ObjectivesMyotonic dystrophy type 1 (DM1) is the most common muscular dystrophy in adults, yet there are currently no disease-modifying treatments. Disrupted miRNA expressions may lead to dysregulation of target mRNAs and dysfunction involved in DM1 pathogenic mechanism.MethodsWe used microarray platforms to examine the miRNA/mRNA expression profiles in skeletal muscle biopsies derived from DM1 patients and matched controls. Bioinformatics analysis and dual-luciferase reporter assay were conducted to provide insight into miRNA-mRNA regulatory networks altered in DM1.ResultsTwenty-three differentially expressed miRNAs and 135 differentially expressed genes were identified. qPCR confirmed that miR-3201, myogenic factor 5 (MYF5), myogenic differentiation 1 (MYOD1), CUGBP, Elav-like family member 1 (CELF1), and CELF2 were significantly up-regulated, while miR-196a, miR-200c, and miR-146a were significantly down-regulated. Enriched functions and pathways such as multicellular organismal development, RNA splicing, cell differentiation, and spliceosome are relevant to DM1. The miRNA-mRNA interaction network revealed that miR-182, miR-30c-2, and miR-200c were the critical nodes that potentially interacted with hub genes. Luciferase reporter assay confirmed the direct interaction between miR-196a and CELF2.ConclusionThose results implied that the observed miRNA/mRNA dysregulation could contribute to specific functions and pathways related to DM1 pathogenesis, highlighting the dysfunction of miR-196a and CELF2.
Autosomal recessive spinocerebellar ataxias (SCARs) are a heterogeneous group of neurodegenerative disorders. VPS13D gene is currently the only gene associated with autosomal recessive spinocerebellar ataxia type 4 (SCAR4), also known as VPS13D dyskinesia. SCAR4 is a rare inherited disease, with only 34 reported cases reported worldwide. In this study, we reported three independent SCAR4 cases with adolescent onsets caused by five novel variants of the VPS13D gene. Each patient carried one frameshift and one missense variant: Patient 1 with c.10474del and c.9734C > A (p.Leu3492Tyrfs*43 and p.Thr3245Asn), Patient 2 with c.6094_6107delGTTCTCTTGATCCC and c.9734C > A (p.Val2032Argfs*7 and p.Thr3245Asn), and Patient 3 with c.11954_11963del and c.9833 T > G (p.Phe3985Serfs*10 and p.Ile3278Ser). Two of the three patients shared nystagmus with an identical variant c.9734C > A. Magnetic resonance imaging indicated thoracic spinal atrophy in all three patients and corpus callosum atrophy in one patient, along with other typical manifestations of white matter degradation, cerebral atrophy, and cerebellar atrophy. These findings expanded the genetic, clinical, and neuroimaging spectrum of SCAR4, and provided new insights into the genetic counseling, molecular mechanisms, and differential diagnosis of the disease.
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease. To identify additional genetic factors, we analyzed exome sequences in a large cohort of Chinese ALS patients and found a homozygous variant (p.L700P) in PCDHA9 in three unrelated patients. We generated Pcdhα9 mutant mice harboring either orthologous point mutation or deletion mutation. These mice develop progressive spinal motor loss, muscle atrophy, and structural/functional abnormalities of the neuromuscular junction, leading to paralysis and early lethality. TDP-43 pathology is detected in the spinal motor neurons of aged mutant mice. Mechanistically, we demonstrate that Pcdha9 mutation causes aberrant activation of FAK and PYK2 in aging spinal cord, and dramatically reduced NKA-α1 expression in motor neurons. Our single nucleus multi-omics analysis reveals disturbed signaling involved in cell adhesion, ion transport, synapse organization, and neuronal survival in aged mutant mice. Together, our results present PCDHA9 as a potential ALS gene and provide insights into its pathogenesis.
