Rare Gene Mutations Research Articles

A polygenic risk score derived from common variants of monogenic diabetes genes is associated with young-onset type 2 diabetes and cardiovascular-kidney complications.

Monogenic diabetes is caused by rare mutations in genes usually implicated in beta cell biology. Common variants of monogenic diabetes genes (MDG) may jointly influence the risk of young-onset type 2 diabetes (YOD, diagnosed before the age of 40 years) and cardiovascular and kidney events. Using whole-exome sequencing data, we constructed a weighted polygenic risk score (wPRS) consisting of 135 common variants (minor allele frequency >0.01) of 34 MDG based on r2>0.2 for linkage disequilibrium in a discovery case-control cohort of 453 adults with YOD (median [IQR] age 39.7 [34.9-46.9] years) and 405 without YOD (median [IQR] age 56.7 [50.3-61.0] years), followed by validation in an independent cross-sectional cohort with array-based genotyping for YOD and a prospective cohort of individuals with type 2 diabetes for cardiovascular and kidney events. In the discovery cohort, the OR of the 135 common variants for YOD ranged from 1.00 to 2.61. In the validation cohort (920 YOD and 4910 non-YOD), top-10%-wPRS was associated with an OR of 1.42 (95% CI 1.03, 1.95, p=0.033) for YOD compared with bottom-10%-wPRS. In 2313 individuals with type 2 diabetes (median [IQR]: age 53.4 [45.4-61.7] years; disease duration 4.0 [1.0-9.0] years) observed for a median (IQR) of 17.5 (14.4-21.8) years, standardised wPRS was associated with increased HR for incident cardiovascular events (1.16 [95% CI 1.06, 1.27], p=0.001), kidney events (1.09 [95% CI 1.02, 1.16], p=0.013) and cardiovascular-kidney events (1.10 [95% CI 1.03, 1.16], p=0.003). Using the 'bottom-20%-wPRS plus baseline disease duration <5 years' group as referent, the 'top-20%-wPRS plus baseline disease duration 5 to <10 years' group had unadjusted and adjusted HR of 1.60 (95% CI 1.17, 2.19, p=0.003) and 1.62 (95% CI 1.16, 2.26, p=0.005), respectively, for cardiovascular-kidney events compared with 1.38 (95% CI 0.97, 1.98, p=0.075) and 1.06 (95% CI 0.72, 1.57, p=0.752) in the 'bottom-20%-wPRS plus baseline disease duration ≥10 years' group. Common variants of MDG increased risk for YOD and cardiovascular-kidney events.

Pregnancy in Primary Ovarian Insufficiency and Hypoplastic Uterus: Case Series

Primary ovarian insufficiency (POI) in women of reproductive age remains unexplained in nearly 90% of cases. Various infections (e.g., mumps, varicella, malaria, shigella, tuberculosis) can destroy healthy ovarian tissue. Rare mutations in genes for FSH and LH receptors, chromosomal abnormalities (e.g., Turner Syndrome, Mosaic Turners, Fragile X FMR1 premutation), and autoimmune diseases (e.g., Addison disease, Hashimoto thyroiditis, rheumatoid arthritis, systemic lupus erythematosus) are also associated with POI. Genetic mutations and autosomal recessive diseases like galactosemia contribute to POI as well. The overall success rate for pregnancy and live birth after assisted reproductive techniques is only 25%. Women with POI should be informed about their condition and future fertility treatment options. For women desiring fertility, cyclical bleeding is preferred to maximize chances of successful embryo transfer or natural pregnancy. Premenopausal women are often prescribed OCPs with a placebo week per month, leading to 12 weeks of estrogen deficiency annually. Oocyte donation remains the best option for achieving successful pregnancy in women with POI, with a 40% probability after one IVF cycle and 70-80% after four cycles.

