NPJ Genomic Medicine最新文献

Muscle phosphorylase kinase deficiency results from X-linked pathogenic variants in PHKA1, leading to glycogen storage disease (GSD) type IXα1 (also known as GSD IXd). As part of an international collaboration, we describe 14 previously unreported cases (12 males, 2 females; ClinicalTrials.gov NCT04454216, registered 2020-07-01). We compared our cohort to 18 cases previously reported and to an additional 16 cases identified through the National Institutes of Health All of Us Research Program. The clinical presentations highlight the predominance of myopathic symptoms on exertion and emphasize the variability in age of onset. Examination of muscle biopsies revealed glycogen accumulation and an increase in lipid droplets indicative of mitochondrial dysfunction and mitophagy. We encourage clinicians to maintain a high level of suspicion even in the setting of normal blood creatine kinase levels. Comprehensive longitudinal natural history studies remain necessary to improve disease detection, inform management guidelines, and provide a foundation for therapeutic development.

The germline genetic susceptibility to adult glioblastoma remains unclear. With the option of broad molecular testing, it is crucial that clinicians are aware of the a priori probability of finding germline predisposition in glioblastoma patients. Here, we studied the genetic predisposition to adult glioblastoma using paired tumor-normal WGS data in an unselected, average cohort of 92 glioma WHO grade 4 patients. In 10 patients (11%), 12 Pathogenic Germline Variants (PGVs) were found in genes strongly associated with familial glioblastoma (MSH6 (3x), PMS2 (5x), MSH2, NF1, BRCA1) or medulloblastoma (SUFU). In six of these patients (60%), causality was supported by a second (somatic) event and/or a matching genome-wide mutational signature. Thus, germline predisposition does play a role in the development of adult glioblastoma, with mismatch repair deficiency being the main mechanism. Our results also highlight the benefits of tumor-normal WGS for glioblastoma patients and their families, beyond identifying actionable mutations for therapy.

This study aimed to evaluate the feasibility of whole-genome sequencing (WGS) combined with computational tools for spinal muscular atrophy (SMA) carrier screening and disease diagnosis in Taiwan. WGS data from 1492 Taiwan Biobank participants and two patients with SMA were analysed to determine the SMN1 and SMN2 copy numbers using Illumina DRAGEN SMN Caller and validated by multiplex ligation-dependent probe amplification (MLPA). Among 1480 samples analysed, 23 SMA carriers were identified, yielding a carrier frequency of 1.55%. MLPA confirmed the accuracy of SMN1 and SMN2 copy number results detected using WGS. Both patients with SMA presented compound heterozygous variants with one SMN1 copy loss and the other SMN1 variant, specifically SMN1,c.815A>G, and SMN1,c.81+2_81+3delTG, respectively. Taken together, combining WGS with advanced bioinformatics tools is a feasible and promising approach for SMA carrier screening and disease diagnosis.

Missense and loss-of-function variants in SPECC1L are associated with Teebi Hypertelorism Syndrome 1 (TBHS1). Here, we report a novel SPECC1L intragenic deletion encompassing exon 3, which contains the canonical translation start site, in two related individuals with craniofacial features consistent with TBHS1. We use functional overexpression assays to demonstrate that this deletion leads to alternative start codon usage and protein truncation. This is the first report of a SPECC1L intragenic deletion associated with TBHS1. Our findings suggest that deletion of the canonical N-terminal disordered region of SPECC1L contributes to craniofacial anomalies, warranting further investigation into its role in neural crest development.

Oro-Facial-Digital Syndrome (OFDS) and Joubert syndrome are ciliary disorders. Fifteen individuals of consanguineous Bedouin kindred presented with global developmental delay with no speech, and a clear OFDS phenotype, combined with Joubert syndrome, with MRI showing hypoplastic corpus callosum and molar tooth sign. Renal and liver function tests and ultrasound were unremarkable. Within a 0.5 Mb disease-associated locus (LOD score 6.2), whole genome sequencing identified a single variant: CEP83 NG_051825.2:g.5774dupG, (NM_016122.3):c.-278dupG. Patient fibroblasts showed aberrantly long cilia, and alternative splicing of CEP83 5'UTR, skipping most of exon 1 of the canonical transcript, and frameshift, abrogating CEP83 mRNA and protein expression. CEP83 acts in primary cilium assembly. CEP83 biallelic missense or in-frame deletions, with presumed residual function, were previously associated with early-onset nephronophthisis culminating in end-stage renal disease. We now demonstrate that a biallelic complete loss-of-function CEP83 variant culminates in elongated primary cilia, causing OFDS with Joubert-like features without evident renal involvement.

