32 research outputs found
Further delineation of the clinical spectrum of White-Sutton syndrome: 12 new individuals and a review of the literature
White–Sutton syndrome (WHSUS) is a neurodevelopmental disorder caused by heterozygous loss-of-function variants in POGZ. Through the Deciphering Developmental Disorders study and clinical testing, we identified 12 individuals from 10 families with pathogenic or likely pathogenic variants in POGZ (eight de novo and two inherited). Most individuals had delayed development and/or intellectual disability. We analyzed the clinical findings in our series and combined it with data from 89 previously reported individuals. The results demonstrate WHSUS is associated with variable developmental delay or intellectual disability, increased risk of obesity, visual defects, craniofacial dysmorphism, sensorineural hearing loss, feeding problems, seizures, and structural brain malformations. Our series includes further individuals with rod-cone dystrophy, cleft lip and palate, congenital diaphragmatic hernia, and duplicated renal drainage system, suggesting these are rare complications of WHSUS. In addition, we describe an individual with a novel, de novo missense variant in POGZ and features of WHSUS. Our work further delineates the phenotypic spectrum of WHSUS highlighting the variable severity of this disorder and the observation of familial pathogenic POGZ variants
Delineation of phenotypes and genotypes related to cohesin structural protein RAD21
RAD21 encodes a key component of the cohesin complex, and variants in RAD21 have been associated with Cornelia de Lange Syndrome (CdLS). Limited information on phenotypes attributable to RAD21 variants and genotype–phenotype relationships is currently published. We gathered a series of 49 individuals from 33 families with RAD21 alterations [24 different intragenic sequence variants (2 recurrent), 7 unique microdeletions], including 24 hitherto unpublished cases. We evaluated consequences of 12 intragenic variants by protein modelling and molecular dynamic studies. Full clinical information was available for 29 individuals. Their phenotype is an attenuated CdLS phenotype compared to that caused by variants in NIPBL or SMC1A for facial morphology, limb anomalies, and especially for cognition and behavior. In the 20 individuals with limited clinical information, additional phenotypes include Mungan syndrome (in patients with biallelic variants) and holoprosencephaly, with or without CdLS characteristics. We describe several additional cases with phenotypes including sclerocornea, in which involvement of the RAD21 variant is uncertain. Variants were frequently familial, and genotype–phenotype analyses demonstrated striking interfamilial and intrafamilial variability. Careful phenotyping is essential in interpreting consequences of RAD21 variants, and protein modeling and dynamics can be helpful in determining pathogenicity. The current study should be helpful when counseling families with a RAD21 variation.Spanish Ministry of Science, Innovation and Universities/State Research Agency RTC-2017-6494-1 and RTI2018-094434-B-I00 (MCIU/AEI/FEDER, UE) as well as funds from the European JPIAMR-VRI network “CONNECT” to PG-
Börjeson–Forssman–Lehmann syndrome: Delineating the clinical and allelic spectrum in 14 new families
Börjeson-Forssman-Lehmann syndrome (BFLS) is an X-linked intellectual disability syndrome caused by variants in the PHF6 gene. We ascertained 19 individuals from 15 families with likely pathogenic or pathogenic PHF6 variants (11 males and 8 females). One family had previously been reported. Six variants were novel. We analysed the clinical and genetic findings in our series and compared them with reported BFLS patients. Affected males had classic features of BFLS including intellectual disability, distinctive facies, large ears, gynaecomastia, hypogonadism and truncal obesity. Carrier female relatives of affected males were unaffected or had only mild symptoms. The phenotype of affected females with de novo variants overlapped with the males but included linear skin hyperpigmentation and a higher frequency of dental, retinal and cortical brain anomalies. Complications observed in our series included keloid scarring, digital fibromas, absent vaginal orifice, neuropathy, umbilical hernias, and talipes. Our analysis highlighted sex-specific differences in PHF6 variant types and locations. Affected males often have missense variants or small in-frame deletions while affected females tend to have truncating variants or large deletions/duplications. Missense variants were found in a minority of affected females and clustered in the highly constrained PHD2 domain of PHF6. We propose recommendations for the evaluation and management of BFLS patients. These results further delineate and extend the genetic and phenotypic spectrum of BFLS
