Publications by authors named "Michael A Simpson"

Article Synopsis
  • The study investigates the complex relationship between immune-mediated diseases (IMIDs), like psoriasis, and cardiovascular diseases (CVDs), such as coronary artery disease (CAD) and stroke, focusing on genetic factors.
  • It employs Mendelian randomization to analyze data from large genome-wide association studies (GWAS) to establish potential causative links between psoriasis and these cardiovascular conditions.
  • The analysis encompasses nearly 3.4 million individuals, providing insights into how genetic predictors of CAD and stroke may influence the risk of developing psoriasis and nine other IMIDs.
View Article and Find Full Text PDF

Importance: Frontal fibrosing alopecia (FFA) is an increasingly prevalent form of follicular lichen planus, causing irreversible hair loss predominantly in postmenopausal individuals. An earlier genome-wide meta-analysis of female FFA identified risk loci in genes implicated in self-antigen presentation and T-cell homeostasis, including HLA-B*07:02, ST3GAL1, and SEMA4B. However, CYP1B1, which is important for hormone metabolism, was also implicated with the substitution of serine for asparagine at position 453 (c.

View Article and Find Full Text PDF

Psoriasis is a common, debilitating immune-mediated skin disease. Genetic studies have identified biological mechanisms of psoriasis risk, including those targeted by effective therapies. However, the genetic liability to psoriasis is not fully explained by variation at robustly identified risk loci.

View Article and Find Full Text PDF
Article Synopsis
  • Targeted biologic therapies, such as adalimumab, can provoke the creation of antidrug antibodies (ADA), leading to treatment failures in immune-mediated diseases.
  • This study focused on identifying genetic variations that make certain patients more likely to develop ADA against adalimumab, particularly in psoriasis patients on their first treatment course.
  • The researchers found specific genetic markers in the major histocompatibility complex (MHC) that correlate with resistance to ADA development, suggesting that these markers play a key role in the effectiveness of biologic therapies.
View Article and Find Full Text PDF
Article Synopsis
  • Embryonic development relies on precise DNA processes, and mutations in repair genes can cause neurodevelopmental disorders with symptoms like microcephaly and short stature.
  • Researchers identified genetic variants in SLF2 and SMC5 from the RAD18-SLF1/2-SMC5/6 pathway in patients with developmental issues, including abnormal chromosomes and anemia.
  • The new disorder, named Atelís Syndrome, demonstrates heightened replication stress and difficulties with specific DNA structures, emphasizing the crucial role of the SLF2-SMC5/6 pathway in preserving genome stability.
View Article and Find Full Text PDF

Background: Despite advances in next generation sequencing technologies, the identification of variants of uncertain significance (VUS) can often hinder definitive diagnosis in patients with complex neurodevelopmental disorders.

Objective: The objective of this study was to identify and characterize the underlying cause of disease in a family with two children with severe developmental delay associated with generalized dystonia and episodic status dystonicus, chorea, epilepsy, and cataracts.

Methods: Candidate genes identified by autozygosity mapping and whole-exome sequencing were characterized using cellular and vertebrate model systems.

View Article and Find Full Text PDF

Objectives: Psoriatic arthritis (PsA) has a strong genetic component, and the identification of genetic risk factors could help identify the ~30% of psoriasis patients at high risk of developing PsA. Our objectives were to identify genetic risk factors and pathways that differentiate PsA from cutaneous-only psoriasis (PsC) and to evaluate the performance of PsA risk prediction models.

Methods: Genome-wide meta-analyses were conducted separately for 5,065 patients with PsA and 21,286 healthy controls and separately for 4,340 patients with PsA and 6,431 patients with PsC.

View Article and Find Full Text PDF
Article Synopsis
  • * A genome-wide association study (GWAS) examined over 20,000 individuals and discovered 29 new genetic locations linked to acne, alongside confirming 14 previously recognized risk factors, raising the total to 46.
  • * The study also found connections between acne genetics and other health issues, such as hormone levels and psychiatric traits, and created a polygenic risk score that accounts for about 5.6% of acne risk in another group.
View Article and Find Full Text PDF

Background: Sudden cardiac arrest (SCA) and sudden unexplained death (SUD) are feared sequelae of many genetic heart diseases. In rare circumstances, pathogenic variants in cardiomyopathy-susceptibility genes may result in electrical instability leading to SCA/SUD before any structural manifestations of underlying cardiomyopathy are evident.

Methods: Collectively, 38 unexplained SCA survivors (21 males; mean age at SCA 26.