Hb SKMC and an unprecedented γδβ-thalassemia: first report from Iraq

ABSTRACT Background Thalassemias are genetic disorders of globin chain synthesis. In Iraq, β-thalassemia is more prevalent than α-thalassemia. This study identifies two unpredicted globin gene mutations, a rare α-globin gene mutation (Hb SKMC) and a novel γδβ-thalassemia deletion. Methods Over 2 years, the Genetics unit at PAR hospital in Erbil, northern Iraq processed 137 β-thalassemia and 97 α-thalassemia genetic testing requests. Three symptomatic thalassemia cases with unreported genotypes were identified. Proband-1α and proband-2α had Hb H disease, while proband-1β had severe transfusion-dependent β-thalassemia (TDT). Molecular studies included multiplex PCR, reverse hybridization, multiplex ligation-dependent probe amplification (MLPA), and globin gene sequencing. Results The α-thalassemia probands exhibited moderate microcytic hypochromic anemia with irregular transfusions and splenomegaly. Hb H disease was confirmed by positive Hb H tests and high-performance liquid chromatography (HPLC). Molecular analysis revealed heterozygous –MED deletion in proband-1α and α2Poly-A2 mutation in proband-2α. Sequencing identified the Hb SKMC (HBA1:c.283_300+3dup) mutation in both probands. The β-thalassemia proband showed anemia and regular transfusions. Molecular studies detected the IVS1.110 G>A mutation and a novel γδβ-thalassemia deletion in compound heterozygous form. The maternal sample showed the IVS1.110 G>A mutation, and MLPA confirmed the γδβ-thalassemia deletion in the paternal sample. Conclusion These findings highlight the genetic diversity of thalassemias in the region and emphasize the importance of advanced molecular diagnostics in detecting rare mutations.

Long-term subclinical severe hyperCKemia associated with a rare VPS13A gene mutation in an Iranian patient: Case report.

The Article Abstract is not available.

Dysregulation of myelination-related genes in schizophrenia.

Schizophrenic individuals display disrupted myelination patterns, altered oligodendrocyte distribution, and abnormal oligodendrocyte morphology. Schizophrenia is linked with dysregulation of a variety of genes involved in oligodendrocyte function and myelin production. Single-nucleotide polymorphisms (SNPs) and rare mutations in myelination-related genes are observed in certain schizophrenic populations, representing potential genetic risk factors. Downregulation of myelination-related RNAs and proteins, particularly in frontal and limbic regions, is consistently associated with the disorder across multiple studies. These findings support the notion that disruptions in myelination may contribute to the cognitive and behavioral impairments experienced in schizophrenia, although further evidence of causation is needed.

Loss of Heterozygosity and Mutations in the RAS-ERK Pathway Genes in Tumor Cells of Various Loci in Multiple Myeloma.

Multiple myeloma (MM) is a disease characterized by spatiotemporal heterogeneity of tumor clones. Different genetic aberrations can be observed simultaneously in tumor cells from different loci, and as the disease progresses, new subclones may appear. The role of liquid biopsy, which is based on the analysis of tumor DNA circulating in the blood plasma, continues to be explored in MM. Here, we present an analysis of the STR profiles and mutation status of the KRAS, NRAS, and BRAF genes, evaluated in plasma free circulating tumor DNA (ctDNA), CD138+ bone marrow cells, and plasmacytomas. The prospective single-center study included 97 patients, with a median age of 55 years. Of these, 94 had newly diagnosed symptomatic MM, and three had primary plasma cell leukemia. It should be noted that if mutations were detected only in ctDNA, "non-classical" codons were more often affected. A variety of adverse laboratory and clinical factors have been associated with the detection of rare KRAS or NRAS gene mutations in bone marrow or ctDNA, suggesting that these mutations may be factors of an unfavorable prognosis for MM. Liquid biopsy studies provide undeniable fundamental information about tumor heterogeneity and clonal evolution in MM. Moreover, we focus on using liquid biopsy to identify new high-risk factors for MM.

Molecular analyses of MEFV gene mutation variants in Turkish population.

Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disease primarily affecting individuals of Turkish, Armenian, Arab, and non-Ashkenazi Jewish descent, caused by mutations in the MEFV gene. The aim of this study was to review the common genotype distributions of MEFV variants and mutations in the Turkish population and evaluate rare mutations. The study included 2984 patients who applied to Ankara University Ibni Sina Hospital Immunology Laboratory with clinical suspicion of FMF between 2004 and 2014. The data of patients from different regions of the country who were followed up in the immunology-rheumatology clinic with clinical suspicion and presumptive diagnosis of FMF were evaluated retrospectively. Patients were tested for all mutations in Exon 2 and Exon 10, including M694V, M680I, M694I, V726A, E148Q and R202Q. There were 2504 patients with FMF variant. According to genotyping, R202Q (n = 1567, 39.2%) was the most common mutation. The most common co-variant was the R202Q/M694V genotype (n = 507, 16.98%). Allele frequencies for MEFV mutations were as follows: R202Q (n = 1567, 39.2%), M694V (n = 1004, 25.1%), E148Q (n = 463, 11.5%), M680I (n = 354, 8.8%), V726A (n = 319, 7.9%), A744S (n = 51, 1.2%), R761H (N = 41, 1.0%), P706P (N = 25, 0.6%), E167D (N = 23, 0.5%), M694I (N = 23, 0.5%), and K695R (N = 20, 0.5%). This research revealed the prevalence of both common and rare MEFV gene mutations in Turkish FMF patients in various age groups. R202Q was the most prevalent mutation.

Hemochromatosis-How Not to Overlook and Properly Manage "Iron People"-A Review.

Hemochromatosis (HC) is the main genetic disorder of iron overload and is regarded as metal-related human toxicosis. HC may result from HFE and rare non-HFE gene mutations, causing hepcidin deficiency or, sporadically, hepcidin resistance. This review focuses on HFE-related HC. The illness presents a strong biochemical penetrance, but its prevalence is low. Unfortunately, the majority of patients with HC remain undiagnosed at their disease-curable stage. The main aim of HC management is to prevent iron overload in its early phase and remove excess iron from the body by phlebotomy in its late stage. Raising global awareness of HC among health staff, teaching them how not to overlook early HC manifestations, and paying attention to careful patient monitoring remain critical management strategies for preventing treatment delays, upgrading its efficacy, and improving patient prognosis.

Autoinflammatory Diseases: A Review.

Autoinflammatory disease (AID) is a vast spectrum of disorders characterized by recurrent attacks of sterile inflammation. Since the first cloning of the familial Mediterranean fever gene in 1997, there has been a rapid rate of discovery of new AIDs. As of 2022, there have been 485 inborn errors of immunity documented by the International Union of Immunological Societies, for which many display aspects of autoinflammation. The pathophysiology of AIDs is complex. Although many are caused by rare mutations in genes that govern innate immunity, others are polygenic, where disease expression is thought to be triggered by environmental factors in genetically predisposed hosts. AIDs range in prevalence from common entities like gout to ultrarare monogenic diseases. Whereas AIDs were initially studied in pediatric populations, it is now apparent that they can present in adulthood and even in the elderly. AIDs can be clinically challenging given their rarity, as well as the heterogeneity in presentation and underlying etiology. Although the care of AIDs can span medical disciplines, the rheumatologist often plays a central role given the inflammatory nature of these illnesses. In this review, we explore the current understanding of the pathophysiology of these complex conditions and propose a classification system for AIDs. We place an emphasis on AIDs that present to the adult rheumatologist and discuss important AIDs that can mimic more classic rheumatic diseases such as systemic lupus erythematosus and inflammatory arthritis. Finally, we offer an approach to the clinical assessment, diagnosis, and management of AIDs.

