Successful Management of Gorham-Stout Disease in Scapula and Ribs: A Case Report and Literature Review.

Orthop Surg. 2018 Aug 12;:

Authors: Li MH, Zhang HQ, Lu YJ, Gao P, Huang H, Hu YC, Wang Z

Abstract
Gorham-Stout disease (GSD) is an extremely rare bone condition of unknown etiology characterized by spontaneous and progressive resorption of bones. GSD can occur at any age and is not related to gender, genetic inheritance, or race. Any part of the skeleton can be affected and the symptoms correlate with the sites involved. The diagnosis of GSD is established based on the combination of clinical, radiologic, and histologic features after excluding other diseases. Because of its rarity, current knowledge is limited to case reports and there is no agreement on the best strategy for treatment. The following case report describes a successfully treated case of GSD in a 26-year-old male patient with the left scapula and the 7th-9th left ribs involved. The patient was diagnosed with osteoporosis-related pleural effusion at a local hospital. In our institution, the patient was diagnosed with GSD and treated with radiotherapy and bisphosphonate. The disease was controlled and there was no evidence of disease progression during follow-up. Genetic sequencing was performed to investigate the etiology of GSD. In addition, the present study reviews the theories regarding the etiology, the clinical manifestations, the diagnostic approaches, and treatment options for this rare disease.

PMID: 30101546 [PubMed - as supplied by publisher]

Development of an evidence-based algorithm that optimizes sensitivity and specificity in ES-based diagnostics of a clinically heterogeneous patient population.

Genet Med. 2018 Aug 13;:

Authors: Bauer P, Kandaswamy KK, Weiss MER, Paknia O, Werber M, Bertoli-Avella AM, Yüksel Z, Bochinska M, Oprea GE, Kishore S, Weckesser V, Karges E, Rolfs A

Abstract
PURPOSE: Next-generation sequencing (NGS) is rapidly replacing Sanger sequencing in genetic diagnostics. Sensitivity and specificity of NGS approaches are not well-defined, but can be estimated from applying NGS and Sanger sequencing in parallel. Utilizing this strategy, we aimed at optimizing exome sequencing (ES)-based diagnostics of a clinically diverse patient population.
METHODS: Consecutive DNA samples from unrelated patients with suspected genetic disease were exome-sequenced; comparatively nonstringent criteria were applied in variant calling. One thousand forty-eight variants in genes compatible with the clinical diagnosis were followed up by Sanger sequencing. Based on a set of variant-specific features, predictors for true positives and true negatives were developed.
RESULTS: Sanger sequencing confirmed 81.9% of ES-derived variants. Calls from the lower end of stringency accounted for the majority of the false positives, but also contained ~5% of the true positives. A predictor incorporating three variant-specific features classified 91.7% of variants with 100% specificity and 99.75% sensitivity. Confirmation status of the remaining variants (8.3%) was not predictable.
CONCLUSIONS: Criteria for variant calling in ES-based diagnostics impact on specificity and sensitivity. Confirmatory sequencing for a proportion of variants, therefore, remains a necessity. Our study exemplifies how these variants can be defined on an empirical basis.

PMID: 30100613 [PubMed - as supplied by publisher]

Identification of a novel PAFAH1B1 missense mutation as a cause of mild lissencephaly with basal ganglia calcification.

Brain Dev. 2018 Aug 09;:

Authors: Shi CH, Zhang S, Yang ZH, Li YS, Liu YT, Li Z, Hu ZW, Xu YM

Abstract
PURPOSE: To investigate the genetic and clinical features of a Chinese family exhibiting an autosomal dominant inheritance pattern of lissencephaly.
METHODS: Clinical examinations and cranial imaging studies were performed for all members of the family (two unaffected members and three surviving members from a total of four affected members). In addition, whole-exome sequencing analysis was performed for DNA from an affected patient to scan for candidate mutations, followed by Sanger sequencing to verify these candidate mutations in the entire family. A total of 200 ethnicity-matched healthy controls without neuropsychiatric disorder were also included and analyzed.
RESULTS: We identified a novel missense mutation, c.412G > A, p.(E138K), that cosegregated with the disease in exon 6 of the platelet activating factor acetylhydrolase 1b regulatory subunit 1 (PAFAH1B1) gene in the affected members; this mutation was not found in the 200 controls. Multiple sequence alignments showed that codon 138, where the mutation (c.G412A) occurred, was located within a phylogenetically conserved region. Brain magnetic resonance imaging revealed calcification within the bilateral globus pallidus in all three affected members.
CONCLUSIONS: We identified a novel missense mutation, c.412G > A, p.(E138K),in the PAFAH1B1 gene of a Chinese family with lissencephaly. In addition, our findings suggest that basal ganglia calcification is a novel clinical feature of PAFAH1B1-related lissencephaly.