LINS1 is the human homolog of the Drosophila segment polarity gene that encodes an essential regulator of the wingless/Wnt signaling. By 2011, only seven pedigrees (16 patients) with eight causative variants in LINS1 gene have been reported. These cases mainly presented with infancy-/child-onset neurodevelopmental disorders, facial dysmorphia, and other clinical features, and a wide spectrum of clinically distinct phenotypes were also manifested. In our study, two brothers in a family were admitted and diagnosed with child-onset movement disorders, slight intellectual disability, psychological symptoms, eye problems, urinary and bowel dysfunction, mitral value prolapse, and Q-T prolongation. By exome sequencing, we identified a nonsense homozygous pathogenic variant (LINS1: c.274C > T (p.Q92X)), which had been reported in a case diagnosed with intellectual disability and psychiatric disorders (such as schizophrenia and anxiety). Compared with this case, the clinical features of our cases were distinct. In particular, our cases displayed unusual features of heart and blood system. Furthermore, the genotype-phenotype relationship analysis suggested that distinct phenotypes presented in cases carrying variants in different domains of the LINS1 gene. In conclusions, our findings suggest the high clinical variations in the LINS1 variants-related disorders. Moreover, the Q92X might be a recurrent variant in Hans of Southern China.
Clematis tomentella 2001 (Ranunculaceae) is a typical drought-tolerant sand-fixing plant in desert ecosystem in northwest China. To elucidate the phylogenetic status of C. tomentella and its related species, we determined the complete chloroplast (cp) genome and analyzed their interspecific relationships. The result showed that the cp genome of C. tomentella was 159 816 bp in length, including two inverted repeats of 31 045 bp, a large single copy region of 79 535 bp, and a small single copy region of 18 191 bp. 136 genes were annotated across the whole cp genome, including 92 protein-coding genes, 8 rRNA genes, and 36 tRNA genes, as well as the GC content accounted for 38
BACKGROUND AND PURPOSE:Multiple system atrophy (MSA) is a progressive, adult-onset neurodegenerative disorder clinically characterized by combinations of autonomic failure, parkinsonism, cerebellar ataxia and pyramidal signs. Although a few genetic factors have been reported to contribute to the disease, its mutational profiles have not been systemically studied. METHODS:To address the genetic profiles of clinically diagnosed MSA patients, exome sequencing and triplet repeat detection was conducted in 205 MSA patients, including one familial case. The pathogenicity of variants was determined according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology guidelines. RESULTS:In the familial patient, a novel heterozygous COQ2 pathogenic variant (p.Ala351Thr) was identified in the MSA pedigree. In the sporadic patients, 29 pathogenic variants were revealed in 21 genes, and the PARK7 p.Ala104Thr variant was significantly associated with MSA (p = 0.0018). Moreover, burden tests demonstrated that the pathogenic variants were enriched in cerebellar ataxia-related genes in patients. Furthermore, repeat expansion analyses revealed that two patients carried the pathogenic CAG repeat expansion in the CACNA1A gene (SCA6), one patient carried the (ACAGG)exp/(ACAGG)exp expansion in RFC1 and one carried the GAA-pure expansion in FGF14 gene. CONCLUSION:In conclusion, a novel COQ2 pathogenic variant was identified in a familial MSA patient, and repeat expansions in CACNA1A, RFC1 and FGF14 gene were detected in four sporadic patients. Moreover, a PARK7 variant and the burden of pathogenic variants in cerebellar ataxia-related genes were associated with MSA.
