Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) may reduce the risk of developing cancer-related lymphedema following axillary lymph node dissection (ALND).

Purpose: Patients undergoing axillary lymph node dissection (ALND) for breast cancer face a high risk of lymphedema, further increased by high body mass index (BMI) and insulin resistance. GLP-1 receptor agonists (GLP-1RAs) have the potential to reduce these risk factors, but their role in lymphedema has never been investigated. The purpose of this study was to determine if GLP-RAs can reduce the risk of lymphedema in patients undergoing ALND. Methods: All patients who underwent ALND at a tertiary cancer center between 2010 and 2023 were reviewed. Patients with less than 2 years of follow-up from the time of ALND were excluded. Race, BMI, radiation, chemotherapy history, pre-existing diagnosis of diabetes, lymphedema development after ALND, and the use of GLP-1RAs were analyzed. Multivariate logistic regression analysis was performed to assess if there was a significant reduction in the risk of developing lymphedema after ALND. A sub-group analysis of non-diabetic patients was also performed. Results: 3,830 patients who underwent ALND were included, 76 of which were treated with. GLP-1 RAs. The incidence of lymphedema in the GLP-1 RA cohort was 6.6% (5 patients). Compared to 28.5% (1,071 patients) in the non-GLP-1 RA cohort. On multivariate regression analysis, patients who were treated with GLP-1 RA were 86% less likely to develop lymphedema compared to the non-GLP-1 RA cohort (OR 0.14, 95% CI 0.04-0.32, p < 0.0001). A BMI of 25 kg/m 2 or greater was a statistically significant risk factor for developing lymphedema with an odds ratio of 1.34 (95% CI 1.16-1.56, p < 0.0001). Diabetes was associated with lymphedema development that closely approached statistical significance (OR 1.32, 95% CI 0.97-1.78, p = 0.06). A subgroup analysis solely on non-diabetic patients showed similar results. The odds of developing lymphedema were 84% lower for patients without diabetes treated with GLP1-RAs compared to those who did not receive GLP-1 RAs (OR 0.16, 95% CI 0.05-0.40, p < 0.0001). Conclusion: GLP1-RAs appear to significantly reduce the risk of lymphedema in patientsundergoing ALND. The mechanism of action may be multifactorial and not limited to weight reduction and insulin resistance. Future prospective analysis is warranted to clarify the role of GLP-1RAs in reducing lymphedema risk.

Genetic Testing in Craniofacial Care: Development of Algorithms for Testing Patients with Orofacial Clefting, Branchial Arch Anomalies, and Craniosynostosis.

OBJECTIVE: To develop consensus-based algorithms for genetic testing in patients with common craniofacial conditions. DESIGN: An online collaborative consisting of online meetings, independent work, and feedback across groups. Setting/Participants: A collaborative of genetics and pediatrics providers from three regional craniofacial centers (four institutions). METHODS: Collaborative participants agreed upon a shared initial framework, developed algorithms independently, and presented/tested the algorithms with a national audience. Algorithms were modified based on consensus feedback. RESULTS: The collaborative group developed final algorithms for genetic testing in patients with orofacial cleft, branchial arch conditions, and craniosynostosis. CONCLUSIONS: Timely and accurate diagnosis of genetic conditions can support medical management recommendations that result in safer surgical interventions. Algorithms can help guide best-practices for testing, particularly in institutions without easy access to genetics providers.

A high-throughput microfabricated platform for rapid quantification of metastatic potential.

Assays that measure morphology, proliferation, motility, deformability, and migration are used to study the invasiveness of cancer cells. However, native invasive potential of cells may be hidden from these contextual metrics because they depend on culture conditions. We created a micropatterned chip that mimics the native environmental conditions, quantifies the invasive potential of tumor cells, and improves our understanding of the malignancy signatures. Unlike conventional assays, which rely on indirect measurements of metastatic potential, our method uses three-dimensional microchannels to measure the basal native invasiveness without chemoattractants or microfluidics. No change in cell death or proliferation is observed on our chips. Using six cancer cell lines, we show that our system is more sensitive than other motility-based assays, measures of nuclear deformability, or cell morphometrics. In addition to quantifying metastatic potential, our platform can distinguish between motility and invasiveness, help study molecular mechanisms of invasion, and screen for targeted therapeutics.

