace Medicine.

INTRODUCTION: Precision medicine is an approach to healthcare that is modifying clinical management by leveraging technological advances in genomics that assess a patient's genetic information to identify unique predispositions. While the civilian sector is integrating genomics widely to personalize diagnosis and treatment, the military medical environment has reacted more slowly. The operational requirements of military service encourage a tailored approach for focusing military precision medicine on occupation-specific conditions. Here, we present a survey of the genomic landscape related to military aerospace medicine.METHODS: We collated observations from genome-wide association studies (GWAS) relating genetic markers to conditions that may negatively influence flight operations and for which the U.S. Air Force School of Aerospace Medicine's Aeromedical Consult Service (ACS) provides aeromedical waiver guidance. Our sources for identifying relevant literature were the GWAS Catalog, the Atlas of GWAS Summary Statistics, and PubMed/Google Scholar searches.RESULTS: Using the ACS guidance as a starting point, we found 1572 papers describing 84 clinical conditions with genetic associations. The earliest aeromedical GWAS publication was in 2006, increasing to 225 publications in 2019. We identified 42,020 polymorphisms from more than 84 million participants across the studies.CONCLUSION: Our study revealed areas where deeper investigations into how genetic markers manifest in clinical diagnosis, prevention, or risk management could lead to increased medical readiness. Additionally, our results show those clinical areas for which guidance could include genetic risk considerations.Chapleau RR, Regn DD, de Castro MJ. Surveying the genomic landscape supporting the development of precision military aerospace medicine. Aerosp Med Hum Perform. 2022; 93(2):89-93.

Evaluation of the Maxillary Sinus of Patients with Maxillary Posterior Implants: A CBCT Cross-Sectional Study.

BACKGROUND: During oral rehabilitation, dental implants in the posterior maxilla can penetrate the maxillary sinus. The aim was to evaluate the presence of maxillary sinus abnormalities in patients with dental implants in the posterior maxillary region using cone-beam computed tomography (CBCT) images. MATERIALS AND METHODS: This was a retrospective cross-sectional study, and CBCT scans of 199 patients (459 dental implants) were evaluated. Implants were assessed according to their relative location to the maxillary sinus floor (up to 2 mm from the maxillary sinus cortex, within 2 mm to intimate contact with the maxillary sinus cortex, apical third inside the maxillary sinus, two-thirds or more inside the maxillary sinus) and bone-fixation tissue (Alveolar ridge or Bone graft). Maxillary sinus abnormalities were classified. Kappa and Weighted Kappa and the Kruskal-Wallis test were applied. RESULTS: A higher prevalence of mucosal thickening and non-specific opacification were observed in implants located within 2 mm to intimate contact with the cortex of the maxillary sinus floor. Of the 66 implants with apical thirds located inside the maxillary sinus, 31 (46.7%) were associated with sinus abnormalities and of all implants (n = 5) with two-thirds or more located inside the maxillary sinus, all of these were associated with sinus abnormalities. No association was observed in relation to implant bone-fixation tissue. CONCLUSIONS: This study found a significant association between dental implant placement near or within the sinus and sinus abnormalities, mainly mucosal thickening and non-specific opacification.

Precision Medicine-A Demand Signal for Genomics Education.

Pressed by the accumulating knowledge in genomics and the proven success of the translation of cancer genomics to clinical practice in oncology, the Obama administration unveiled a $215 million commitment for the Precision Medicine Initiative (PMI) in 2016, a pioneering research effort to improve health and treat disease using a new model of patient-powered research. The objectives of the initiative include more effective treatments for cancer and other diseases, creation of a voluntary national research cohort, adherence to privacy protections for maintaining data sharing and use, modernization of the regulatory framework, and forging public-private partnerships to facilitate these objectives. Specifically, the DoD Military Health System joined other agencies to execute a comprehensive effort for PMI. Of the many challenges to consider that may contribute to the implementation of genomics-lack of familiarity and understanding, poor access to genomic medicine expertise, needs for extensive informatics and infrastructure to integrate genomic results, privacy and security, and policy development to address the unique requirements of military medical practice-we will focus on the need to establish education in genomics appropriate to the provider's responsibilities. Our hypothesis is that there is a growing urgency for the development of educational experiences, formal and informal, to enable clinicians to acquire competency in genomics commensurate with their level of practice. Several educational approaches, both in practice and in development, are presented to inform decision-makers and empower military providers to pursue courses of action that respond to this need.

Return of secondary findings in genomic sequencing: Military implications.

BACKGROUND: Genomic sequencing has become a widely used tool in clinical and research settings in both civilian and military healthcare systems. METHODS: In this paper, we consider potential military-specific implications of returning genomic sequencing secondary findings to ensure the proper protections, policies, and processes are in place for the use of this information. RESULTS: We specifically use two examples to highlight potential military implications of the return of secondary findings. CONCLUSION: Clinicians and researchers are strongly encouraged to consider the military implications of the return of results for informed consent of service members or their families undergoing clinical or research genomic sequencing.

Military genomics: a perspective on the successes and challenges of genomic medicine in the Armed Services.

We describe the impact genomics has on the health and readiness of the military service member, highlight several examples of the current and future plans for genomic medicine within the military, discuss challenges to implementation and provide recommendations to address some of those challenges.