Brain iron accumulation disorders (BIADs) are a group of diseases characterized by iron overload in deep gray matter nuclei, which is a common feature of neurodegenerative diseases. Although genetic factors have been reported to be one of the etiologies, much more details about the genetic background and molecular mechanism of BIADs remain unclear. This study aimed to illustrate the genetic characteristics of BIADs and clarify their molecular mechanisms. A total of 84 patients with BIADs were recruited from April 2018 to October 2022 at Xuanwu Hospital. Clinical characteristics including family history, consanguineous marriage history, and age at onset (AAO) were collected and assessed by two senior neurologists. Neuroimaging data were conducted for all the patients, including cranial magnetic resonance imaging (MRI) and susceptibility-weighted imaging (SWI). Whole-exome sequencing (WES) and capillary electrophoresis for detecting sequence mutation and trinucleotide repeat expansion, respectively, were conducted on all patients and part of their parents (whose samples were available). Variant pathogenicity was assessed according to the American College of Medical Genetics and Association for Molecular Pathology (ACMG/AMP). The NBIA and NBIA-like genes with mutations were included for bioinformatic analysis, using Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genome (KEGG). GO annotation and KEGG pathway analysis were performed on Metascape platform. In the 84 patients, 30 (35.7%) were found to carry mutations, among which 20 carried non-dynamic mutations (missense, stop-gained, frameshift, inframe, and exonic deletion) and 10 carried repeat expansion mutations. Compared with sporadic cases, familial cases had more genetic variants (non-dynamic mutation: P =0.025, dynamic mutation: P =0.003). AAO was 27.85±10.42 years in cases with non-dynamic mutations, which was significantly younger than those without mutations (43.13±17.17, t =3.724, P <0.001) and those with repeated expansions (45.40±8.90, t =4.550, P <0.001). Bioinformatic analysis suggested that genes in lipid metabolism, autophagy, mitochondria regulation, and ferroptosis pathways are more likely to be involved in the pathogenesis of BIADs. This study broadens the genetic spectrum of BIADs and has important implications in genetic counselling and clinical diagnosis. Patients diagnosed as BIADs with early AAO and family history are more likely to carry mutations. Bioinformatic analysis provides new insights into the molecular pathogenesis of BIADs, which may shed lights on the therapeutic strategy for neurodegenerative diseases.
BackgroundEpilepsy (EP) is a common neurological disease in which 70-80% are thought to have a genetic cause. In patients with epilepsy, neurodevelopmental delay (NDD) was prevalent. Next generation of sequencing has been widely used in diagnosing EP/NDD. However, the diagnostic yield remains to be 40%-50%. Many reanalysis pipelines and software have been developed for automated reanalysis and decision making for the diseases. Nevertheless, it is a highly challenging task for smaller genetic centers or a routine pediatric practice. To address the clinical and genetic "diagnostic odyssey," we organized a Multidisciplinary Molecular Consultation (MMC) team for molecular consultation for 202 children with EP/NDD patients referred by lower level hospitals. MethodsAll the patients had undergone an aligned and sequential consultations and discussions by a "triple reanalysis" procedure by clinical, genetic specialists, and researchers. ResultsAmong the 202 cases for MMC, we totally identified 47 cases (23%) harboring causative variants in 24 genes and 15 chromosomal regions after the MMC. In the 15 cases with positive CNVs, 3 cases harbor the deletions or duplications in 16p11.2, and 2 cases for 1p36. The bioinformatical reanalysis revealed 47 positive cases, in which 12 (26%) were reported to be negative, VUS or incorrectly positive in pre-MMC reports. Additionally, among 87 cases with negative cases, 4 (5%) were reported to be positive in pre-MMC reports. ConclusionWe established a workflow allowing for a "one-stop" collaborative assessments by experts of multiple fields and helps for correct the diagnosis of cases with falsenegative and -positive and VUS genetic reports and may have significant influences for intervention, prevention and genetic counseling of pediatric epilepsy and neurodevelopmental disorders.
Abstract Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease. To identify additional genetic contributors to ALS, we analyzed exome sequences in a large cohort of Chinese ALS patients. We found a homozygous variant (p.L700P) in PCDHA9 in three unrelated patients but not in publicly available genomic databases. We generated Pcdhα9 mutant mice harboring either orthologous point mutation or deletion mutation. These mice developed progressive spinal motor loss, muscle atrophy, and structural/functional abnormalities of the neuromuscular junction, leading to paralysis and early lethality. Importantly, TDP-43 pathology was observed in the ventral spinal motor neurons of aged point mutant mice. Mechanistically, we demonstrate that Pcdha9 mutation causes aberrant activation of FAK and PYK2 in the aged spinal cord. Furthermore, we uncovered a novel PCDHA9-interacting protein, Na+/K+ ATPase-α1, and its dramatically reduced expression in mutant motor neurons. Accordingly, single nucleus multi-omics analysis revealed disturbed networks or signaling involved in cell/cell-cell adhesion, ion transport, synapse organization, and neuronal survival in aged mutant mice. Together, our results present PCDHA9 as a new candidate ALS gene and provide insights into its pathogenesis.