Monitoring of estradiol levels in premenopausal women receiving adjuvant abemaciclib and ovarian function suppression.

PURPOSE: Approximately 15% of women who receive ovarian function suppression (OFS) as adjuvant treatment for high-risk, localized hormone receptor-positive (HR+) breast cancer may have inadequate estradiol suppression which can require therapeutic modification when used in combination with an aromatase inhibitor (AI). We previously reported that abemaciclib may interfere with the estradiol Abbott Alinity chemiluminescent microparticle immunoassay (CMIA) commonly used to monitor estradiol levels and suggested liquid chromatography-mass spectrometry (LC-MS/MS) is preferred in this setting. The aim of this study was to determine discrepancies in estradiol levels using CMIA compared to LC-MS/MS and subsequent treatment changes in a larger patient population. METHODS: We conducted a retrospective review of premenopausal women with early-stage HR+ breast cancer at our institution who received adjuvant OFS and abemaciclib with at least 1 CMIA estradiol level drawn during abemaciclib therapy from October 2021 to April 2023. RESULTS: Of the 22 women who met criteria for review, 20 (90.9%) had CMIA estradiol levels in the premenopausal range, of whom 9 also had estradiol measured by LC-MS/MS. All 9 women receiving OFS and abemaciclib with estradiol measurements by both methods had premenopausal range CMIA estradiol levels and postmenopausal range LC-MS/MS estradiol levels. Of the 20 patients with premenopausal estradiol levels by CMIA estradiol, treatment changes included increased OFS dosage or preparation (n = 7), change from AI to tamoxifen (n = 3), and surgical oophorectomy (n = 7). CONCLUSION: Our findings suggest the likely interference of abemaciclib with the Abbott Alinity immunoassay which may lead to unnecessary treatment changes. It is recommended that the LC-MS/MS assay be used when monitoring estradiol levels in patients receiving abemaciclib concurrently with OFS.

Book-Sharing for Toddlers with Clefts (BOOST): Protocol for a randomized controlled trial of a remote intervention to promote language development in children with cleft palate.

BACKGROUND: Children with cleft palate, with or without cleft lip (CP±L), exhibit language delays on average compared to children without clefts. Interventions to address these disparities are scarce. In this multi-center study, Book Sharing for Toddlers with Clefts (BOOST), we will test a remote, parent-focused intervention to promote language development in children with CP±L. OBJECTIVES: The study will test two primary hypotheses. First, toddlers randomized to BOOST will exhibit better language outcomes than children receiving standard-of-care (SOC). Second, we hypothesize that the BOOST program's effect on language outcomes is mediated by the frequency and quality of parent-child reading interactions. METHODS: The study is a randomized-controlled trial comparing the BOOST group to a SOC comparison group. We will enroll N = 320 English and/or Spanish-speaking children ages 24-32 months with isolated CP±L (n = 160 per group). Both groups will receive children's books, and parents will record and upload videos of themselves reading the books with their children using a smartphone app developed for the study. Parents will also complete surveys asking whether they read to their children on five randomly selected days each week. In addition, the BOOST group will participate in 3 remote dialogic book-sharing intervention sessions via Zoom. We will code book-sharing videos to assess parents' target skill usage and children's expressive language. End-of-study assessments will include measures of child language outcomes (e.g., clinician-administered measures, parent reports, and naturalistic child language samples). RESULTS: Enrollment began in April 2024 and will continue through approximately April 2028. CONCLUSION: The BOOST study will address a critical gap in the literature on interventions to improve language in children with CP±L. The results will inform the care for toddlers with oral clefts and have potential applications for other populations.

GLP-1 receptor agonist as an effective treatment for breast cancer-related lymphedema: a case report.

