Sex in Plasmodium falciparum: Silence Play between GDV1 and HP1.

Trends Parasitol. 2018 May 08;:

Authors: Rea E, Le Roch KG, Tewari R

Abstract
Understanding how malaria parasites commit to sexual development is key to the development of transmission-blocking strategies. Recent work by Filarsky and colleagues extends our understanding of the molecular mechanisms driving this process by characterizing an early factor in gametocytogenesis, and showing how this fits neatly into our current knowledge of sexual commitment.

PMID: 29752147 [PubMed - as supplied by publisher]

Application of molecular cytogenetic techniques to characterize the aberrant Y chromosome arising de novo in a male fetus with mosaic 45,X and solve the discrepancy between karyotyping, chromosome microarray, and multiplex ligation dependent probe amplification.

J Formos Med Assoc. 2018 May 08;:

Authors: Lin SY, Lee CN, Peng AY, Yuan TJ, Lee DJ, Lin WH, Ma GC, Chen M

Abstract
We present a rare male fetus with karyotype of mosaic 45,X that comprises two types of aberrant Y chromosomes arising de novo (Yq12 deletion and isodicentric Yq11.22). Both types of the aberrant Y chromosomes lack the AZFc region which are expected to result in oligospermia but unaffected male external genitalia. Genetic analyses by karyotyping, chromosome microarray (CMA), and multiplex ligation-dependent probe amplification (MLPA) for the fetus revealed conflicting results. Additional molecular cytogenetics tools including fluorescence in situ hybridization (FISH) and multicolor banding (mBAND) were performed, which help resolving the discrepancy and delineated the composition of the aberrant Y chromosomes. This report highlighted the importance of incorporating multiple genetic technologies for accurate characterization of complex chromosomal rearrangements, which aid in the prenatal diagnosis and genetic counseling.

PMID: 29752043 [PubMed - as supplied by publisher]

Genome-Wide Identification and Analysis of Arabidopsis Sodium Proton Antiporter (NHX) and Human Sodium Proton Exchanger (NHE) Homologs in Sorghum bicolor.

Genes (Basel). 2018 May 03;9(5):

Authors: Hima Kumari P, Anil Kumar S, Ramesh K, Sudhakar Reddy P, Nagaraju M, Bhanu Prakash A, Shah T, Henderson A, Srivastava RK, Rajasheker G, Chitikineni A, Varshney RK, Rathnagiri P, Lakshmi Narasu M, Kavi Kishor PB

Abstract
Na⁺ transporters play an important role during salt stress and development. The present study is aimed at genome-wide identification, in silico analysis of sodium-proton antiporter (NHX) and sodium-proton exchanger (NHE)-type transporters in Sorghum bicolor and their expression patterns under varied abiotic stress conditions. In Sorghum, seven NHX and nine NHE homologs were identified. Amiloride (a known inhibitor of Na⁺/H⁺ exchanger activity) binding motif was noticed in both types of the transporters. Chromosome 2 was found to be a hotspot region with five sodium transporters. Phylogenetic analysis inferred six ortholog and three paralog groups. To gain an insight into functional divergence of SbNHX/NHE transporters, real-time gene expression was performed under salt, drought, heat, and cold stresses in embryo, root, stem, and leaf tissues. Expression patterns revealed that both SbNHXs and SbNHEs are responsive either to single or multiple abiotic stresses. The predicted protein⁻protein interaction networks revealed that only SbNHX7 is involved in the calcineurin B-like proteins (CBL)- CBL interacting protein kinases (CIPK) pathway. The study provides insights into the functional divergence of SbNHX/NHE transporter genes with tissue specific expressions in Sorghum under different abiotic stress conditions.

PMID: 29751546 [PubMed]

Therapeutic Potential of Sclareol in Experimental Models of Rheumatoid Arthritis.