Astragalus melilotoides Pall. 1776 is a perennial leguminous forage, widely distributed in northern China, with cold, drought and disease resistance characteristics. Here, we determined the complete chloroplast (cp) genome sequence of A. melilotoides. It was 123,827 bp in length and 36.97% GC content with IR loss. The cp genome contained 110 complete genes, including 76 protein-coding genes, 30 tRNA genes, and four rRNA genes. A maximum likelihood (ML) phylogenetic tree revealed that A. melilotoides was related to A. americanus, A. gummifer, A. mongholicus, A. nakaianus, A. mongholicus var. nakaianus, and A. membranaceus var. membranaceus. The cp genome analysis of A. melilotoides will provide a reference for the phylogenetic study of Astragalus in the future.
Background: Accurate diagnosis of Parkinson’s disease (PD) is challenging due to its diverse manifestations. Machine learning (ML) algorithms can improve diagnostic precision, but their generalizability across medical centers in China is underexplored. Objective: To assess the accuracy of an ML algorithm for PD diagnosis, trained and tested on data from different medical centers in China. Methods: A total of 1656 participants were included, with 1028 from Beijing (training set) and 628 from Fuzhou (external validation set). Models were trained using the least absolute shrinkage and selection operator–logistic regression (LASSO-LR), decision tree (DT), random forest (RF), eXtreme gradient boosting (XGboost), support vector machine (SVM), and k-nearest neighbor (KNN) techniques. Hyperparameters were optimized using five-fold cross-validation and grid search techniques. Model performance was evaluated using the area under the curve (AUC) of the receiver operating characteristic (ROC) curve, accuracy, sensitivity (recall), specificity, precision, and F1 score. Variable importance was assessed for all models. Results: SVM demonstrated the best differentiation between healthy controls (HCs) and PD patients (AUC: 0.928, 95% CI: 0.908–0.947; accuracy: 0.844, 95% CI: 0.814–0.871; sensitivity: 0.826, 95% CI: 0.786–0.866; specificity: 0.861, 95% CI: 0.820–0.898; precision: 0.849, 95% CI: 0.807–0.891; F1 score: 0.837, 95% CI: 0.803–0.868) in the validation set. Constipation, olfactory decline, and daytime somnolence significantly influenced predictability. Conclusion: We identified multiple pivotal variables and SVM as a precise and clinician-friendly ML algorithm for prediction of PD in Chinese patients.
Objective: In 2021, the Clinical Genome Resource (ClinGen) amyotrophic lateral sclerosis (ALS) spectrum disorders Gene Curation Expert Panel (GCEP) was established to evaluate the strength of evidence for genes previously reported to be associated with ALS. Through this endeavor, we will provide standardized guidance to laboratories on which genes should be included in clinical genetic testing panels for ALS. In this manuscript, we aimed to assess the heterogeneity in the current global landscape of clinical genetic testing for ALS. Methods: We reviewed the National Institutes of Health (NIH) Genetic Testing Registry (GTR) and members of the ALS GCEP to source frequently used testing panels and compare the genes included on the tests. Results: 14 clinical panels specific to ALS from 14 laboratories covered 4 to 54 genes. All panels report on ANG, SOD1, TARDBP, and VAPB; 50% included or offered the option of including C9orf72 hexanucleotide repeat expansion (HRE) analysis. Of the 91 genes included in at least one of the panels, 40 (44.0%) were included on only a single panel. We could not find a direct link to ALS in the literature for 14 (15.4%) included genes. Conclusions: The variability across the surveyed clinical genetic panels is concerning due to the possibility of reduced diagnostic yields in clinical practice and risk of a missed diagnoses for patients. Our results highlight the necessity for consensus regarding the appropriateness of gene inclusions in clinical genetic ALS tests to improve its application for patients living with ALS and their families.