POU3F3-related disorder: Defining the phenotype and expanding the molecular spectrum
POU3F3 variants cause developmental delay, behavioral problems, hypotonia and dysmorphic features. We investigated the phenotypic and genetic landscape, and genotype-phenotype correlations in individuals with POU3F3-related disorders. We recruited unpublished individuals with POU3F3 variants through international collaborations and obtained updated clinical data on previously published individuals. Trio exome sequencing or single exome sequencing followed by segregation analysis were performed in the novel cohort. Functional effects of missense variants were investigated with 3D protein modeling. We included 28 individuals (5 previously published) from 26 families carrying POU3F3 variants; 23 de novo and one inherited from an affected parent. Median age at study inclusion was 7.4 years. All had developmental delay mainly affecting speech, behavioral difficulties, psychiatric comorbidities and dysmorphisms. Additional features included gastrointestinal comorbidities, hearing loss, ophthalmological anomalies, epilepsy, sleep disturbances and joint hypermobility. Autism, hearing and eye comorbidities, dysmorphisms were more common in individuals with truncating variants, whereas epilepsy was only associated with missense variants. In silico structural modeling predicted that all (likely) pathogenic variants destabilize the DNA-binding region of POU3F3. Our study refined the phenotypic and genetic landscape of POU3F3-related disorders, it reports the functional properties of the identified pathogenic variants, and delineates some genotype-phenotype correlations
Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study
Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation
Novel therapeutic approaches for shock and systemic inflammation
Sepsis is the leading cause of mortality in non-coronary intensive care units and its incidence is set to rise. Despite advances in patient care, novel therapeutic interventions (with the exception of activated protein C) have failed to demonstrate benefit in clinical trials. High density lipoprotein has been widely reported to possess immunomodulatory properties and has been shown to be beneficial in animal models of systemic inflammation and sepsis. This thesis investigates the hypothesis that lysophospholipids, which are derivatives of high density lipoprotein, and other lipoproteins, display similar immunomodulatory properties. I have administered Gram-negative (lipopolysaccharide) or Gram-positive (peptidoglycan and lipoteichoic acid) cell wall components in anaesthetised rats to cause shock, organ injury/dysfunction and systemic inflammation. Subsequently, I have investigated the effects of various lysophospholipids in these models. I have demonstrated that therapeutic administration of lysophosphatidylcholine (LPC) dose-dependently attenuates the organ injury/dysfunction caused by administration of lipopolysaccharide. Furthermore, I have shown that LPC is also protective in a model of systemic inflammation caused by eo-administration of peptidoglycan and lipoteichoic acid. Lastly, I have reported that the beneficial effects of LPC discovered here can be demonstrated with an LPC derived from a natural source or with synthetic LPC. In addition, I have found that both saturated and unsaturated lysophosphatidic acid (LP A) significantly reduces the organ injury associated with systemic inflammation associated with endotoxic shock. The observed beneficial effects of LP A are dependant on acyl chain saturation, as saturated LP A only activates specific G-protein coupled receptors, while unsaturated LP A activates both G-protein coupled receptors and peroxisome proliferator-activated receptor-y. Finally, I have established that sphingosylphosphorylcholine attenuates the organ injury/dysfunction caused by administration of lipopolysaccharide. These beneficial effects were associated with potent anti-inflammatory effects, which include the reduction in the formation of pro-inflammatory cytokines, adhesion molecules, COX- 2 and iNOS expression and the recruitment of neutrophils.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
BRCA gene testing in women with high-grade serous ovarian carcinoma