Int J Mol Sci. 2018 May 03;19(5):

Authors: Tsai SW, Hsieh MC, Li S, Lin SC, Wang SP, Lehman CW, Lien CZ, Lin CC

Abstract
Previous studies have shown that the natural diterpene compound, sclareol, potentially inhibits inflammation, but it has not yet been determined whether sclareol can alleviate inflammation associated with rheumatoid arthritis (RA). Here, we utilized human synovial cell line, SW982, and an experimental murine model of rheumatoid arthritis, collagen-induced arthritis (CIA), to evaluate the therapeutic effects of sclareol in RA. Arthritic DBA/1J mice were dosed with 5 and 10 mg/kg sclareol intraperitoneally every other day over 21 days. Arthritic severity was evaluated by levels of anti-collagen II (anti-CII) antibody, inflammatory cytokines, and histopathologic examination of knee joint tissues. Our results reveal that the serum anti-CII antibody, cytokines interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and IL-17, as well as Th17 and Th1 cell population in inguinal lymph nodes, were significantly lower in sclareol-treated mice compared to the control group. Also, the sclareol treatment groups showed reduced swelling in the paws and lower histological arthritic scores, indicating that sclareol potentially mitigates collagen-induced arthritis. Furthermore, IL-1β-stimulated SW982 cells secreted less inflammatory cytokines (TNF-α and IL-6), which is associated with the downregulation of p38-mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK), and NF-κB pathways. Overall, we demonstrate that sclareol could relieve arthritic severities by modulating excessive inflammation and our study merits the pharmaceutical development of sclareol as a therapeutic treatment for inflammation associated with RA.

PMID: 29751535 [PubMed - in process]

Long-term safety and efficacy of the novel β3 -adrenoreceptor agonist vibegron in Japanese patients with overactive bladder: A phase III prospective study.

Int J Urol. 2018 May 11;:

Authors: Yoshida M, Kakizaki H, Takahashi S, Nagai S, Kurose T

Abstract
OBJECTIVES: To evaluate the long-term safety and efficacy of vibegron 50 mg and 100 mg, a novel β3 -adrenoreceptor agonist, in Japanese patients with overactive bladder.
METHODS: This was a 1-year, multicenter, open-label, non-controlled study. After a 1-week observation phase, patients were treated with vibegron for 52 weeks. When the efficacy was insufficient after an 8-week treatment with 50 mg, the dose was increased to 100 mg and maintained for an additional 44 weeks.
RESULTS: Among a total of 169 patients receiving one or more doses of vibegron, 118 (69.8%) received vibegron 50 mg for 52 weeks, and the dose was increased to 100 mg in 51 (30.2%) patients. The incidence of drug-related adverse events was 18.1% (21/116) in the vibegron 50 mg group and 11.8% (6/51) in the vibegron 100 mg group. Most frequent drug-related adverse events were dry mouth (3.0%), residual urine volume increased (3.0%), constipation (2.4%) and cystitis (1.8%). Statistically significant changes in overactive bladder symptom variables (daily means of micturitions, urgency episodes, urgency incontinence episodes, incontinence episodes and night-time frequency) from baseline were observed at week 4 and maintained until week 52. The condition of patients who did not respond well to vibegron 50 mg was much improved by increasing the dose to 100 mg. Vibegron improved the quality of life, and the proportion of patients' satisfaction after the treatment with vibegron was high.
CONCLUSIONS: Long-term (52-week) treatment with vibegron is safe, well-tolerated and effective in patients with overactive bladder.

PMID: 29752752 [PubMed - as supplied by publisher]

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Carpal tunnel syndrome in mucopolysaccharidosis: the value of rare disease registries.

Dev Med Child Neurol. 2017 12;59(12):1213-1214

Authors: White KK

PMID: 28940237 [PubMed - indexed for MEDLINE]

Ion Channel Modulators in Cystic Fibrosis.