Rare VPS33B gene mutation combined with GP1BA mutation causes severe decrease in plasma VWF levels: a case report and literature review

A 28-year-old woman was found to have coagulation factor Ⅷ activity (FⅧ∶C) <1% and von Willebrand factor antigen (VWF∶Ag) <1% during routine prenatal examinations. No pathogenic variation was found in the exon region of the VWF gene using next-generation sequencing. The clinical presentation of this patient does not match the clinical characteristics of type Ⅲ hemophilia [von Willebrand disease (VWD) ]; therefore, third-generation sequencing technology was used to perform whole-genome sequencing on the patient and her family members. Multiple members of the patient's paternal family carried a heterozygous variant of VPS33B, c.869G>C. The family members carrying this variant all had varying degrees of reduced VWF levels (39% -56% ). Moreover, the proband was detected with the heterozygous variant c.1474dupA in GP1BA. The ACMG and Clinvar databases determined that this variation was associated with platelet-type pseudo VWD. The decrease in VWF levels caused by heterozygous variations in VPS33B in families is the first international report, and no previous studies have reported cases of severe decrease in plasma VWF levels caused by double heterozygous variations in VPS33B and GP1BA.

Routine antenatal molecular testing for α-thalassemia at a tertiary referral hospital in China: ten years of experience.

This study aimed to evaluate the efficacy of α-thalassemia gene testing as a part of an antenatal intervention program over a 10-year period. All patients underwent α-thalassemia gene testing, which included the analysis of three types of deletions and mutations. Rare α-thalassemia gene testing was performed using Sanger sequencing, multiplex ligation-dependent probe amplification, and sequencing techniques. Prenatal diagnosis was performed in high-risk couples using chorionic villus sampling or amniocentesis. From 2010 to 2019, among the 91,852 patients examined, α-thalassemia mutations were identified in 41.78% of patients. The most frequent α0 gene mutation was--SEA, followed by--THAI. Two rare α0-thalassemia gene mutations at --32.8 and --230, were also observed. A total of 2,235 high-risk couples were identified, of which 562 were affected, including three with the--SEA/--THAI genotype and one with the--SEA/--230 genotype. Additionally, prenatal diagnosis revealed four cases of fetal anemia and/or mild edema, along with two cases of severe fetal edema. Chromosome and gene chip results were normal. Thalassemia gene testing showed an αCSα/αCSα genotype in four patients with anemia and/or mild edema, while two patients with severe fetal edema had one--SEA/αCSα genotype and one--SEA/--GX genotype. Using the cut-off points of 74.6fL and 24.4pg as criteria for identifying α0-thalassemia carriers and HbH disease, the detection rate of missed diagnoses in high-risk couples is consistent with national guidelines for standards, potentially saving 10,217,700 ¥. Routine molecular testing for α-thalassemia in high-risk prenatal populations effectively prevented severe α-thalassemia births. Despite the high cost, the cutoff points proposed by this study suggest that implementing screening using a new parameter has the potential to reduce current expenses.

Afatinib Treatment for Advanced Mixed Non-small Cell Lung Cancer with CRISPLD2-NRG1 Fusion: A Case Report and Literature Review

Lung cancer is the most common malignant disease and the leading cause of cancer death in China. Non-small cell lung cancer (NSCLC) accounts for over 80% of all lung cancers, and the probability of NSCLC gene mutations is high, with a wide variety of types. With the development of next-generation sequencing (NGS) detection technology, more and more patients with rare fusion gene mutations are detected. Neuregulin 1 (NRG1) gene is a rare oncogenic driver that can lead to activation of human epidermal growth factor receptor 3 (Her3/ErbB3) mediated pathway, resulting in tumor formation. In this article, we reported a case of mixed NSCLC with CRISPLD2-NRG1 fusion detected by RNA-based NGS, who responsed to Afatinib well after 1 month of treatment, and magnetic resonance imaging (MRI) showed shrinkage of intracranial lesions. Meanwhile, we also compiled previously reported NSCLC patients with NRG1 rare gene fusion mutation, in order to provide effective references for clinical diagnosis and treatment. .

RFX6 regulates human intestinal patterning and function upstream of PDX1.