Background and aimsCarotid atherosclerosis is an important cause of ischemic stroke. Lipids play a key role in the progression of atherosclerosis. To date, the spatial lipid profile of carotid atherosclerotic plaques related to histology has not been systematically investigated.MethodsCarotid atherosclerosis samples from 12 patients were obtained and classified into four classical pathological stages (preatheroma, atheroma, fibroatheroma and complicated lesion) by histological staining. Desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) was used to investigate the lipid profile of carotid atherosclerosis, and correlated it with histological information. Bioinformatics technology was used to process MSI data among different pathological stages of atherosclerosis lesions.ResultsA total of 55 lipids (26 throughout cross-section regions [TCSRs], 13 in lipid-rich regions [LRRs], and 16 in collagen-rich regions [CRRs]) were initially identified in carotid plaque from one patient. Subsequently, 32 of 55 lipids (12 in TCSRs, eight in LRRs, and 12 in CRRs) were further screened in 11 patients. Pathway enrichment analysis showed that multiple metabolic pathways, such as fat digestion and absorption, cholesterol metabolism, lipid and atherosclerosis, were enriched in TCSRs; sphingolipid signaling pathway, necroptosis pathway were enriched in LRRs; and glycerophospholipid metabolism, ether lipid metabolism pathway were mainly enriched in CRRs.ConclusionsThis study comprehensively showed the spatial lipid metabolism footprint in human carotid atherosclerotic plaques. The lipid profiles and related metabolism pathways in three regions of plaque with disease progression were different markedly, suggesting that the different metabolic mechanisms in these regions of carotid plaque may be critical in atherosclerosis progression.
Electromagnetic tomography is a process detection technology based upon the principles of electromagnetic induction. The forward problem model and sensitivity distribution matrix of electromagnetic tomography are introduced as the basis of the inverse problem. The search direction and iterative parameters of the conjugate gradient algorithm are modified to improve the quality and convergence of image reconstruction. A new spectral parameter conjugate gradient algorithm is described to modify the search direction, which is used to control the angle between the old and new search directions. The search direction is determined according to the iteration of each step in order to find the optimal solution. Combining the advantages of the Fletcher-Reeves and Polak-Ribiere-Polyak algorithms in the nonlinear conjugate gradient algorithm, they are mixed in a specific proportion to obtain a new hybrid conjugate gradient algorithm. In order to verify the effectiveness of the modified conjugate gradient algorithm, three physical models of electromagnetic tomography system are constructed, and the modified conjugate gradient algorithm is compared with the traditional algorithm. The experimental results show that the reconstructed image quality of the modified spectral conjugate gradient algorithm is higher and has better numerical performance. The hybrid conjugate gradient algorithm highlights the advantages of the Fletcher-Reeves and Polak-Ribiere-Polyaks algorithms. The convergence speed is faster than the Polak-Ribiere-Polyak method, and the imaging quality is higher than the other algorithms.
Vincetoxicum mongolicum Maxim. (1876), is a perennial medicinal herb, widely distributed in the Loess Plateau of China. Here, we sequenced, assembled, and annotated the complete chloroplast (cp) genome of V. mongolicum, and compared the highly variable gene regions and phylogenetic positions between V. mongolicum and other related species. Results showed that the complete cp genome of V. mongolicum was 160,157 bp in length, containing a large single copy (LSC) region of 91,263 bp, a pair of inverted repeats (IR) region of 23,892 bp, and a small single copy (SSC) region of 21,110 bp. The GC content accounts for 37.8%, and we annotated 131 single genes, which include 86 protein-coding genes, 8 rRNA genes, and 37 tRNA genes. By comparing and analyzing the variable region of the cp gene of V. mongolicum and other Vincetoxicum, we found that the variable sequences of rpoC1-rpoB, ycf4-cemA, ndhF, ndhF-rpl32, and rpl32-ccsA fragments were highly significant, which could be targeted as the DNA barcodes for evidence of V. mongolicum and its relatives in Apocynaceae. Maximum-likelihood (ML) phylogenetic tree analysis elucidated that V. mongolicum was sister to V. pycnostelma with strong support. Our results provide useful information for future phylogenetic studies and plastid super-barcodes of the family Apocynaceae.