Chest. 2018 May 08;:

Authors: Gentzsch M, Mall MA

Abstract
Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and remains one of the most common life-shortening genetic diseases affecting the lung and other organs. CFTR functions as a cAMP-dependent anion channel that transports chloride and bicarbonate across epithelial surfaces and disruption of these ion transport processes plays a central role in the pathogenesis of CF. These findings provided the rationale for pharmacological modulation of ion transport, either by targeting mutant CFTR or alternative ion channels that can compensate for CFTR dysfunction, as a promising therapeutic approach. High throughput screening has supported the development of CFTR modulator compounds. CFTR correctors are designed to improve defective protein processing, trafficking and cell surface expression, whereas potentiators increase the activity of mutant CFTR at the cell surface. The approval of the first potentiator ivacaftor for the treatment of patients with specific CFTR mutations and, more recently the corrector lumacaftor in combination with ivacaftor for patients homozygous for the common F508del mutation, were major breakthroughs on the path to causal therapies for all patients with CF. In this review, we focus on recent developments and remaining challenges of CFTR-directed therapies, as well as modulators of other ion channels such as alternative chloride channels and the epithelial sodium channel (ENaC) as additional targets in CF lung disease. Further, we discuss how patient-derived precision medicine models may aid the translation of emerging next generation ion channel modulators from the laboratory to the clinic and tailor their use for optimal therapeutic benefits in individual patients with CF.

PMID: 29750923 [PubMed - as supplied by publisher]

Reply.

Gastroenterology. 2018 May 08;:

Authors: Hadjiliadis D, Khoruts A, Zauber AG, Hempstead SE, Maisonneuve P, Lowenfels AB

PMID: 29750906 [PubMed - as supplied by publisher]

CFTR dysfunction in cystic fibrosis and chronic obstructive pulmonary disease.

Expert Rev Respir Med. 2018 May 11;:

Authors: Fernandez Fernandez E, de Santi C, De Rose V, Greene CM

Abstract
INTRODUCTION: Obstructive lung diseases such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) are causes of high morbidity and mortality worldwide. CF is a multiorgan genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and is characterized by progressive chronic obstructive lung disease. Most cases of COPD are a result of noxious particles, mainly cigarette smoke but also other environmental pollutants. Areas covered: Although the pathogenesis and pathophysiology of CF and COPD differ, they do share key phenotypic features and because of these similarities there is great interest in exploring common mechanisms and/or factors affected by CFTR mutations and environmental insults involved in COPD. Various molecular, cellular and clinical studies have confirmed that CFTR protein dysfunction is common in both the CF and COPD airways. This review provides an update of our understanding of the role of dysfunctional CFTR in both respiratory diseases. Expert Commentary: Drugs developed for people with CF to improve mutant CFTR function and enhance CFTR ion channel activity might also be beneficial in patients with COPD. A move toward personalized therapy using, for example, microRNA modulators in conjunction with CFTR potentiators or correctors, could enhance treatment of both diseases.

PMID: 29750581 [PubMed - as supplied by publisher]

Recurrent somatic mutations are rare in patients with cryptic dyskeratosis congenita.

Leukemia. 2018 Apr 02;:

Authors: Kirschner M, Maurer A, Wlodarski MW, Ventura Ferreira MS, Bouillon AS, Halfmeyer I, Blau W, Kreuter M, Rosewich M, Corbacioglu S, Beck J, Schwarz M, Bittenbring J, Radsak MP, Wilk CM, Koschmieder S, Begemann M, Kurth I, Schemionek M, Brümmendorf TH, Beier F

Abstract
Dyskeratosis congenita (DKC) is a paradigmatic telomere disorder characterized by substantial and premature telomere shortening, bone marrow failure, and a dramatically increased risk of developing myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). DKC can occur as a late-onset, so-called cryptic form, with first manifestation in adults. Somatic MDS-related mutations are found in up to 35% of patients with acquired aplastic anemia (AA), especially in patients with short telomeres. The aim of our study was to investigate whether cryptic DKC is associated with an increased incidence of MDS-related somatic mutations, thereby linking the accelerated telomere shortening with the increased risk of MDS/AML. Samples from 15 adult patients (median age: 42 years, range: 23-60 years) with molecularly confirmed cryptic DKC were screened using next-generation gene panel sequencing to detect MDS-related somatic variants. Only one of the 15 patients (7%) demonstrated a clinically relevant MDS-related somatic variant. This incidence was dramatically lower than formerly described in acquired AA. Based on our data, we conclude that clonal evolution of subclones carrying MDS-related mutations is not the predominant mechanism for MDS/AML initiation in adult cryptic DKC patients.