Introduction: Lymphedema is a major public health issue for many women undergoing breast cancer treatment. Although weight loss has been reported to be beneficial in the treatment of lymphedema, no studies to date have examined the use of GLP-1RAs for the treatment of secondary lymphedema. This case report describes a patient who experienced significant resolution of her breast cancer-related lymphedema after initiation of a GLP-1RA for weight loss. Main symptoms and/or important clinical findings: Nine months postoperatively the patient developed arm swelling and disability. While on adjuvant chemo and hormonal therapy, her weight increased dramatically and peaked 4 years later. Corresponding to her weight gain was significant worsening of her symptoms. The main diagnoses therapeutic interventions and outcomes: Due to adjuvant cancer-related weight gain and inability to lose weight with diet and exercise, she was referred for evaluation and diagnosed with lymphedema. The patient started treatment with a Glucagon-like peptide 1 receptor agonist and lost 24% of her body weight over the next 13 months. The improvement in her lymphedema mirrored her weight loss. Her limb volume difference dropped from 10.3% down to 3.4% and she no longer required a compression garment. Her imaging demonstrated return of lymphatic pumping and she experienced a significant improvement in quality of life, assessed by a validated lymphedema-specific patient reported outcome (PROM). She remains on hormonal therapy, no longer needs compression and is back to regular exercise without impairment. Conclusions: GLP-1 RAs provide a potential medical option for many patients struggling with weight gain and lymphedema. We have observed by all objective measures a significant reduction in lymphedema and the elimination of compression in the case presented as a direct result of GLP-1 RA. This may also reduce a patient's BMI to the point where they become a good candidate for lymphovenous bypass or vascularized lymph node transplant when indicated.

Is it time to reduce the length of postgraduate training for physician-scientists in internal medicine?

Physician-scientists play a crucial role in advancing medical knowledge and patient care, yet the long periods of time required to complete training may impede expansion of this workforce. We examined the relationship between postgraduate training and time to receipt of NIH or Veterans Affairs career development awards (CDAs) for physician-scientists in internal medicine. Data from NIH RePORTER were analyzed for internal medicine residency graduates who received specific CDAs (K08, K23, K99, or IK2) in 2022. Additionally, information on degrees and training duration was collected. Internal medicine residency graduates constituted 19% of K awardees and 28% of IK2 awardees. Of MD-PhD internal medicine-trained graduates who received a K award, 92% received a K08 award; of MD-only graduates who received a K award, a majority received a K23 award. The median time from medical school graduation to CDA was 9.6 years for K awardees and 10.2 years for IK2 awardees. The time from medical school graduation to K or IK2 award was shorter for US MD-PhD graduates than US MD-only graduates. We propose that the time from medical school graduation to receipt of CDAs must be shortened to accelerate training and retention of physician-scientists.

Hearing Loss Detection and Early Intervention Strategies in Kenya.

Background: Thirty-four million children globally have disabling hearing loss, with the highest prevalence in low- and middle-income countries (LMICs). Early identification and management is crucial, yet barriers to screening and treatment of hearing loss are extensive in LMICs. Unaddressed hearing loss negatively impacts individuals and communities. The WHO's 2021 World Report on Hearing urges the development of Ear and Hearing Care (EHC) programs to improve access to all aspects of care, including screening, diagnostics, management, and developmental support. A joint Nairobi- and Seattle-based group convened in 2021 to discuss strategies for program development in Kenya, as presented in this paper. Findings: Developing a national EHC program must include the necessary support services for a child with a diagnosed hearing loss, while simultaneously promoting engagement of family, community, and healthcare workers. Existing government and healthcare system policies and priorities can be leveraged for EHC programming. Strategies for success include strengthening connections between policymakers at national, county, and municipal levels and local champions for the EHC agenda, with a concurrent focus on policy, early detection and intervention, habilitation, and family-centered care. Updates to health policy and funding to support the accessibility of services and equipment should focus on leveraging national healthcare coverage for hearing technologies and services, strengthening referral pathways, training to bolster the workforce, and metrics for monitoring and evaluation. Additional strategies to support forward progress include strategic engagement of partners and leveraging local partners for phased scale-up. Conclusions and Recommendations: Recommendations to strengthen EHC within the Kenyan health system include concurrent leverage of existing health policies and priorities, partner engagement, and strengthening referral pathways, monitoring and evaluation, and training. These strategies may be generalized to other countries too.