PMID: 30100227 [PubMed - as supplied by publisher]

Biallelic Mutations in ADPRHL2, Encoding ADP-Ribosylhydrolase 3, Lead to a Degenerative Pediatric Stress-Induced Epileptic Ataxia Syndrome.

Am J Hum Genet. 2018 Jul 25;:

Authors: Ghosh SG, Becker K, Huang H, Salazar TD, Chai G, Salpietro V, Al-Gazali L, Waisfisz Q, Wang H, Vaux KK, Stanley V, Manole A, Akpulat U, Weiss MM, Efthymiou S, Hanna MG, Minetti C, Striano P, Pisciotta L, De Grandis E, Altmüller J, Nürnberg P, Thiele H, Yis U, Okur TD, Polat AI, Amiri N, Doosti M, Karimani EG, Toosi MB, Haddad G, Karakaya M, Wirth B, van Hagen JM, Wolf NI, Maroofian R, Houlden H, Cirak S, Gleeson JG

Abstract
ADP-ribosylation, the addition of poly-ADP ribose (PAR) onto proteins, is a response signal to cellular challenges, such as excitotoxicity or oxidative stress. This process is catalyzed by a group of enzymes referred to as poly(ADP-ribose) polymerases (PARPs). Because the accumulation of proteins with this modification results in cell death, its negative regulation restores cellular homeostasis: a process mediated by poly-ADP ribose glycohydrolases (PARGs) and ADP-ribosylhydrolase proteins (ARHs). Using linkage analysis and exome or genome sequencing, we identified recessive inactivating mutations in ADPRHL2 in six families. Affected individuals exhibited a pediatric-onset neurodegenerative disorder with progressive brain atrophy, developmental regression, and seizures in association with periods of stress, such as infections. Loss of the Drosophila paralog Parg showed lethality in response to oxidative challenge that was rescued by human ADPRHL2, suggesting functional conservation. Pharmacological inhibition of PARP also rescued the phenotype, suggesting the possibility of postnatal treatment for this genetic condition.

PMID: 30100084 [PubMed - as supplied by publisher]

A case of interdigitating dendritic cell sarcoma studied by whole-exome sequencing.

Genes Genomics. 2018 Aug 11;:

Authors: Hong KH, Song S, Shin W, Kang K, Cho CS, Hong YT, Han K, Moon JH

Abstract
Interdigitating dendritic cell sarcoma (IDCS) is an aggressive neoplasm and is an extremely rare disease, with a challenging diagnosis. Etiology of IDCS is also unknown and most studies with only case reports. In our case, immunohistochemistry showed that the tumor cells were positive for S100, CD45, and CD68, but negative for CD1a and CD21. This study aimed to investigate the causative factors of IDCS by sequencing the protein-coding regions of IDCS. We performed whole-exome sequencing with genomic DNA from blood and sarcoma tissue of the IDCS patient using the Illumina Hiseq 2500 platform. After that, we conducted Sanger sequencing for validation of sarcoma-specific variants and gene ontology analysis using DAVID bioinformatics resources. Through comparing sequencing data of sarcoma with normal blood, we obtained 15 nonsynonymous single nucleotide polymorphisms (SNPs) as sarcoma-specific variants. Although the 15 SNPs were not validated by Sanger sequencing due to tumor heterogeneity and low sensitivity of Sanger sequencing, we examined the function of the genes in which each SNP is located. Based on previous studies and gene ontology database, we found that POLQ encoding DNA polymerase theta enzyme and FNIP1 encoding tumor suppressor folliculin-interacting protein might have contributed to the IDCS. Our study provides potential causative genetic factors of IDCS and plays a role in advancing the understanding of IDCS pathogenesis.

