Genetic diagnosis of familial hypercholesterolaemia by targeted next-generation sequencing.

OBJECTIVES: The aim of this study was to combine clinical criteria and next-generation sequencing (pyrosequencing) to establish a diagnosis of familial hypercholesterolaemia (FH). DESIGN, SETTING AND SUBJECTS: A total of 77 subjects with a Dutch Lipid Clinic Network score of ≥ 3 (possible, probable or definite FH clinical diagnosis) were recruited from the Lipid Clinic at Sahlgrenska Hospital, Gothenburg, Sweden. Next-generation sequencing was performed in all subjects using SEQPRO LIPO RS, a kit that detects mutations in the low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), proprotein convertase subtilisin/kexin type 9 (PCSK9) and LDLR adapter protein 1 (LDLRAP1) genes; copy-number variations in the LDLR gene were also examined. RESULTS: A total of 26 mutations were detected in 50 subjects (65% success rate). Amongst these, 23 mutations were in the LDLR gene, two in the APOB gene and one in the PCSK9 gene. Four mutations with unknown pathogenicity were detected in LDLR. Of these, three mutations (Gly505Asp, Ile585Thr and Gln660Arg) have been previously reported in subjects with FH, but their pathogenicity has not been proved. The fourth, a mutation in LDLR affecting a splicing site (exon 6-intron 6) has not previously been reported; it was found to segregate with high cholesterol levels in the family of the proband. CONCLUSIONS: Using a combination of clinical criteria and targeted next-generation sequencing, we have achieved FH diagnosis with a high success rate. Furthermore, we identified a new splicing-site mutation in the LDLR gene.

Stef M. Shuster and Meredithe McNamara reply.

This letter responds to a letter by Moti Gorin in the same issue, September-October 2024, of the Hastings Center Report.

Troubling Trends in Health Misinformation Related to Gender-Affirming Care.

Amidst the misinformation climate about trans people and their health care that dominates policy and social discourse, autonomy-based rationales for gender-affirming care for trans and nonbinary youth are being called into question. In this commentary, which responds to "What Is the Aim of Pediatric 'Gender-Affirming' Care?," by Moti Gorin, we contextualize the virulent ideas circulating in misinformation campaigns that have become weaponized for unprecedented legal interference into standard health care. We conclude that the current legal justifications for upending gender-affirming care gloss over how this health care field meets conventional evidentiary standards and aligns protocols with most other fields of medicine. Refusal to offer gender-affirming care is more harmful than centralizing trans and nonbinary people's health autonomy.

Who supports Bernie? Analyzing identity and ideological variation on Twitter during the 2020 democratic primaries.

Using a novel dataset of 590M messages by 21M users, we present the first large-scale examination of the behavior of likely Bernie supporters on Twitter during the 2020 U.S. Democratic primaries and presidential election. We use these data to dispel empirically the notion of a unified, stereotypical Bernie supporter (e.g., the "Bernie Bro"). Instead, our work uncovers significant variation in the identities and ideologies of Bernie supporters who were active on Twitter. Our work makes three contributions to the literature on social media and social movements. Methodologically, we present a novel mixed methods approach to surface identity and ideological variation within a movement via use of patterns in who retweets whom (i.e. who retweets which other users) and who retweets what (i.e. who retweets which specific tweets). Substantively, documentation of these variations challenges a trend in the social movement literature to assume actors within a particular movement are unified in their ideology, identity, and values.

The Disproportionate Mental Health Burden Among Incarcerated Transgender and Gender Diverse People.

This article examines the distribution of self-reported mental health conditions and clinical contact among incarcerated transgender and gender diverse (TGD) individuals compared to cisgender women and men. Data are derived from the 2016 Survey of Prison Inmates. Results indicate that TGD respondents report more mental health symptoms, conditions, and clinical contact than their cisgender counterparts. The findings have important implications for the mental health disadvantages experienced by TGD people currently in prison.

[Heart failure in young children; a serious cause of feeding problems]. / Hartfalen bij jonge kinderen.