Managing hyperglycemia and rash associated with alpelisib: expert consensus recommendations using the Delphi technique.

Hyperglycemia and rash are expected but challenging adverse events of phosphatidylinositol-3-kinase inhibition (such as with alpelisib). Two modified Delphi panels were conducted to provide consensus recommendations for managing hyperglycemia and rash in patients taking alpelisib. Experts rated the appropriateness of interventions on a 1-to-9 scale; median scores and dispersion were used to classify the levels of agreement. Per the hyperglycemia panel, it is appropriate to start alpelisib in patients with HbA1c 6.5% (diabetes) to <8%, or at highest risk for developing hyperglycemia, if they have a pre-treatment endocrinology consult. Recommend prophylactic metformin in patients with baseline HbA1c 5.7% to 6.4%. Metformin is the preferred first-line anti-hyperglycemic agent. Per the rash panel, initiate prophylactic nonsedating H1 antihistamines in patients starting alpelisib. Nonsedating H1 antihistamines and topical steroids are the preferred initial management for rash. In addition to clinical trial evidence, these recommendations will help address gaps encountered in clinical practice.

Prevalence and impact of diabetes on survival of patients with multiple myeloma in different racial groups.

ABSTRACT: Multiple myeloma (MM) is twice as common in Black individuals compared with in White individuals, and diabetes mellitus (DM) disproportionately affects Black patients. Although numerous studies have shown a correlation between DM and MM, this has not been studied in the context of race and in vivo mechanisms. We conducted a retrospective clinical study of 5383 patients with MM of which 15% had DM (White, 12% and Black, 25%). Multivariable Cox models showed reduced overall survival (OS) for patients with DM (hazard ratio, 1.27; 95% confidence interval, 1.11-1.47; P < .001). This appeared to be driven by a marked difference in OS between White patients with and without DM but not in Black patients. In contrast, obesity was associated with better OS in Black patients but not in White patients. To complement this analysis, we assessed MM growth in a genetically engineered immunocompromised nonobese diabetic (Rag1-/-/muscle creatinine kinase promoter expression of a human IGF1R [M] with a lysine [K] to arginine [R] point mutation) mouse model to evaluate the mechanisms linking DM and MM. MM.1S xenografts grew in more Rag1-/-/MKR mice and grew more rapidly in the Rag1-/-/MKR mice compared with in controls. Western blot analysis found that MM1.S xenografts from Rag1-/-/MKR mice had higher phosphorylated S6 ribosomal protein (Ser235/236) levels, indicating greater activation of the mammalian target of rapamycin pathway. Our study is, to our knowledge, the first to evaluate racial differences in DM prevalence and survival in MM, as well as the effect of DM on tumor growth in mouse models. Our results suggest that DM may contribute to the higher incidence of MM in Black patients; and to improve survival in MM, DM management cannot be ignored.

Structural insights into the career path between pre- and postgraduate physician-scientist training programs.

The growing complexities of clinical medicine and biomedical research have clouded the career path for physician-scientists. In this perspective piece, we address one of the most opaque career stage transitions along the physician-scientist career path, the transition from medical school to research-focused internal medicine residency programs, or physician-scientist training programs (PSTPs). We present the perspectives of medical scientist training program (MSTP) and PSTP directors on critical features of PSTPs that can help trainees proactively align their clinical and scientific training for successful career development. We aim to provide both trainees and MSTP directors with a conceptual framework to better understand and navigate PSTPs. We also offer interview-specific questions to help trainees gather data and make informed decisions in choosing a residency program that best supports their career.

Enhanced Thermal Conductivity of Free-Standing Double-Walled Carbon Nanotube Networks.