The gastrointestinal (GI) tract is complex and consists of multiple organs with unique functions. Rare gene variants can cause congenital malformations of the human GI tract, although the molecular basis of these has been poorly studied. We identified a patient with compound-heterozygous variants in RFX6 presenting with duodenal malrotation and atresia, implicating RFX6 in development of the proximal intestine. To identify how mutations in RFX6 impact intestinal patterning and function, we derived induced pluripotent stem cells from this patient to generate human intestinal organoids (HIOs). We identified that the duodenal HIOs and human tissues had mixed regional identity, with gastric and ileal features. CRISPR-mediated correction of RFX6 restored duodenal identity. We then used gain- and loss-of-function and transcriptomic approaches in HIOs and Xenopus embryos to identify that PDX1 is a downstream transcriptional target of RFX6 required for duodenal development. However, RFX6 had additional PDX1-independent transcriptional targets involving multiple components of signaling pathways that are required for establishing early regional identity in the GI tract. In summary, we have identified RFX6 as a key regulator in intestinal patterning that acts by regulating transcriptional and signaling pathways.

Study of the types of mutations of Thalassemia in Shanghai area

To analyze the mutations of globin genes among patients suspected for thalassemia from the Shanghai area. A total of 4 644 patients diagnosed at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine between June 2016 and December 2019 were selected as the study subjects. The patients were tested for common mutations associated with thalassemia gene by Gap-PCR and reverse dot blotting (RDB). Patients were suspected to harbor rare mutations based on the inconsistency between hematological phenotypes and results of common mutation detection, and were further analyzed by Gap-PCR and Sanger sequencing. Among the 4 644 patients, 2 194 (47.24%) were found to carry common thalassemia mutations, among which 701 (15.09%) were α-thalassemia, 1 448 (31.18%) were β-thalassemia, and 45 (0.97%) were both α- and β-thalassemia. Forty six samples were found to harbor rare mutations, which included 17 α-globin gene and 29 β-globin gene mutations. CD77(CCC>ACC) (HBA2: c.232C>A) of the α-globin gene, NG_000007.3: g.70567_71015del449, codon 102(-A) (HBB: c.308_308delA) and IVS-Ⅱ-636 (A>G) (HBB: c.316-215A>G) of the β-globin gene were previously unreported new types of globin gene mutations. Among the 4 644 patients, the detection rate for common thalassemia mutations was 47.24%, whilst 46 samples were detected with rare gene mutations. The type of gene mutation types were diverse in the Shanghai area. The study has provided more accurate results for genetic diagnosis and counseling.

Human Genetics of Ventricular Septal Defect.

Ventricular septal defects (VSDs) are recognized as one of the commonest congenital heart diseases (CHD), accounting for up to 40% of all cardiac malformations, and occur as isolated CHDs as well as together with other cardiac and extracardiac congenital malformations in individual patients and families. The genetic etiology of VSD is complex and extraordinarily heterogeneous. Chromosomal abnormalities such as aneuploidy and structural variations as well as rare point mutations in various genes have been reported to be associated with this cardiac defect. This includes both well-defined syndromes with known genetic cause (e.g., DiGeorge syndrome and Holt-Oram syndrome) and so far undefined syndromic forms characterized by unspecific symptoms. Mutations in genes encoding cardiac transcription factors (e.g., NKX2-5 and GATA4) and signaling molecules (e.g., CFC1) have been most frequently found in VSD cases. Moreover, new high-resolution methods such as comparative genomic hybridization enabled the discovery of a high number of different copynumber variations, leading to gain or loss of chromosomal regions often containing multiple genes, in patients with VSD. In this chapter, we will describe the broad genetic heterogeneity observed in VSD patients considering recent advances in this field.