PMID: 29749397 [PubMed - as supplied by publisher]

Data from the US and UK cystic fibrosis registries support disease modification by CFTR modulation with ivacaftor.

Thorax. 2018 May 10;:

Authors: Bessonova L, Volkova N, Higgins M, Bengtsson L, Tian S, Simard C, Konstan MW, Sawicki GS, Sewall A, Nyangoma S, Elbert A, Marshall BC, Bilton D

Abstract
BACKGROUND: Ivacaftor is the first cystic fibrosis transmembrane conductance regulator (CFTR) modulator demonstrating clinical benefit in patients with cystic fibrosis (CF). As ivacaftor is intended for chronic, lifelong use, understanding long-term effects is important for patients and healthcare providers.
OBJECTIVE: This ongoing, observational, postapproval safety study evaluates clinical outcomes and disease progression in ivacaftor-treated patients using data from the US and the UK CF registries following commercial availability.
METHODS: Annual analyses compare ivacaftor-treated and untreated matched comparator patients for: risks of death, transplantation, hospitalisation, pulmonary exacerbation; prevalence of CF-related complications and microorganisms and lung function changes in a subset of patients who initiated ivacaftor in the first year of commercial availability. Results from the 2014 analyses (2 and 3 years following commercial availability in the UK and USA, respectively) are presented here.
RESULTS: Analyses included 1256 ivacaftor-treated and 6200 comparator patients from the USA and 411 ivacaftor-treated and 2069 comparator patients from the UK. No new safety concerns were identified based on the evaluation of clinical outcomes included in the analyses. As part of safety evaluations, ivacaftor-treated US patients were observed to have significantly lower risks of death (0.6% vs 1.6%, p=0.0110), transplantation (0.2% vs 1.1%, p=0.0017), hospitalisation (27.5% vs 43.1%, p<0.0001) and pulmonary exacerbation (27.8% vs 43.3%, p<0.0001) relative to comparators; trends were similar in the UK. In both registries, ivacaftor-treated patients had a lower prevalence of CF-related complications and select microorganisms and had better preserved lung function.
CONCLUSIONS: While general limitations of observational research apply, analyses revealed favourable results for clinically important outcomes among ivacaftor-treated patients, adding to the growing body of literature supporting disease modification by CFTR modulation with ivacaftor.
EU PAS REGISTRATION NUMBER: EUPAS4270.

PMID: 29748252 [PubMed - as supplied by publisher]

Effective silencing of ENaC by siRNA delivered with epithelial-targeted nanocomplexes in human cystic fibrosis cells and in mouse lung.

Thorax. 2018 May 10;:

Authors: Tagalakis AD, Munye MM, Ivanova R, Chen H, Smith CM, Aldossary AM, Rosa LZ, Moulding D, Barnes JL, Kafetzis KN, Jones SA, Baines DL, Moss GWJ, O'Callaghan C, McAnulty RJ, Hart SL