Nanomaterials are driving advances in technology due to their oftentimes superior properties over bulk materials. In particular, their thermal properties become increasingly important as efficient heat dissipation is required to realize high-performance electronic devices, reduce energy consumption, and prevent thermal damage. One application where nanomaterials can play a crucial role is extreme ultraviolet (EUV) lithography, where pellicles that protect the photomask from particle contamination have to be transparent to EUV light, mechanically strong, and thermally conductive in order to withstand the heat associated with high-power EUV radiation. Free-standing carbon nanotube (CNT) films have emerged as candidates due to their high EUV transparency and ability to withstand heat. However, the thermal transport properties of these films are not well understood beyond bulk emissivity measurements. Here, we measure the thermal conductivity of free-standing CNT films using all-optical Raman thermometry at temperatures between 300 and 700 K. We find thermal conductivities up to 50 W m-1 K-1 for films composed of double-walled CNTs, which rises to 257 W m-1 K-1 when considering the CNT network alone. These values are remarkably high for randomly oriented CNT networks, roughly seven times that of single-walled CNT films. The enhanced thermal conduction is due to the additional wall, which likely gives rise to additional heat-carrying phonon modes and provides a certain resilience to defects. Our results demonstrate that free-standing double-walled CNT films efficiently dissipate heat, enhancing our understanding of these promising films and how they are suited to applications in EUV lithography.

Energy expenditure in myelofibrosis patients treated with a JAK1/2 inhibitor.

Weight gain is a known adverse effect of ruxolitinib, a JAK1/2 inhibitor that is the mainstay of treatment for many patients with myelofibrosis. The mechanisms behind weight increase with ruxolitinib is incompletely understood, although decreased adipose tissue lipolysis and increased appetite due to blocking the effects of leptin in the hypothalamus have been proposed. In order to explore the metabolic changes in ruxolitinib-treated patients with myelofibrosis, we performed a pilot study to assess the feasibility of using a portable indirect calorimeter to quantify energy expenditure before and during ruxolitinib treatment and report the results of two patients. Waist circumference increased during ruxolitinib treatment in both patients. Energy expenditure initially increased followed by a decrease and then increase again, but to levels below baseline. These results suggest that weight gain secondary to ruxolitinib may be related to changes in whole body energy expenditure.

Impact of diabetes on stage I lung cancer treatment patterns and prognosis in older adults: A population-based cohort study.

Background: Diabetes is a common comorbidity in patients with early-stage non-small cell lung cancer (NSCLC), a growing population due to increased LC screening. However, it is unknown if diabetes is associated with less aggressive NSCLC treatment and worse NSCLC outcomes. This study aimed to investigate treatment patterns and outcomes of older patients with Stage I NSCLC and diabetes. Methods: Using national cancer registry data linked to Medicare, we identified patients ≥65 years old with Stage I NSCLC. Patients were categorized as having no diabetes, diabetes without severe complications (DM-c), or diabetes with ≥1 severe complication (DM + c). We used multinomial logistic regression to assess the association of diabetes and NSCLC treatment. The association of diabetes category with NSCLC and non-NSCLC survival was analyzed with Fine-Grey competing-risks regression. Results: In 25,358 patients (75% no diabetes, 12% DM-c and 13% had DM + c), adjusted analyses showed that DM-c and DM + c were associated with increased odds of receiving limited resection rather than lobectomy (odds ratio [OR]: 1.22, 95% confidence interval [CI]: 1.07-1.37 and OR 1.42, 95% CI 1.26-1.59, respectively). Competing risk regression showed diabetes was associated with increased risk of non-NSCLC death (DM-c hazard ratio [HR] 1.16, 95% CI: 1.08-1.25, DM + c HR 1.49, 95% CI: 1.40-1.59), but not NSCLC-specific death. Conclusion: This study uncovers critical information on how diabetes is associated with less aggressive early-stage NSCLC care in older patients. This study also confirms that diabetes increases death from non-lung cancer causes and managing comorbidities is crucial to improving outcomes in older early-stage NSCLC survivors.

Isolated frontosphenoidal craniosynostosis: An argument for genetic testing.

Isolated frontosphenoidal craniosynostosis (IFSC) is a rare congenital defect defined as premature fusion of the frontosphenoidal suture in the absence of other suture fusion. Until now, IFSC was regarded as a phenomenon with an unclear genetic etiology. We have identified three cases with IFSC with underlying syndromic diagnoses that were attributable to pathogenic mutations involving FGFR3 and MN1, as well as 22q11.2 deletion syndrome. These findings suggest a genetic predisposition to IFSC may exist, thereby justifying the recommendation for genetic evaluation and testing in this population. Furthermore, due to improved imaging resolution, cases of IFSC are now readily identified. With the identification of IFSC with underlying genetic diagnoses, in combination with significant improvements in imaging resolution, we recommend genetic evaluation in children with IFSC.