Feeding problems in children are usually harmless and common, but can rarely exist as a result of pathology. Heart failure is one of them and has to be recognized early because of its many consequences. We present a 15-week-old female infant who was seen at the outpatient clinic. She had already been evaluated several times by a youth doctor and general practitioner because of feeding problems and transpiration, for which several nutritional interventions had already been carried out. With no effect of nutritional interventions she was referred to a pediatrician. Physical examination showed clear signs of heart failure and echocardiogram showed a severe dilation of the left ventricle, with poor contractility of the lateral wall and papillary muscle, with end stage heart failure due to an Anomalous Left Coronary Artery from the Pulmonary Artery (ALPACA). In this article we discuss the clinical presentation of heart failure: stagnant growth, exercise intolerance, tachypnea and sometimes hepatomegaly, edema, murmurs or cyanosis. In addition, when a patient does not respond to initial therapy, we recommend to reconsider differential diagnosis and/or refer to a pediatrician.

The uneven consequences of rapid organizational change: COVID-19 and healthcare workers.

We examine the consequences of rapid organizational change on high and low-status healthcare workers (HCWs) during the COVID-19 pandemic. Drawing on 25 interviews, we found that rapid change can create a sense of social disorder by exacerbating the uncertainty brought on by the pandemic, crystallizing the lack of training to deal with crisis, and upending taken-for-granted roles and responsibilities in health infrastructures. Our work contributes to scholarship at the intersection of organizations, professions, and social studies of medicine. First, we show how organizations that must respond with rapidity, such as during a crisis, sets up workers for failure. Second, hastily made decisions can have monumental consequences in the work lives of HCWs, but with differences based on status. All HCWs had trouble with the rearrangement of tasks and roles. Low status HCWs were more likely to feel the strain of the lack of resources and direct contact with COVID-19 patients. High status HCWs were more likely to experience their autonomy undermined - in the organization and content of their work. In these contexts of rapid change, all HCWs experienced social disorder and a sense of inevitable failure, which obscured how organizations have perpetuated inequalities between high and low status workers.

Health and Health Care of Sexual and Gender Minorities.

Research on the social dimensions of health and health care among sexual and gender minorities (SGMs) has grown rapidly in the last two decades. However, a comprehensive review of the extant interdisciplinary scholarship on SGM health has yet to be written. In response, we offer a synthesis of recent scholarship. We discuss major empirical findings and theoretical implications of health care utilization, barriers to care, health behaviors, and health outcomes, which demonstrate how SGMs continue to experience structural- and interactional-level inequalities across health and medicine. Within this synthesis, we also consider the conceptual and methodological limitations that continue to beleaguer the field and offer suggestions for several promising directions for future research and theory building. SGM health bridges the scholarly interests in social and health sciences and contributes to broader sociological concerns regarding the persistence of sexuality- and gender-based inequalities.

Haplotype analyses, mechanism and evolution of common double mutants in the human LDL receptor gene.

Familial hypercholesterolemia (FH), an autosomal dominant inherited disorder resulting in increased levels of circulating plasma low-density lipoprotein (LDL), tendon xanthomas and premature coronary artery disease (CAD), is caused by defects in the LDL receptor gene (LDLR). Three widespread LDLR alterations not causing FH (c.1061-8T>C, c.2177C>T and c.829G>A) and one mutation (c.12G>A) with narrow geographical distribution and thought to cause disease were investigated. In an attempt to improve knowledge on their origin, spread and possible selective effects, estimations of the ages of these variants (t generations) and haplotype analysis were performed by genotyping 86 healthy individuals and 98 FH patients in Spain for five LDLR SNPs: c.81T>C, c.1413G>A, c.1725C>T, c.1959T>C, and c.2232G>A; most patients carried two of these LDLR variants simultaneously. It was found that both the c.1061-8T>C (t = 54) and c.2177C>T alterations (t = 62) arose at about the same time (54 and 62 generations ago, respectively) in the CGCTG haplotype, while the c.12G>A mutation (t = 70) appeared in a CGCCG haplotype carrying an earlier c.829G>A alteration (t = 83). The estimated ages of selectively neutral alterations could explain their distribution by migrations. The origin of the c.12G>A mutation could be in the Iberian Peninsula; despite its estimated age, a low selective pressure could explain its conservation in Spain from where it could have spread to China and Mexico, since the sixteenth century through the Spanish/Portuguese colonial expeditions.