Genetic Epidemiology of Primary Congenital Glaucoma in the World. Part I

To understand the current situation with the genetic epidemiology of primary congenital glaucoma (PCG) in the world, as well as to identify genotype-phenotype correlations, 87 publications were analyzed from the Pubmed and elibrary databases, mainly the latest 5 years. This publication presents the first part of the analysis, covering Arab and African countries, Turkey, the USA, Brazil, Australia and New Zealand. The second part of the review, which will be published in early 2024, will focus on data from East and South Asia, Western Europe and Russia. The highest incidence of PCG is typical for Arab countries, which is associated with the presence of a significant number of consanguineous marriages in these countries. In most countries, boys predominated among patients with PCG, and the process was often bilateral. In Australia female patients predominate. The PCG phenotype is more severe in patients with CYP1B1 mutations (early onset, bilateral involvement) than in patients without mutations, and in patients with consanguineous parents than in children from unrelated marriages. Among the genetic causes of PCG in different populations, the most common (from 30 to 86 % of cases) in Arab countries, Brazil and Turkey are mutations in the CYP1B1 gene. The spectrum of mutations varies depending on the region. In Australia and New Zealand, biallelic mutations were identified in the CYP1B1, CPAMD8 and COL18A1 genes, as well as heterozygous mutations in the TEK, FOXC1 and ANGPT1. Mutations in rare genes were also found in patients with PCG from Lebanon (ANGPT1 (p.K186N), Mauritania (NTF4 (c.601T&gt;G, p.Cys201Gly) and WDR36 (c.2078A&gt;G, p.Asn693Ser)). In the USA, the influence of the thrombospondin gene (THBS1) on the development of PCG is being studied. Based on the results of genetic and epidemiological studies, specific treatment, rehabilitation and preventive programs can be developed, which will determine the success of PCG therapy in children, preserving their visual functions.

Drosophila melanogaster as a Model Organism to Facilitate Rare Disease Diagnosis and Therapeutic Research

Cancer is one of the leading causes of death worldwide accounting for around 10 million deaths in 2020. Cancer is caused by abnormal growth of cells in any part of the body. Genetic causes of cancer can be due to mutations in the genes. Rare mutations in genes show rare types of tumors like Neurofibromatosis and Tuberous sclerosis. The study of model organisms has been pivotal in understanding the causes of various diseases. The studies involve a variety of different methods and out of them the WES (Whole Exome Sequencing) model of research is the most common. Herein lies the future of integrating human genomics with studies in model organisms. It is essential to maintain and expand the current Drosophila melanogaster databases this houses the genomic, molecular, and cell biological knowledge on the organism. This can be done by collaboration with the NIH. The understanding of the characteristics of cancer cells plays an important role in terms of how to go about with research tumor and normal host cell motility plays a multifaceted role in the metastasis of cancer by allowing the tumor to spread to distant organs, migrate to blood and lymphatic arteries, breach the basement membrane, and escape from the original tumor. The ability to migrate towards favourable environments is a fundamental and evolutionarily conserved cellular behaviour from unicellular organisms to humans. Both normal and cancer cells migrate using diverse modes including amoeboid, mesenchymal, epithelial, collective and individual. Simple model organisms also exhibit these diverse modes of motility and offer experimental advantages such as low cost, amenability to large-scale genetic and pharmacological screening and live imaging of cells interacting within their native environments. This article goes into detail about how drosophila can be used as a model organism to study various diseases such as Duchenne Muscular Dystrophy, Parkinsons disease, Prions diseases, Polyglutamine disorders, Huntington's disease, Machado-Josephs disease, Kennedy disease, Amyotrophic lateral sclerosis, Leigh Disease, Nieman-Pick Disease and a few rare tumours

Implications of combined NOD2 and other gene mutations in autoinflammatory diseases.