PMID: 30099721 [PubMed - as supplied by publisher]

[Analysis of clinical manifestation and genetic mutation in a child with X-linked chondrodysplasia punctata 2].

Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2018 Aug 10;35(4):527-530

Authors: Chang G, Zhou Y, Yin L, Gu L, Ying D, Chen H, Wang X, Wang J

Abstract
OBJECTIVE: To analyze clinical manifestations and genetic mutation in a child with severe short stature and other malformations.
METHODS: The child has undergone history taking and physical examination. Genome DNA was extracted from peripheral blood samples of the proband and her family members. Candidate genes were captured with Agilent SureSelect and sequenced on an Illumina platform. Suspected mutation was verified by Sanger sequencing.
RESULTS: The patient, a six-year-and-10-month old girl, presented with non-symmetrical short stature, dysmorphism, abnormalities of limbs and spine, amblyopia of left eye, and cataract of right eye, in addition with frequent respiratory infection and micturition. Laboratory testing suggested 25-hydroxy vitamin D deficiency (18.9 ng/mL). Spine X-ray showed multiple malformations with centrums. Her mother also featured short stature (138 cm). Her aunt had short stature (130 cm) and limb-length discrepancy. Her little brother was 2.5 years old, and his height was 81 cm (-3.4 SD). Exome sequencing revealed a heterozygous mutation c.184C to T (p.Arg62Trp) in the proband and her mother. The same mutation was not found in her father and brother.
CONCLUSION: The patient was diagnosed with X-linked chondrodysplasia punctata 2. Mutation of the EBP gene probably underlied the disease in this family.

PMID: 30098249 [PubMed - in process]

[Analysis of NF1 gene mutations among eleven sporadic patients with neurofibromatosis type 1].

Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2018 Aug 10;35(4):480-483

Authors: Peng C, Ma S, Tang X, Yang J

Abstract
OBJECTIVE: To explore the genetic etiology for 11 sporadic patients with neurofibromatosis type 1.
METHODS: Chip targeting capture and high-throughput sequencing were employed to detect potential mutations of NF1 and NF2 genes among the 11 patients. The data was filtered through multiple mutational databases and in-house whole exome sequence database. Sanger sequencing was used for analysis of family members of the patients.
RESULTS: Eleven pathogenic variants were found among the 11 patients, which included two splicing mutations, one missense mutation, two nonsense mutations, and six frame-shifting mutations. None of the mutations was recorded by the public database or the in-house database generated from 1775 samples through whole exome sequencing. None of the unaffected parents carried the same mutation. Seven mutations were associated with neurofibromatosis type 1 previously, while the remaining four were discovered for the first time. Prenatal diagnosis of two high-risk pregnancies suggested that neither fetus has inherited the NF1 mutation from their affected parents.
CONCLUSION: Identification of causative mutations in patients with sporadic-type neurofibromatosis type 1 has provided a basis for genetic counseling. The four novel mutations have enriched the spectrum of NF1 gene mutations.

PMID: 30098238 [PubMed - in process]

Characterization of three ciliopathy pedigrees expands the phenotype associated with biallelic C2CD3 variants.

Eur J Hum Genet. 2018 Aug 10;:

Authors: Boczek NJ, Hopp K, Benoit L, Kraft D, Cousin MA, Blackburn PR, Madsen CD, Oliver GR, Nair AA, Na J, Bianchi DW, Beek G, Harris PC, Pichurin P, Klee EW

Abstract
Whole exome sequencing (WES) is utilized in diagnostic odyssey cases to identify the underlying genetic cause associated with complex phenotypes. Recent publications suggest that WES reveals the genetic cause in ~25% of these cases and is most successful when applied to children with neurological disease. The residual 75% of cases remain genetically elusive until more information becomes available in the literature or functional studies are pursued. WES performed on three families with presumed ciliopathy diagnoses, including orofaciodigital (OFD) syndrome, fetal encephalocele, or Joubert-related disorder, identified compound heterozygous variants in C2CD3. Biallelic variants in C2CD3 have previously been associated with ciliopathies, including OFD syndrome type 14 (OFD14; MIM: 615948). As three of the six identified variants were predicted to affect splicing, exon-skipping analysis using either RNA sequencing or PCR-based methods were completed to determine the pathogenicity of these variants, and showed that each of the splicing variants led to a frameshifted protein product. Using these studies in combination with the 2015 ACMG guidelines, each of the six identified variants were classified as either pathogenic or likely pathogenic, and are therefore likely responsible for our patients' phenotypes. Each of the families had a distinct clinical phenotype and severity of disease, extending from lethal to viable. These findings highlight that there is a broad phenotypic spectrum associated with C2CD3-mediated disease and not all patients present with the typical features of OFD14.