Performing informed consent in transgender medicine.

Using in-depth interviews with 23 physical and mental healthcare providers and observations at transgender-specific healthcare conferences between 2012 and 2015, I examine how medical providers negotiate informed consent processes in their clinical encounters with trans patients. While a growing body of scholarship has examined informed consent in scientific research from the patient's perspective, a gap remains in how informed consent is understood in clinical encounters, and from providers' perspectives. I use the case of trans medicine, an emergent field of medicine that has not yet implemented standardized procedures or policies that shape providers' decision-making. I demonstrate how many providers of trans medicine give voice to following informed consent, but fail to actually practice it in their work with trans patients. In performing informed consent, providers revert to a paternalistic model of care, which amplifies their medical authority while veiling power differentials in their clinical encounters and decision-making in trans medicine.

p.(Asp47Asn) and p.(Thr62Met): non deleterious LDL receptor missense variants functionally characterized in vitro.

Familial Hypercholesterolemia (FH) is a common genetic disorder caused most often by mutations in the Low Density Lipoprotein Receptor gene (LDLr) leading to high blood cholesterol levels, and ultimately to development of premature coronary heart disease. Genetic analysis and subsequent cascade screening in relatives allow diagnosis of FH at early stage, especially relevant to diagnose children. So far, more than 2300 LDLr variants have been described but only a minority of them have been functionally analysed to evaluate their pathogenicity in FH. Thus, identifying pathogenic mutations in LDLr is a long-standing challenge in the field. In this study, we investigated in vitro the activity p.(Asp47Asn) and p.(Thr62Met) LDLr variants, both in the LR1 region. We used CHO-ldlA7 transfected cells with plasmids carrying p.(Asp47Asn) or p.(Thr62Met) LDLr variants to analyse LDLr expression by FACS and immunoblotting, LDL binding and uptake was determined by FACS and analysis of mutation effects was assessed in silico. The in vitro activity assessment of p.(Asp47Asn) and p.(Thr62Met) LDLr variants shows a fully functional LDL binding and uptake activities. Therefore indicating that the three of them are non-pathogenic LDLr variants. These findings also emphasize the importance of in vitro functional LDLr activity studies to optimize the genetic diagnosis of FH avoiding the report of non-pathogenic variants and possible misdiagnose in relatives if cascade screening is carried out.

Replacement of cysteine at position 46 in the first cysteine-rich repeat of the LDL receptor impairs apolipoprotein recognition.

BACKGROUND AND AIMS: Pathogenic mutations in the Low Density Lipoprotein Receptor gene (LDLR) cause Familial Hypercholesterolemia (FH), one of the most common genetic disorders with a prevalence as high as 1 in 200 in some populations. FH is an autosomal dominant disorder of lipoprotein metabolism characterized by high blood cholesterol levels, deposits of cholesterol in peripheral tissues such as tendon xanthomas and accelerated atherosclerosis. To date, 2500 LDLR variants have been identified in the LDLR gene; however, only a minority of them have been experimentally characterized and proven to be pathogenic. Here we investigated the role of Cys46 located in the first repeat of the LDL receptor binding domain in recognition of apolipoproteins. METHODS: Activity of the p.(Cys46Gly) LDLR variant was assessed by immunoblotting and flow cytometry in CHO-ldlA7 expressing the receptor variant. Affinity of p.(Cys46Gly) for LDL and VLDL was determined by solid-phase immunoassays and in silico analysis was used to predict mutation effects. RESULTS AND CONCLUSION: Functional characterization of p.(Cys46Gly) LDLR variant showed impaired LDL and VLDL binding and uptake activity. Consistent with this, solid-phase immunoassays showed the p.(Cys46Gly) LDLR variant has decreased binding affinity for apolipoproteins. These results indicate the important role of Cys46 in LDL receptor activity and highlight the role of LR1 in LDLr activity modulation. This study reinforces the significance of in vitro functional characterization of LDL receptor activity in developing an accurate approach to FH genetic diagnosis. This is of particular importance because it enables clinicians to tailor personalized treatments for patients' mutation profile.

Genotype-phenotype correlation in Costello syndrome: HRAS mutation analysis in 43 cases.