Optimal Management of Insulin in Patients Undergoing 18F-Fluorodeoxyglucose Positron Emission Tomography Scans.

OBJECTIVE: The management of insulin injections and insulin pumps before 18F-fluorodeoxyglucose-positron emission tomography integrated computerized tomography (FDG-PET/CT) scans is an important area to investigate given the rising rate of diabetes, the significant association between diabetes and cancer, and the complex relationship among glucose, insulin, and FDG tumor uptake. The purpose of this study was to determine the recommendations around subcutaneous insulin administration, insulin pumps, and hybrid closed-loop systems before FDG-PET scans. METHODS: We examined the websites of 100 hospitals selected from the 2022 US News and World Report top cancer hospitals for specific strategies around diabetes medication management before FDG-PET/CT scans. RESULTS: Of the 100 hospital websites, 61 had instructions addressing patients with diabetes. Of the 61 hospitals, 47.5% (n = 29) referred patients to their provider for further instructions, 18% (n = 11) referred patients to their own internal radiology department for further instructions, 16.4% (n = 10) had instructions on oral diabetic medications, 23% (n = 14) had instructions on insulin, and 3.3% (n = 2) had instructions on insulin pump management. Most commonly, instructions were to stop insulin 3 to 4 hours before the study and direct patients to their referring provider for more detailed instructions (n = 7). CONCLUSION: There is a lack of guidance and consensus among US cancer hospitals on managing insulin and continuous subcutaneous insulin infusions before FDG-PET/CT studies and a majority rely on referring providers to advise patients. However, society guidelines offer inconsistent recommendations and little research has been carried out to help guide referring providers. A multidisciplinary panel of specialists could help to guide practitioners on optimal management.

Discrepancies in estradiol levels in a premenopausal woman receiving abemaciclib despite ovarian function suppression and bilateral salpingo-oophorectomy.

Abemaciclib is approved for use in the adjuvant setting in combination with endocrine therapy for patients with high-risk, hormone receptor-positive, HER2-negative early-stage breast cancer based on the monarchE trial. Options for endocrine therapy for premenopausal women include an aromatase inhibitor with ovarian function suppression or tamoxifen with or without ovarian suppression. We describe a unique case of a premenopausal woman with early-stage breast cancer receiving adjuvant abemaciclib and an aromatase inhibitor with elevated estradiol levels as measured by the Abbott Alinity chemiluminescent immunoassay despite chemical and surgical ovarian function suppression. Given low estradiol levels using liquid chromatography-mass spectrometry testing following a bilateral salpingo-oopherectomy, our case report suggests an interference of abemaciclib with the Abbott Alinity immunoassay. This possible interference has significant impacts on clinical care as false elevations in estradiol levels measured by immunoassays can lead to unnecessary treatment changes, including surgery.

Subjective social status, race, and metabolic syndrome in women with breast cancer.

PURPOSE: To evaluate the association of subjective social status (SSS) with metabolic syndrome (MetS) severity and its potential contribution to racial health disparities in women with breast cancer. METHODS: Multicenter cross-sectional study (10 US hospitals) in women (n = 1206) with primary diagnosis of invasive breast cancer received during Mar/2013-Feb/2020. Participants, self-identified as non-Hispanic White or Black, underwent physical and laboratory examinations and survey questions assessing socioeconomic parameters, medical history, and behavioral risks. SSS was measured with the 10-rung MacArthur scale. MetS severity was measured with a validated Z-Score. Generalized linear mixed modeling was used to analyze the associations. Missing data were handled using multiple imputation. RESULTS: Average age was 58 years. On average, the SSS of Black women, given equivalent level of income and education, was lower than the SSS of White women: 6.6 (6.1-7.0) vs 7.7 (7.54-7.79) among college graduates and 6.8 (6.4-7.2) vs 7.6 (7.5-7.8) among women in the high-income category (> $75,000). In multivariable analysis, after controlling for age, income, education, diet, and physical activity, increasing SSS was associated with a decrease in MetS-Z score, - 0.10 (- 0.16 to - 0.04) per every 2 rung increase in the MacArthur scale. CONCLUSION: Black women with breast cancer rank their SSS lower than White women with breast cancer do at each level of income and education. As SSS is strongly associated with MetS severity these results identify potentially modifiable factors that contribute to racial disparities.