View Article and Find Full Text PDF

In view of the growth of clinical risk prediction models using genetic data, there is an increasing need for studies that use appropriate methods to select the optimum number of features from a large number of genetic variants with a high degree of redundancy between features due to linkage disequilibrium (LD). Filter feature selection methods based on information theoretic criteria, are well suited to this challenge and will identify a subset of the original variables that should result in more accurate prediction. However, data collected from cohort studies are often high-dimensional genetic data with potential confounders presenting challenges to feature selection and risk prediction machine learning models.

View Article and Find Full Text PDF

Background Sudden cardiac arrest is the leading mode of death in the United States. Epilepsy affects 1% of Americans; yet epidemiological data show a prevalence of 4% in cases of sudden cardiac arrest. Sudden unexpected death in epilepsy (SUDEP) may share features with sudden cardiac arrest.

View Article and Find Full Text PDF

The identification of robust endotypes-disease subgroups of clinical relevance-is fundamental to stratified medicine. We hypothesized that HLA-C∗06:02 status, the major genetic determinant of psoriasis, defines a psoriasis endotype of clinical relevance. Using two United Kingdom-based cross-sectional datasets-an observational severe-psoriasis study (Biomarkers of Systemic Treatment Outcomes in Psoriasis; n = 3,767) and a large population-based bioresource (UK Biobank, including n = 5,519 individuals with psoriasis)-we compared demographic, environmental, and clinical variables of interest in HLA-C∗06:02-positive (one or two copies of the HLA-C∗06:02 allele) with those in HLA-C∗06:02‒negative (no copies) individuals of European ancestry.

View Article and Find Full Text PDF

Background: The U.K. 100,000 Genomes Project is in the process of investigating the role of genome sequencing in patients with undiagnosed rare diseases after usual care and the alignment of this research with health care implementation in the U.

View Article and Find Full Text PDF

Sterol-C4-methyl oxidase (SC4MOL) deficiency was recently described as an autosomal recessive cholesterol biosynthesis disorder caused by mutations in the MSMO1 (sometimes also referred to as SC4MOL) gene. To date, 5 patients from 4 unrelated families with SC4MOL deficiency have been reported. Diagnosis can be challenging as the biochemical accumulation of methylsterols can affect global development and cause skin and ocular pathology.

View Article and Find Full Text PDF

Objective: We aimed to describe the extent of neurodevelopmental impairments and identify the genetic etiologies in a large cohort of patients with epilepsy with myoclonic atonic seizures (MAE).

Methods: We deeply phenotyped MAE patients for epilepsy features, intellectual disability, autism spectrum disorder, and attention-deficit/hyperactivity disorder using standardized neuropsychological instruments. We performed exome analysis (whole exome sequencing) filtered on epilepsy and neuropsychiatric gene sets to identify genetic etiologies.

View Article and Find Full Text PDF

Psoriasis is a common inflammatory skin disease caused by the interplay between multiple genetic and environmental risk factors. This review summarises recent progress in elucidating the genetic basis of psoriasis, particularly through large genome-wide association studies. We illustrate the power of genetic analyses for disease stratification.

View Article and Find Full Text PDF

Dermatofibromas are common benign skin lesions, the etiology of which is poorly understood. We identified two unrelated pedigrees in which there was autosomal dominant transmission of multiple dermatofibromas. Whole exome sequencing revealed a rare shared heterozygous missense variant in the F13A1 gene encoding factor XIII subunit A (FXIII-A), a transglutaminase involved in hemostasis, wound healing, tumor growth, and apoptosis.

View Article and Find Full Text PDF

Background: Invasive lobular breast cancer (ILC) accounts for approximately 15% of invasive breast carcinomas and is commonly associated with lobular carcinoma (LCIS). Both have been shown to have higher familial risks than the more common ductal cancers. However, there are little data on the prevalence of the known high and moderate penetrance breast cancer predisposition genes in ILC.

View Article and Find Full Text PDF

Mitochondrial dysfunction has been implicated in the etiology of monogenic Parkinson's disease (PD). Yet the role that mitochondrial processes play in the most common form of the disease; sporadic PD, is yet to be fully established. Here, we comprehensively assessed the role of mitochondrial function-associated genes in sporadic PD by leveraging improvements in the scale and analysis of PD GWAS data with recent advances in our understanding of the genetics of mitochondrial disease.

View Article and Find Full Text PDF

Introduction: Ductal carcinoma in situ (DCIS) is a non-obligate precursor of invasive ductal breast cancer, and approximately 20% of screen-detected tumours are pure DCIS. Most risk factors for breast cancer have similar associations with DCIS and IDC; however, there is limited data on the prevalence of the known high and moderate penetrance breast cancer predisposition genes in DCIS and which women with DCIS should be referred for genetic screening. The aim of this study was to assess the frequency of germline variants in BRCA2, BRCA1, CHEK2, PALB2 and TP53 in DCIS in women aged less than 50 years of age.

View Article and Find Full Text PDF