PMID: 30097616 [PubMed - as supplied by publisher]

High genetic carrier frequency of Wilson's disease in France: discrepancies with clinical prevalence.

BMC Med Genet. 2018 Aug 10;19(1):143

Authors: Collet C, Laplanche JL, Page J, Morel H, Woimant F, Poujois A

Abstract
BACKGROUND: Wilson's disease (WD) is a rare autosomal recessive metabolic disease caused by ATP7B gene mutations tat cause excessively high copper levels, particularly in the liver and brain. The WD phenotype varies in terms of its clinical presentation and intensity. Diagnosing this metabolic disorder is important as a lifelong treatment, based on the use of copper chelating agents or zinc salts, is more effective if it's started early. Worldwide prevalence of WD is variable, with an average of 1/30,000. In France, a recent study based on French health insurance data estimated the clinical prevalence of the disease to be around 3/200,000.
METHODS: To estimate the genetic prevalence of WD in France, we analysed the ATP7B gene by Next Generation Sequencing from a large French cohort of indiscriminate subjects.
RESULTS: We observed a high heterozygous carrier frequency of ATP7B in France. Among the 697 subjects studied, 18 variants classified as pathogenic or probably pathogenic were found at heterozygous level in 22 subjects (22 alleles/1394 alleles), yielding a prevalence of 0.032 or 1/31 subjects.
CONCLUSIONS: This considerable and unexplained discrepancy between the heterozygous carrier frequency and the clinical prevalence of WD may be explained by the clinical variability, the incomplete penetrance and the existence of modifiers genes. It suggests that the molecular analysis of ATP7B should be interpreted with caution, always alongside copper assays (ceruloplasmin, relative exchangeable copper, 24 h-urinary copper excretion) with particular respect to exome sequencing.

PMID: 30097039 [PubMed - in process]

Renal hypouricemia caused by novel compound heterozygous mutations in the SLC22A12 gene: a case report with literature review.

BMC Med Genet. 2018 Aug 10;19(1):142

Authors: Zhou Z, Ma L, Zhou J, Song Z, Zhang J, Wang K, Chen B, Pan D, Li Z, Li C, Shi Y

Abstract
BACKGROUND: Renal hypouricemia (RHUC) is a heterogeneous genetic disorder that is characterized by decreased serum uric acid concentration and increased fractional excretion of uric acid. Previous reports have revealed many functional mutations in two urate transporter genes, SLC22A12 and/or SLC2A9, to be the causative genetic factors of this disorder. However, there are still unresolved patients, suggesting the existence of other causal genes or new mutations. Here, we report an RHUC patient with novel compound heterozygous mutations in the SLC22A12 gene.
CASE PRESENTATION: A 27-year-old female presenting with recurrent hypouricemia during routine checkups was referred to our hospital. After obtaining the patient's consent, both the patient and her healthy parents were analyzed using whole-exome sequencing (WES) and Sanger sequencing to discover and validate causal mutations, respectively. The prioritization protocol of WES screened out two mutations of c.269G > A/p.R90H and c.1289_1290insGG/p.M430fsX466, which are both located in the SLC22A12 gene, in the patient. Sanger sequencing further confirmed that the patient's heterozygous c.269G > A/p.R90H mutation, which has been reported previously, derived from her mother, and the heterozygous c.1289_1290insGG/p.M430fsX466 mutation, which was found for the first time, derived from her father. p.R90H, which is highly conserved among different species, may decrease the stability of this domain and was considered to be almost damaging in silicon analysis. p.M430fsX466 lacks the last three transmembrane domains, including the tripeptide motif (S/T)XΦ (X = any amino acid and Φ = hydrophobic residue), at the C-terminal, which interact with scaffolding protein PDZK1 and thus will possibly lead to weak functioning of urate transport through the disruption of the "transporter complex" that is formed by URAT1 and PDZK1.
CONCLUSIONS: We report a Chinese patient with RHUC, which was caused by compound heterozygous mutations of the SLC22A12 gene, using WES and Sanger sequencing for the first time. Mutation-induced structural instability or malfunction of the urate transporter complex may be the main mechanisms for this hereditary disorder.