BACKGROUND: Costello syndrome (CS) is a rare multiple congenital abnormality syndrome, associated with failure to thrive and developmental delay. One of the more distinctive features in childhood is the development of facial warts, often nasolabial and in other moist body surfaces. Individuals with CS have an increased risk of malignancy, suggested to be about 17%. Recently, mutations in the HRAS gene on chromosome 11p13.3 have been found to cause CS. METHODS: We report here the results of HRAS analysis in 43 individuals with a clinical diagnosis of CS. RESULTS: Mutations were found in 37 (86%) of patients. Analysis of parental DNA samples was possible in 16 cases for both parents and in three cases for one parent, and confirmed the mutations as de novo in all of these cases. Three novel mutations (G12C, G12E, and K117R) were found in five cases. CONCLUSIONS: These results confirm that CS is caused, in most cases, by heterozygous missense mutations in the proto-oncogene HRAS. Analysis of the major phenotypic features by mutation suggests a potential correlation between malignancy risk and genotype, which is highest for patients with an uncommon (G12A) substitution. These results confirm that mutation testing for HRAS is a reliable diagnostic test for CS.

Uncertain Expertise and the Limitations of Clinical Guidelines in Transgender Healthcare.

To alleviate uncertainty in the specialized field of transgender medicine, mental and physical healthcare providers have introduced the rhetoric of evidence-based medicine (EBM) in clinical guidelines to help inform medical decision making. However there are no diagnostic tests to assess the effectiveness of transgender medical interventions and no scientific evidence to support the guidelines. Using in-depth interviews with a purposive sample of 23 healthcare providers, I found that providers invoked two strategies for negotiating the guidelines. Some used the rhetoric of EBM and closely followed clinical guidelines to contain uncertainty. Others flexibly interpreted the guidelines to embrace uncertainty. These findings raise questions about the effectiveness of EBM and guidelines in medical decision making. While trans medicine involves an identity and not a biomedical illness, providers use the same strategies to respond to uncertainty as they may in other medical arenas.

Activity-associated effect of LDL receptor missense variants located in the cysteine-rich repeats.

BACKGROUND: The LDL receptor (LDLR) is a Class I transmembrane protein critical for the clearance of cholesterol-containing lipoprotein particles. The N-terminal domain of the LDLR harbours the ligand-binding domain consisting of seven cysteine-rich repeats of approximately 40 amino acids each. Mutations in the LDLR binding domain may result in loss of receptor activity leading to familial hypercholesterolemia (FH). In this study the activity of six mutations located in the cysteine-rich repeats of the LDLR has been investigated. METHODS: CHO-ldlA7 transfected cells with six different LDLR mutations have been used to analyse in vitro LDLR expression, lipoprotein binding and uptake. Immunoblotting of cell extracts, flow cytometry and confocal microscopy have been performed to determine the effects of these mutations. In silico analysis was also performed to predict the mutation effect. RESULTS AND CONCLUSION: From the six mutations, p.Arg257Trp turned out to be a non-pathogenic LDLR variant whereas p.Cys116Arg, p.Asp168Asn, p.Asp172Asn, p.Arg300Gly and p.Asp301Gly were classified as binding-defective LDLR variants whose effect is not as severe as null allele mutations.

Mapping, characterization, and expression analysis of the SM-20 human homologue, c1orf12, and identification of a novel related gene, SCAND2.

Major psychosis was shown to segregate with a balanced translocation (1q42.1; 11q14.3) in a multigenerational family. This study describes the identification of a human SM-20 homologue gene that lies at about 400 kb on the centromeric side of the 1q42.1 breakpoint. The full-length cDNA sequence and gene structure were determined. Expression analysis was performed, showing high expression levels in skeletal and cardiac muscles; in the central nervous system, expression was restricted to dopaminergic neurons and spinal motoneurons. A second gene displaying high sequence similarity with SM-20 was also identified by BLAST. This gene, located on chromosome 15, is likely to have evolved by retroposition of SM-20 mRNA and an exon-shuffling mechanism. It encodes a 306-amino-acid protein harboring strong homology with an N-terminal motif found in some zinc-finger proteins. This gene was named SCAND2 (SCAN domain-containing 2).