Abstract
INTRODUCTION: Loss of the cystic fibrosis transmembrane conductance regulator in cystic fibrosis (CF) leads to hyperabsorption of sodium and fluid from the airway due to upregulation of the epithelial sodium channel (ENaC). Thickened mucus and depleted airway surface liquid (ASL) then lead to impaired mucociliary clearance. ENaC regulation is thus a promising target for CF therapy. Our aim was to develop siRNA nanocomplexes that mediate effective silencing of airway epithelial ENaC in vitro and in vivo with functional correction of epithelial ion and fluid transport.
METHODS: We investigated translocation of nanocomplexes through mucus and their transfection efficiency in primary CF epithelial cells grown at air-liquid interface (ALI).Short interfering RNA (SiRNA)-mediated silencing was examined by quantitative RT-PCR and western analysis of ENaC. Transepithelial potential (Vt), short circuit current (Isc), ASL depth and ciliary beat frequency (CBF) were measured for functional analysis. Inflammation was analysed by histological analysis of normal mouse lung tissue sections.
RESULTS: Nanocomplexes translocated more rapidly than siRNA alone through mucus. Transfections of primary CF epithelial cells with nanocomplexes targeting αENaC siRNA, reduced αENaC and βENaC mRNA by 30%. Transfections reduced Vt, the amiloride-sensitive Isc and mucus protein concentration while increasing ASL depth and CBF to normal levels. A single dose of siRNA in mouse lung silenced ENaC by approximately 30%, which persisted for at least 7 days. Three doses of siRNA increased silencing to approximately 50%.
CONCLUSION: Nanoparticle-mediated delivery of ENaCsiRNA to ALI cultures corrected aspects of the mucociliary defect in human CF cells and offers effective delivery and silencing in vivo.

PMID: 29748250 [PubMed - as supplied by publisher]

A prospective analysis of unplanned patient-initiated contacts in an adult cystic fibrosis centre.

J Cyst Fibros. 2018 May 07;:

Authors: Burnet E, Hubert D, Champreux J, Honoré I, Kanaan R, Panzo R, Burgel PR

Abstract
BACKGROUND: Timely response should be provided when patients contact the cystic fibrosis (CF) centre in between scheduled visits. Little data exist on unplanned patient-initiated contacts in CF adults.
METHODS: A two-stage prospective study was undertaken from 1 January to 31 December 2015 at Cochin Hospital, Paris (France). The first stage included all adults (≥18 years) who initiated unplanned contacts to the CF centre over four months. Four physicians and three nurses systematically recorded unplanned patient-initiated contacts. The data was analysed to determine why and how patients contacted the CF centre and time spent responding to their request(s). The second stage (one physician, three nurses) lasted twelve months and explored whether high contact frequency was associated with disease severity, using multivariate logistic regression.
RESULTS: In the first stage, 259 of 410 patients (63%) initiated at least one unplanned contact, corresponding to 1067 contacts over 4 months. Patients favoured email with physicians (61% of contacts) and telephone with nurses (87% of contacts). Total time spent by the 7 caregivers on providing responses was 8 h/work week. Reasons for contacting the CF centre varied greatly, but <20% of contacts were directly related to symptom management. In the second stage, 180 of 212 patients (85%) initiated 1876 contacts over 12 months. Factors associated with ≥5 contacts/year were female sex, FEV1 ≤ 30% predicted, ≥5 physician visits/year, and ≥ 1 hospital admission/year.
CONCLUSIONS: Answering unplanned patient-initiated contacts represented a significant workload for CF caregivers. Increased disease severity was associated with high contact frequency.

PMID: 29748153 [PubMed - as supplied by publisher]

Physical activity patterns and clusters in 1001 patients with COPD.

Chron Respir Dis. 2017 Aug;14(3):256-269

Authors: Mesquita R, Spina G, Pitta F, Donaire-Gonzalez D, Deering BM, Patel MS, Mitchell KE, Alison J, van Gestel AJ, Zogg S, Gagnon P, Abascal-Bolado B, Vagaggini B, Garcia-Aymerich J, Jenkins SC, Romme EA, Kon SS, Albert PS, Waschki B, Shrikrishna D, Singh SJ, Hopkinson NS, Miedinger D, Benzo RP, Maltais F, Paggiaro P, McKeough ZJ, Polkey MI, Hill K, Man WD, Clarenbach CF, Hernandes NA, Savi D, Wootton S, Furlanetto KC, Cindy Ng LW, Vaes AW, Jenkins C, Eastwood PR, Jarreta D, Kirsten A, Brooks D, Hillman DR, Sant'Anna T, Meijer K, Dürr S, Rutten EP, Kohler M, Probst VS, Tal-Singer R, Gil EG, den Brinker AC, Leuppi JD, Calverley PM, Smeenk FW, Costello RW, Gramm M, Goldstein R, Groenen MT, Magnussen H, Wouters EF, ZuWallack RL, Amft O, Watz H, Spruit MA