PMID: 30097038 [PubMed - in process]

CRISPLD1 rs12115090 polymorphisms alters antiplatelet potency of clopidogrel in coronary artery disease patients in Chinese Han.

Gene. 2018 Aug 07;:

Authors: Wang JY, Zhang YJ, Li H, Hu XL, Li MP, Song PY, Ma QL, Peng LM, Chen XP

Abstract
BACKGROUND: Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is a recommended treatment for coronary artery disease (CAD) patients undergoing percutaneous coronary intervention (PCI) to reduce the rate of ischemic events and stent thrombosis. However, high on-treatment platelet reactivity (HTPR) during clopidogrel therapy for some patients may lead to outcome failure and occurrence of cardiovascular events. Amounts of studies have proved that genetic factors may contribute to HTPR. In our study, we explored the predictive value of 10 single nucleotide polymorphisms (SNPs) in 8 genes indicated by exome sequencing with clopidogrel efficacy.
METHODS: Two hundred and forty-one Han Chinese CAD patients (mean age: 61 ± 10 years) receiving dual antiplatelet therapy were recruited, among which 118 patients administered with 300 mg loading dose (LD) clopidogrel for 12-24 h and 123 subjects administered with 75 mg/day maintain dose (MD) clopidogrel for at least 5 days before discharge. The platelet reaction index (PRI) was determined to reflect clopidogrel response in the patients. Venous blood samples were drawn from all participants to extract genomic DNA. MassARRAY, Sanger sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) were used to determine the genotypes of 10 SNPs.
RESULTS: Allelic tests showed significant differences in genotype distribution between HTPR and normal on-treatment platelet reactivity (NTPR) patients for 3 SNPs including CYP2C19 rs4244285 (CYP2C19*2) (co-dominant model: p = 0.003, dominant model: p = 0.004, recessive model: p = 0.012), CRISPLD1 rs12115090 (co-dominant model: p = 0.011, dominant model: p = 0.004), and LTA4H rs11108379 (dominant model: p = 0.041). After adjusting for covariates including clinical characteristics of patients, concomitant medications and complications, we confirmed that carriers of the CYP2C19*2 showed significantly increased risk of HTPR (*2/*2 vs *1/*1: OR = 12.266, 95% CI: 1.336-112.592, p = 0.027; *1/*2 + *2/*2 vs *1/*1: OR = 2.202, 95% CI: 1.083-4.480, p = 0.029). Contrarily, carriers of the CRISPLD1 rs12115090 C allele showed significantly reduced risk of HTPR (CC vs AA: OR = 0.242, 95% CI: 0.078-0.752, p = 0.014; CA + CC vs AA: OR = 0.457, 95% CI: 0.232-0.904, p = 0.024) in Chinese CAD patients. In addition, carriers of the CYP2C19*2 allele showed was significantly increased PRI (*1/*2 vs *1/*1: p = 0.008, 2/*2 vs 1/*1: p < 0.001, *2/*2 vs 1/*2: p = 0.011), while patients carrying the rs12115090 C allele showed significantly decreased PRI than the wild-type AA homozygotes (CA vs AA: p = 0.046, CA + CC vs AA: p = 0.023).
CONCLUSION: CYP2C19*2 reduced the antiplatelet potency of clopidogrel and increased the risk of HTPR, while CRISPLD1 rs12115090 A>C polymorphism increased the antiplatelet potency of clopidogrel. Genetic tests, especially for CYP2C19*2 are recommended in Han Chinese CAD patients before using of clopidogrel.

PMID: 30096456 [PubMed - as supplied by publisher]

A novel CRX frameshift mutation causing cone-rod dystrophy in a Chinese family: A case report.