POLR1A variants underlie phenotypic heterogeneity in craniofacial, neural, and cardiac anomalies.

Heterozygous pathogenic variants in POLR1A, which encodes the largest subunit of RNA Polymerase I, were previously identified as the cause of acrofacial dysostosis, Cincinnati-type. The predominant phenotypes observed in the cohort of 3 individuals were craniofacial anomalies reminiscent of Treacher Collins syndrome. We subsequently identified 17 additional individuals with 12 unique heterozygous variants in POLR1A and observed numerous additional phenotypes including neurodevelopmental abnormalities and structural cardiac defects, in combination with highly prevalent craniofacial anomalies and variable limb defects. To understand the pathogenesis of this pleiotropy, we modeled an allelic series of POLR1A variants in vitro and in vivo. In vitro assessments demonstrate variable effects of individual pathogenic variants on ribosomal RNA synthesis and nucleolar morphology, which supports the possibility of variant-specific phenotypic effects in affected individuals. To further explore variant-specific effects in vivo, we used CRISPR-Cas9 gene editing to recapitulate two human variants in mice. Additionally, spatiotemporal requirements for Polr1a in developmental lineages contributing to congenital anomalies in affected individuals were examined via conditional mutagenesis in neural crest cells (face and heart), the second heart field (cardiac outflow tract and right ventricle), and forebrain precursors in mice. Consistent with its ubiquitous role in the essential function of ribosome biogenesis, we observed that loss of Polr1a in any of these lineages causes cell-autonomous apoptosis resulting in embryonic malformations. Altogether, our work greatly expands the phenotype of human POLR1A-related disorders and demonstrates variant-specific effects that provide insights into the underlying pathogenesis of ribosomopathies.

Hallermann-Streiff Syndrome in Concordant Monozygotic Twins With Congenital Cataracts, Exudative Retinal Detachments, and One Case of Corneal Perforation Requiring Keratoplasty.

PURPOSE: We describe the management of Hallermann-Streiff syndrome in monozygotic female twins with congenital cataracts, exudative retinal detachments, and 1 case of corneal descemetocele with associated dellen and subsequent perforation. METHODS: This study was a case report and review of the literature. RESULTS: Twins 1 and 2 exhibited all 7 cardinal characteristics of Hallermann-Streiff syndrome, presenting with spontaneous lenticular resorption, anterior uveitis, and glaucoma. They underwent bilateral cataract extraction with near total capsulectomy. Both twins experienced recurrent glaucoma, for which twin 1 underwent successful endocyclophotocoagulation in both eyes and twin 2 in the left eye alone. The fellow eye developed 2 sites of perilimbal corneal descemetoceles with associated dellen at the inferotemporal limbal corneal junction leading to spontaneous perforation of 1 site, requiring a full-thickness corneal graft. Both twins developed recurrent bilateral exudative retinal detachments unresponsive to oral prednisolone. Twin 1's last best-corrected visual acuity with aphakic spectacles was 20/260 in the right eye and 20/130 in the left eye at age 4 years and 8 months. Twin 2's last best-corrected visual acuity was 20/130 in each eye at age 4 years and 11 months, over a year after right eye penetrating keratoplasty. CONCLUSIONS: We describe 2 rare cases of Hallermann-Streiff syndrome in monozygotic twins complicated by corneal perforation requiring penetrating keratoplasty in 1 eye of 1 twin. Although corneal opacities have been described in this condition, this is the first case of corneal descemetocele in Hallermann-Streiff syndrome. The cornea was stabilized with a relatively favorable visual outcome over 1 year later.