Abstract
We described physical activity measures and hourly patterns in patients with chronic obstructive pulmonary disease (COPD) after stratification for generic and COPD-specific characteristics and, based on multiple physical activity measures, we identified clusters of patients. In total, 1001 patients with COPD (65% men; age, 67 years; forced expiratory volume in the first second [FEV1], 49% predicted) were studied cross-sectionally. Demographics, anthropometrics, lung function and clinical data were assessed. Daily physical activity measures and hourly patterns were analysed based on data from a multisensor armband. Principal component analysis (PCA) and cluster analysis were applied to physical activity measures to identify clusters. Age, body mass index (BMI), dyspnoea grade and ADO index (including age, dyspnoea and airflow obstruction) were associated with physical activity measures and hourly patterns. Five clusters were identified based on three PCA components, which accounted for 60% of variance of the data. Importantly, couch potatoes (i.e. the most inactive cluster) were characterised by higher BMI, lower FEV1, worse dyspnoea and higher ADO index compared to other clusters ( p < 0.05 for all). Daily physical activity measures and hourly patterns are heterogeneous in COPD. Clusters of patients were identified solely based on physical activity data. These findings may be useful to develop interventions aiming to promote physical activity in COPD.

PMID: 28774199 [PubMed - indexed for MEDLINE]

Forkhead box C1 gene variant causing glaucoma and small vessel angiopathy can mimic multiple sclerosis.

Mult Scler Relat Disord. 2018 Apr 21;22:157-160

Authors: Avasarala JR, Jones JR, Rogers CR

Abstract
A 34-year old Caucasian female was initially diagnosed with multiple small-vessel strokes at age 20 years which were etiologically classified as secondary to anti-phospholipid antibody syndrome (APS) although she had no history or laboratory data to suggest APS. Based on her MRI of brain findings, one of her neurologists was concerned she could have multiple sclerosis (MS) and hence the patient was referred to our clinic for further evaluation. The patient's MRI of brain showed confluent lesions in the periventricular and juxta-cortical lesions that fulfil 2017 McDonald criteria for dissemination in space. She had no symptoms other than occasional, mild headaches and had no findings to suggest clinically isolated syndrome (CIS) or MS; additionally, her cerebrospinal fluid analysis was unremarkable. Past history showed that she had undergone surgery for glaucoma, and subsequently developed bilateral sensorineural hearing loss in the third decade that was diagnosed as Meniere's disease. Her family history revealed that her son had dysmorphic facies and was small for age. He had a bifid uvula, bilaterally duplicated thumbs and scoliosis. Additionally, he had hypertelorism, a wide forehead and flattening of mid-face. Due to his complex medical presentation, whole exome sequencing (WES) was performed that revealed a maternally inherited heterozygous pathogenic frameshift in the FOXC1 gene. Genotyping of the mother showed the FOXC1 gene variant and adds to the growing list of differential diagnoses that may mimic MS in the context of radiological changes involving cerebral small vessels. This is the first report of a FOXC1 gene variant presenting with radiological features that can erroneously be interpreted as being consistent with MS.

PMID: 29751260 [PubMed - as supplied by publisher]

Whole Exome Sequencing of an Exceptional Longevity Cohort.