Medicine (Baltimore). 2018 Aug;97(32):e11499

Authors: Wang L, Qi A, Pan H, Liu B, Feng J, Chen W, Wang B

Abstract
BACKGROUND: Cone-rod dystrophy (CORD) is an inherited, progressive retinal disorder with genetic and phenotypic heterogeneity. Here, we aimed to identify the pathogenic mutation in affected individuals in a Chinese family with autosomal dominant cone-rod dystrophy (adCORD).
METHODS: Genomic DNA and clinical examination results were collected from a Chinese family presenting with adCORD. The candidate disease-causing mutations were screened with whole-exome sequencing (WES) and bioinformatics analyses. Sanger sequencing was used for validation and cosegregation analysis.
RESULTS: A novel frameshift mutation (NM_000554.4; c.538dupG:p.Val180fs) in exon 4 of the CRX gene was identified in all affected individuals in the Chinese family with adCORD. Cosegregation analysis confirmed that this mutation was cosegregated with the disease. This variant, which results in premature termination of the protein, was absent from all public variant databases or internal exome databases.
CONCLUSIONS: We used whole-exome sequencing to identify a novel CRX mutation causing adCORD in a Chinese family. This study broadens the known pathogenic mutation spectrum of the CRX gene and shows the potential of WES in identifying the pathogenic mutations of CORD disease.

PMID: 30095615 [PubMed - in process]

Identification of a novel mutation of RUNX2 in a family with supernumerary teeth and craniofacial dysplasia by whole-exome sequencing: A case report and literature review.

Medicine (Baltimore). 2018 Aug;97(32):e11328

Authors: Ma D, Wang X, Guo J, Zhang J, Cai T

Abstract
RATIONALE: Supernumerary teeth are those that teeth in excess number than the normal count. It is usually associated with genetic syndromes when present in more numbers. Several causal genes, such as APC, NHS, TRPS1, EVC and RUNX2, have been identified. However, etiology of supernumerary teeth remains largely unclear.
PATIENT CONCERNS: A family with the clinical diagnosis of supernumerary teeth, short stature and craniofacial dysplasia was examined.
DIAGNOSES: Molecular genetic analysis found that mutation occurred in the RUNX2 gene. On the basis of this finding and clinical manifestations, the final diagnosis of cleidocranial dysplasia was made.
INTERVENTIONS: Whole exome sequencing (WES) of DNA samples was performed to identify the disease-causing mutation, including the affected child and mother as well as the healthy father.
OUTCOMES: A novel mutation of RUNX2 (c.473C>A; p.A158E) was identified in both patients, but not in normal family member and in-house database containing 3,000 Chinese Han individuals WES. This mutation was further confirmed by Sanger sequencing and predicted to be deleterious by several commonly used algorithms, including SIFT, PPT-2, MutationTaster and Proven. Furthermore, phenotype-genotype correlation analyses of all published 239 cases with different mutations in RUNX2 revealed significant association of supernumerary teeth and facial dysplasia with the Runt domain of the encoded protein.
LESSONS: This is the first WES study to identify genetic cause in Chinese patients with a novel RUNX2 mutation. Our findings expanded the mutation spectrum and clinical features of the disease and facilitated clinic diagnosis and genetic counseling.

PMID: 30095610 [PubMed - in process]

Reversible deficits in apical transporter trafficking associated with DGAT1 deficiency.

Traffic. 2018 Aug 10;:

Authors: Schlegel C, Lapierre LA, Weis VG, Williams JA, Kaji I, Pinzon-Guzman C, Prasad N, Boone B, Jones A, Correa H, Levy SE, Han X, Wang M, Thomsen K, Acra S, Goldenring JR

Abstract
Deficiency in diacylglycerol acyltransferase (DGAT1) is a rare cause of neonatal diarrhea, without a known mechanism or in vitro model.
METHODS AND RESULTS: A patient presenting at our institution at 7 weeks of life with failure to thrive and diarrhea was found by whole-exome sequencing to have a homozygous DGAT1 truncation mutation. Duodenal biopsies showed loss of DGAT1 and deficits in apical membrane transporters and junctional proteins in enterocytes. When placed on a very low-fat diet, the patient's diarrhea resolved with normalization of brush border transporter localization in endoscopic biopsies. DGAT1 knockdown in Caco2-BBe cells modeled the deficits in apical trafficking, with loss of apical DPPIV and junctional occludin. Elevation in cellular lipid levels, including diacylglycerol (DAG) and phospholipid metabolites of DAG, was documented by lipid analysis in DGAT1 knockdown cells. Culture of the DGAT1 knockdown cells in lipid-depleted media led to re-establishment of occludin and return of apical DPPIV.
DISCUSSION: DGAT1 loss appears to elicit global changes in enterocyte polarized trafficking that could account for deficits in absorption seen in the patient. The in vitro modeling of this disease should allow for investigation of possible therapeutic targets. This article is protected by copyright. All rights reserved.