Stipa bungeana Trin. 1833 is an important forage grass in Poaceae, widely distributed in the temperate steppe of Northern China, with strong grazing tolerance and feeding value. In this study, we performed the complete chloroplast (cp) genome sequence of S. bungeana to explore its phylogenetic position with other Stipa. The results showed that the circular complete cp genome of S. bungeana was 137,759 bp in length, including a large single copy (LSC) of 81,652 bp, a small single copy (SSC) of 12,817 bp, and two inverted repeats (IR) of 21,645 bp. The GC content accounts for 43.71% and annotated 134 single genes, which include 87 protein-coding genes, eight rRNA genes, and 39 tRNA genes. Maximum-likelihood (ML) phylogenetic tree suggested that the S. bungeana was closely related to other Stipa except for S. purpurea.
Abstract Background Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by predominant impairment of upper and lower motor neurons. Over 50 TARDBP mutations have been reported in both familial (FALS) and sporadic ALS (SALS). Some mutations in TARDBP, e.g. A382T and G294V, have genetic founder effects in certain geographic regions. However, such prevalence and founder effect have not been reported in Chinese. Methods Whole-exome sequencing (WES) was performed in 16 Chinese FALS patients, followed by Sanger sequencing for the TARDBP p.Gly298Ser mutation (G298S) in 798 SALS patients and 1,325 controls. Haplotype analysis using microsatellites flanking TARDBP was conducted in the G298S-carrying patients and noncarriers. The geographic distribution and phenotypic correlation of the TARDBP mutations reported worldwide were reviewed. Results WES detected the TARDBP G298S mutation in 8 FALS patients, and Sanger sequencing found additional 8 SALS cases, but no controls, carrying this mutation. All the 16 cases came from Southern China, and 7 of these patients shared the 117-286-257-145-246-270 allele for the D1S2736-D1S1151-D1S2667-D1S489-D1S434-D1S2697 markers, which was not found in the 92 non-carrier patients (0/92) (p < 0.0001) and 65 age-matched and neurologically normal individuals (0/65) (p < 0.0001). The A382T and G298S mutations were prevalent in Europeans and Eastern Asians, respectively. Additionally, carriers for the M337V mutation are dominated by bulbar onset with a long survival, whereas those for G298S are dominated by limb onset with a short survival. Conclusions Some prevalent TARDBP mutations are distributed in a geographic pattern and related to clinical profiles. TARDBP G298S mutation is a founder mutation in the Southern Chinese ALS population.
ObjectivesTo develop and validate a predictive nomogram for idiopathic rapid eye movement (REM) sleep behavior disorder (RBD) in a community population in Beijing, China.MethodsBased on the validated RBD questionnaire-Hong Kong (RBDQ-HK), we identified 78 individuals with possible RBD (pRBD) in 1,030 community residents from two communities in Beijing. The least absolute shrinkage and selection operator (LASSO) regression was applied to identify candidate features and develop the nomogram. Internal validation was performed using bootstrap resampling. The discrimination of the nomogram was evaluated using the area under the curve (AUC) of the receiver operating characteristic (ROC) curve, and the predictive accuracy was assessed via a calibration curve. Decision curve analysis (DCA) was performed to evaluate the clinical value of the model.ResultsFrom 31 potential predictors, 7 variables were identified as the independent predictive factors and assembled into the nomogram: family history of Parkinson's disease (PD) or dementia [odds ratio (OR), 4.59; 95% confidence interval (CI), 1.35–14.45; p = 0.011], smoking (OR, 3.24; 95% CI, 1.84–5.81; p < 0.001), physical activity (≥4 times/week) (OR, 0.23; 95% CI, 0.12–0.42; p < 0.001), exposure to pesticides (OR, 3.73; 95%CI, 2.08–6.65; p < 0.001), constipation (OR, 6.25; 95% CI, 3.58–11.07; p < 0.001), depression (OR, 3.66; 95% CI, 1.96–6.75; p < 0.001), and daytime somnolence (OR, 3.28; 95% CI, 1.65–6.38; p = 0.001). The nomogram displayed good discrimination, with original AUC of 0.885 (95% CI, 0.845–0.925), while the bias-corrected concordance index (C-index) with 1,000 bootstraps was 0.876. The calibration curve and DCA indicated the high accuracy and clinical usefulness of the nomogram.ConclusionsThis study proposed an effective nomogram with potential application in the individualized prediction for pRBD.