NOD-like receptors (NLRs) are intracellular sensors associated with systemic autoinflammatory diseases (SAIDs). We investigated the largest monocentric cohort of patients with adult-onset SAIDs for coinheritance of low frequency and rare mutations in NOD2 and other autoinflammatory genes. Sixty-three patients underwent molecular testing for SAID gene panels after extensive clinical workups. Whole exome sequencing data from the large Atherosclerosis Risk in Communities (ARIC) study of individuals of European-American ancestry were used as control. Of 63 patients, 44 (69.8%) were found to carry combined gene variants in NOD2 and another gene (Group 1), and 19 (30.2%) were carriers only for NOD2 variants (Group 2). The genetic variant combinations in SAID patients were digenic in 66% (NOD2/MEFV, NOD2/NLRP12, NOD2/NLRP3, and NOD2/TNFRSF1A) and oligogenic in 34% of cases. These variant combinations were either absent or significantly less frequent in the control population. By phenotype-genotype correlation, approximately 40% of patients met diagnostic criteria for a specific SAID, and 60% had mixed diagnoses. There were no statistically significant differences in clinical manifestations between the two patient groups except for chest pain. Due to overlapping phenotypes and mixed genotypes, we have suggested a new term, "Mixed NLR-associated Autoinflammatory Disease ", to describe this disease scenario. Gene variant combinations are significant in patients with SAIDs primarily presenting with mixed clinical phenotypes. Our data support the proposition that immunological disease expression is modified by genetic background and environmental exposure. We provide a preliminary framework in diagnosis, management, and interpretation of the clinical scenario.

Novel Finnish-enriched variants causing severe hypercholesterolemia and their clinical impact on coronary artery disease

Background and aimsSevere hypercholesterolemia (LDL-cholesterol ≥ 5 mmol/l) is a major risk factor for coronary artery disease (CAD). The etiology incudes both genetic and nongenetic factors, but persons carrying mutations in known hypercholesterolemia-associated genes are at significantly higher CAD risk than non-carriers. Yet, a significant proportion of mutation carriers remains undetected while the assessment of genetic candidate variants in clinical practice is challenging. MethodsTo address these challenges, we set out to test the utility of a practical approach to leverage data from a large reference cohort, the FinnGen Study encompassing 356,082 persons with extensive longitudinal health record information, to aid the clinical evaluation of single genetic candidate genes variants detected by exome sequence analysis in a target population of 351 persons with severe hypercholesterolemia. ResultsWe identified 23 rare missense mutations in known hypercholesterolemia genes, 3 of which were previously described mutations (LDLR Pro309Lysfs, LDLR Arg595Gln and APOB Arg3527Gln). Subsequent in silico and clinical assessment of the remaining 20 variants pinpointed two likely hypercholesterolemia-associated variants in LDLR (Arg574Leu and Glu626Lys) and one in LDLRAP1 (Arg151Trp). Heterozygous carriers of the novel LDLR and LDLRAP1 variants received statin treatment more often than non-carriers (OR 2.1, p = 1.8e-6 and OR 1.4, p = 0.001) and untreated carriers had higher risk for ischemic heart disease (OR 2.0, p = 0.03 and OR 1.8, p = 0.008). ConclusionsOur data elucidate the wide spectrum of genetic variants impacting hypercholesterolemia and demonstrate the utility of a large reference population to assess the heterogeneous impact of candidate gene variants on cardiovascular disease risk.

Genetics of bronchopulmonary dysplasia: An update

Bronchopulmonary dysplasia (BPD) is a multi-factorial disease that results from multiple clinical factors, including lung immaturity, mechanical ventilation, oxidative stress, pulmonary congestion due to increasing cardiac blood shunting, nutritional and immunological factors. Twin studies have indicated that susceptibility to BPD can be strongly inherited in some settings. Studies have reported associations between common genetic variants and BPD in preterm infants. Recent genomic studies have highlighted a potential role for molecular pathways involved in inflammation and lung development in affected infants. Rare mutations in genes encoding the lipid transporter ATP-binding cassette, sub-family A, member 3 (ABCA3 gene) which is involved in surfactant synthesis in alveolar type II cells, as well as surfactant protein B (SFTPB) and C (SFTPC) can also result in severe form of neonatal-onset interstitial lung diseases and may also potentially affect the course of BPD. This chapter summarizes the current state of knowledge on the genetics of BPD.