The objective of this study was to compare the pick-up rate of pathogenic BRCA variants in those with a high-grade serous ovarian carcinoma (HGSOC) undergoing oncology-led testing with the traditional genetics family history-based testing model. With novel therapies, BRCA status can affect treatment. Welsh oncologists are now testing all women with HGSOC at diagnosis rather than referring to genetics, where family history is required for testing. The records of 332 women who underwent testing via oncology were analysed. The outcome measures were; percentage of women with a pathogenic BRCA variant and the difference in identification of pathogenic BRCA variants between the oncology-led and traditional genetics testing models. Of the 332 women, 25 women (7.5%) tested positive for a pathogenic BRCA variant. This was slightly lower than the detection rate of 9.8% for patients tested via the genetics service over the same period. Testing through genetics, using family history criteria would have identified only 19 (76%) of those with pathogenic variants in the oncology cohort. Since women with a pathogenic BRCA variant can be offered life-extending targeted treatment and a significant proportion of these women would be missed if testing was offered based on family history criteria alone, universal BRCA testing of all women with HGSOC is justified.Impact statement: What is already known on this subject? It is well established that individuals with a strong family history of breast and ovarian cancer are more likely to carry a pathogenic BRCA gene variant. With the use of tools such as the Manchester scoring system women are often invited for testing through clinical genetics services. Until recently there was no clinical impact for those already diagnosed with ovarian cancer. What do the results of this study add? Our study has shown that the diagnosis of high grade serious ovarian carcinoma alone without the need for any family history leads to a similar rate of detection of pathogenic BRCA variants as traditional methods. With the advent of targeted treatments such as olaparib, women with a pathogenic BRCA variant can access different life extending treatment options. With comparable pick-up rates to traditional family history based scoring systems, oncologists can now arrange BRCA gene testing directly. What are the implications of these findings for clinical practice and/or further research? Our study shows universal genetic testing of those with high-grade serious ovarian carcinoma by oncologists allows more women to access life extending treatment in a shorter timeframe compared to the traditional testing model used by clinical genetics services. We hope that other centres, both in the UK and beyond, will adopt this approach
Lysophosphatidylcholine reduces the organ injury and dysfunction in rodent models of Gram-negative and Gram-positive shock
1 Lysophosphatidylcholine (LPC) modulates the inflammatory response and reduces mortality in animal models of sepsis. Here, we investigate the effects of LPC from synthetic (sLPC) and natural, soy bean derived LPC, (nLPC) sources on the organ injury/dysfunction caused by systemic administration of lipopolysaccharide (LPS) or peptidoglycan (PepG) and lipoteichoic acid (LTA). 2 Rats were subjected to (i) endotoxaemia (LPS 6 mg kg(-1) i.v.) and treated with sLPC (1-100 mg kg(-1)), (ii) endotoxaemia and treated with nLPC (10 mg kg(-1)) or (iii) Gram-positive shock (PepG 10 mg kg(-1) and LTA 3 mg kg(-1) i.v.) and treated with sLPC (10 mg kg(-1)). 3 Endotoxaemia or Gram-positive shock for 6 h resulted. in increases in serum makers of renal dysfunction and liver, pancreatic and neuromuscular injury. 4 Administration of sLPC, at 1 or 2 It after LPS, dose dependently (1-10 mg kg(-1)) reduced the organ injury/dysfunction. High doses of sLPC (30 and 100 mg kg(-1)) were shown to be detrimental in endotoxaemia. sLPC also afforded protection against the organ injury/dysfunction caused by Gram-positive shock. nLPC was found to be protective in endotoxaemic animals. 5 The beneficial effects of sLPC were associated with an attenuation in circulating levels of interleukin-1 beta (IL-1 beta). 6 In conclusion, LPC dose and time dependently reduces the organ injury and circulating IL-1 beta levels caused by Gram-negative or Gram-positive shock in the rat. Thus, we speculate that appropriate doses of LPC may be useful in reducing the degree of organ injury and dysfunction associated with shock of various aetiologies
A mild case of acromesomelic dysplasia, type Maroteaux with novel natriuretic peptide receptor B (NPR2) variants
Acromesomelic dysplasia, type Maroteaux is caused by variants in NPR2. It is a severe chondrodysplasia resulting in shortening of the middle and distal segments of the limbs. Limb length at birth may be normal but decreased growth becomes obvious in the first 2 years of life. Here we present an 11-year-old male with mild but typical skeletal features of acromesomelic dysplasia, type Maroteaux. Whole exome sequencing has identified two likely pathogenic variants in NPR2 which have not previously been reported in individuals with acromesomelic dysplasia, type Maroteaux. Given these findings, a diagnosis of AMDM should be considered in individuals with characteristic radiological findings, even if stature is only modestly affected