J Gerontol A Biol Sci Med Sci. 2018 May 10;:

Authors: Nygaard HB, Erson-Omay EZ, Wu X, Kent BA, Bernales CQ, Evans DM, Farrer MJ, Vilariño-Güell C, Strittmatter SM

Abstract
Centenarians represent a unique cohort to study the genetic basis for longevity and factors determining the risk of neurodegenerative disorders, including Alzheimer's disease (AD). The estimated genetic contribution to longevity is highest in centenarians and supercententenarians, but few genetic variants have been shown to clearly impact this phenotype. While the genetic risk for AD and other dementias is now well understood, the frequency of known dementia risk variants in centenarians is not fully characterized. To address these questions, we performed whole exome sequencing on 100 individuals of 98-108 years age in search of genes with large effect sizes towards the exceptional aging phenotype. Overall, we were unable to identify a rare protein-altering variant or individual genes with an increased burden of rare variants associated with exceptional longevity. Gene burden analysis revealed three genes of nominal statistical significance associated with extreme aging, including LYST, MDN1, and RBMXL1. Several genes with variants conferring an increased risk for AD and other dementias were identified, including TREM2, EPHA1, ABCA7, PLD3, MAPT, and NOTCH3. Larger centenarian studies will be required to further elucidate the genetic basis for longevity, and factors conferring protection against age-dependent neurodegenerative syndromes.

PMID: 29750252 [PubMed - as supplied by publisher]

Targeted exome sequencing reveals homozygous TREM2 R47C mutation presenting with behavioral variant frontotemporal dementia without bone involvement.

Neurobiol Aging. 2018 Apr 16;:

Authors: Ng AS, Tan YJ, Yi Z, Tandiono M, Chew E, Dominguez J, Macas M, Ng E, Hameed S, Ting S, Tan EK, Foo JN, Kandiah N

Abstract
To identify genes associated with frontotemporal dementia (FTD) in South-East Asia, targeted exome sequencing and C9orf72 genotyping was performed in 198 subjects (52 patients with FTD and 146 healthy controls) who were screened for mutations in 12 FTD-associated genes. We detected a homozygous TREM2 R47C mutation in a patient with behavioral variant FTD without bone cysts or bone-associated phenotype. Two novel nonsense GRN mutations in 3 FTD patients from the Philippines were detected, but no known pathogenic mutations in other FTD-associated genes were found. In 45 subjects screened for C9orf72 repeat expansions, no pathogenic expansion (≥30 repeats) was identified, but there was a higher proportion of intermediate length (≥10-29 repeats) alleles in patients compared with controls (8/90 alleles, 8.9% vs. 9/164 alleles, 5.5%). Overall, we detected a mutation rate of 7.7% (4/52 patients) in our cohort. Given recent findings of enrichment of rare TREM2 variants (including R47C) in Alzheimer's disease, it is notable that we detected a homozygous TREM2 R47C carrier presenting with an FTD rather than an Alzheimer's disease phenotype.

PMID: 29748150 [PubMed - as supplied by publisher]

Identification of the PROM1 Mutation p.R373C in a Korean Patient With Autosomal Dominant Stargardt-like Macular Dystrophy.

Ann Lab Med. 2017 Nov;37(6):536-539

Authors: Kim JM, Lee C, Lee GI, Kim NKD, Ki CS, Park WY, Kim BJ, Kim SJ

Abstract
Stargardt-like macular dystrophy 4 (STGD4) is a rare macular dystrophy characterized by bull's eye atrophy of the macula and the underlying retinal pigment epithelium. Patients with STGD4 show decreased central vision, which often progresses to severe vision loss. The PROM1 gene encodes prominin-1, which is a 5-transmembrane glycoprotein also known as CD133 and is involved in photoreceptor disk morphogenesis. PROM1 mutations have been identified as genetic causes for STGD4 and other retinal degenerations such as retinitis pigmentosa. We report a case of STGD4 with a PROM1 p.R373C mutation in a Korean patient. Ophthalmic examinations of a 38-yr old man complaining of decreased visual acuity revealed bilateral atrophic macular lesions consistent with STGD4. Targeted exome sequencing of known inherited retinal degeneration genes revealed a heterozygous missense mutation c.1117C>T (p.R373C) of PROM1, which was confirmed by Sanger sequencing. To the best of our knowledge, this is the first case of a PROM1 mutation causing STGD4 in Koreans.

PMID: 28840994 [PubMed - indexed for MEDLINE]