Prunus humilis (2n = 2x = 16) is a dwarf shrub fruit tree native to China and distributed widely in the cold and arid northern region. In this study, we obtained the whole genome sequences of P. humilis by combining Illumina, PacBio and HiC sequencing technologies. This genome was 254.38 Mb long and encodes 28,301 putative proteins. Phylogenetic analysis indicated that P. humilis shares the same ancestor with Prunus mume and Prunus armeniaca at similar to 29.03 Mya. Gene expansion analysis implied that the expansion of WAX-related and LEA genes might be associated with high drought tolerance of P. humilis and LTR maybe one of the driver factors for the drought adaption by increase the copy number of LEAs. Population diversity analysis among 20 P. humilis accessions found that the genetic diversity of P. humilis populations was limited, only 1.40% base pairs were different with each other, and more wild resources need to be collected and utilized in the breeding and improvement. This study provides new insights to the drought adaption and population diversity of P. humilis that could be used as a potential model plant for horticultural research.
Background and Objectives:Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is a rare hereditary cerebrovascular disease caused by homozygous or compound heterozygous variations in the high-temperature requirement A serine peptidase 1 (HTRA1) gene. However, several studies in recent years have found that some heterozygous HTRA1 mutations also cause cerebral small vessel disease (CSVD). The current study aims to report the novel genotypes, phenotypes, and histopathologic results of 3 pedigrees of CSVD with heterozygous HTRA1 mutation.Methods:Three pedigrees of familiar CSVD, including 11 symptomatic patients and 3 asymptomatic carriers, were enrolled. Whole-exome sequencing was conducted in the probands for identifying rare variants, which were then evaluated for pathogenicity according to the American College of Medical Genetics and Genomics guidelines. Sanger sequencing was performed for validation of mutations in the probands and other family members. The protease activity was assayed for the novel mutations. All the participants received detailed clinical and imaging examinations and the corresponding results were concluded. Hematoma evacuation was performed for an intracerebral hemorrhage patient with the p.Q318H mutation, and the postoperative pathology including hematoma and cerebral small vessels were examined.Results:Three novel heterozygous HTRA1 mutations (p.Q318H, p.V279M, and p.R274W) were detected in the 3 pedigrees. The protease activity was largely lost for all the mutations, confirming that they were loss-of-function mutations. The patients in each pedigree presented with typical clinical and imaging features of CVSD, and some of them displayed several new phenotypes including color blindness, hydrocephalus, and multiple arachnoid cysts. In addition, family 1 is the largest pedigree with heterozygous HTRA1 mutation so far and includes homozygous twins, displaying some variation in clinical phenotypes. More importantly, pathologic study of a patient with p.Q318H mutation showed hyalinization, luminal stenosis, loss of smooth muscle cells, splitting of the internal elastic lamina, and intramural hemorrhage/dissection-like structures.Discussion:These findings broaden the mutational and clinical spectrum of heterozygous HTRA1-related CSVD. Pathologic features were similar with the previous heterozygous and homozygous cases. Moreover, clinical heterogeneity was revealed within the largest single family, and the mechanisms of the phenotypic heterogenetic remain unclear. Overall, heterozygous HTRA1-related CSVD should not be simply taken as a mild type of CARASIL as previously considered.