Adolescent idiopathic scoliosis (AIS) is a complex genetic disorder. This study used whole-genome sequencing (WGS) to investigate the genetic basis of AIS in 119 patients from 103 families. Our WGS analysis identified known pathogenic or protein-truncating variants in 15 probands, and other strong or moderate candidate variants in 69 additional patients. We found both coding and non-coding mutations, including structural variants. Candidate genes included known AIS genes (e.g., COL11A2, FBN1) and genes linked to other musculoskeletal disorders with scoliosis (e.g., RYR1). Association analysis confirmed four known AIS single-nucleotide polymorphisms in our cohort. Gene set enrichment analysis revealed four gene clusters related to skeletal muscle contraction, extracellular matrix, and gene expression regulation. This WGS-based approach identified clinically relevant genetic variations and biological pathways in AIS patients, offering valuable insights into its complex development.

Many congenital anomaly patients lack genetic diagnoses because there are many disease genes as yet to be discovered. We applied a gene burden test incorporating de novo predicted-loss-of-function (pLoF) and likely damaging missense variants together with inherited pLoF variants to a collection of congenital heart defect (CHD) and orofacial cleft (OFC) parent-offspring trio cohorts (n = 3835 and 1844, respectively). We identified 17 novel candidate CHD genes and 8 novel candidate OFC genes, of which many were known developmental disorder genes. TFs were enriched among the significant genes; 14 and 8 transcription factor (TF) genes showed significant variant burden for CHD and OFC, respectively. In total, 30 affected children had a de novo missense variant in a DNA binding domain of a known CHD, OFC, and other developmental disorder TF genes. Our results suggest candidate pathogenic variants in CHD and OFC and their potentially pleiotropic effects in other developmental disorders.

Common genetic variation detected by genome-wide association studies (GWAS) partially explains variability in the spectrum of cardiac phenotypes. In this work, we explore genetic correlations among 58 cardiac-related traits/diseases, detecting novel ones. We subsequently employ multi-trait analysis of GWAS (MTAG), which meta-analyzes genetically correlated traits, to improve genomic loci discovery and prediction in atrial fibrillation (AF), coronary artery disease (CAD), and heart failure (HF). We identify 19 novel loci specific for AF, 131 for CAD, and 141 for HF. Polygenic scores (PGS) in 15,177 Canadian individuals show similar results when PGS are derived from conventional GWAS versus MTAG summary statistics, although MTAG-PGS improve prediction and discrimination of CAD in females [∆R² 1.735% (95% Confidence Interval (CI): 0.609-2.856); Net reclassification index 0.208 (95%CI: 0.139-0.277)]. This work describes new relevant genetic correlations among cardiac-related traits/diseases and supports MTAG to improve loci discovery in common cardiovascular diseases and potentially improve the prediction of CAD in females.

Gamma-butyrobetaine hydroxylase (BBOX1) catalyses the last step of carnitine biosynthesis, converting γ-butyrobetaine (γ-BB) into L-carnitine. Here we show, for the first time, that biallelic variants in BBOX1 are associated with decreased levels of L-carnitine and increased plasma levels of γ-BB in three patients from two unrelated families presenting with myopathic, neurodevelopmental, and late-onset psychiatric manifestations. Using a knockout C. elegans model of BBOX1 homolog, gbh-1, and strains harboring patient-derived variants (gbh-1(D72G) for p.Asp59Gly, gbh-1(G283R) for p.Gly263Arg, and gbh-1(G247Vfs6) for p.Gly227Valfs*6), we show very low L-carnitine levels and significantly elevated γ-BB in c.675delA and c.787G>A mutants, and moderately elevated γ-BB in c.176A>G. Furthermore, we observed a lethal embryonic phenotype for the gbh-1 loss-of-function strains, which was rescued upon L-carnitine supplementation. Our study provides novel insights into the clinical and biochemical consequences of BBOX1-related L-carnitine biosynthesis deficiency and establishes C. elegans as a model to study the effects of BBOX1 deficiency.