PMID: 30095213 [PubMed - as supplied by publisher]

Recurrent diffuse lung disease due to surfactant protein C deficiency.

Respir Med Case Rep. 2018;25:91-95

Authors: Kazzi B, Lederer D, Arteaga-Solis E, Saqi A, Chung WK

Abstract
Surfactant protein C (SP-C) deficiency causes diffuse lung disease with variable prognosis and severity that usually presents in infancy. We present the case of a patient with diffuse lung disease who was successfully treated with hydroxychloroquine and steroids in infancy, who presented again as a young adult with respiratory symptoms. Exome sequencing identified a novel de novo SFTPC mutation (c.397A > C p.S133R). Mutated SP-C accumulates and leads to injury of alveolar type II cells, which normally replenish alveolar type I cells after injury. This may explain the symptom recurrence after lung injury in young adulthood. Although hydroxychloroquine has been hypothesized to interfere with mutated SP-C accumulation, data on long term outcome remains limited.

PMID: 30094155 [PubMed]

Genetics of migraine.

Handb Clin Neurol. 2018;148:493-503

Authors: Anttila V, Wessman M, Kallela M, Palotie A

Abstract
Genetics of migraine has recently undergone a major shift, moving in the space of a few years from having only a few known genes for rare Mendelian forms to 47 known common variant loci affecting the susceptibility of the common forms of migraine. This has largely been achieved by rapidly increasing sample sizes for genomewide association studies (GWAS), soon to be followed by the first wave of large-scale exome-sequencing studies. The large number of detected loci, chief among them TRPM8, PRDM16, and LRP1, have enabled a number of in silico analyses, which have shed light on the functional and tissue-level aspects of the common risk variants for migraine, including evidence for involvement of both vascular and neuronal mechanisms. Polygenic risk scores and other measures of genetic variance based on GWAS information are further opening the door to dissecting pharmacogenetics, functional etiology, and comorbidity. Heritability-based analyses are demonstrating strong links between migraine and other neuropsychiatric disorders and brain phenotypes, highlighting genetic links between migraine and major depressive disorder and attention-deficit hyperactivity disorder, among others. These recent successes in migraine genetics are starting to be mature enough to provide robust evidence of specific quantifiable genetic factors in common migraine.

PMID: 29478595 [PubMed - indexed for MEDLINE]

Suspicion of mitochondrial disease remains frequently unconfirmed after whole exome sequencing.

Mol Genet Metab Rep. 2018 Sep;16:66

Authors: Finsterer J, Zarrouk-Mahjoub S

PMID: 30090701 [PubMed]

The Whole Exome Sequencing Clarifies the Genotype- Phenotype Correlations in Patients with Early-Onset Dementia.

Aging Dis. 2018 Aug;9(4):696-705

Authors: Xu Y, Liu X, Shen J, Tian W, Fang R, Li B, Ma J, Cao L, Chen S, Li G, Tang H

Abstract
Our study aimed to identify the underlying causes in patients with early onset dementia by clinical and genetic exploration. We recruited a group of 38 patients with early-onset dementia. Firstly, hexanucleotide repeat expansions in C9ORF72 gene were screened in all subjects to exclude the possibility of copy number variation. Then, the whole exome sequencing (WES) was conducted, and the data were analyzed focusing on 89 dementia-related causing and susceptible genes. The effects of identified variants were classified according to the American College of Medical Genetics and Genomics (ACMG) standards and guidelines. There were no pathogenic expansions in C9ORF72 detected. According to the ACMG standards and guidelines, we identified five known pathogenic mutations, PSEN1 P284L, PSEN1c.857-1G>A, PSEN1 I143T, PSEN1 G209E and MAPT G389R, and one novel pathogenic mutation APP K687N. All these mutations caused dementia with the mean onset age of 38.3 (range from 27 to 51) and rapid progression. Eleven variants with uncertain significance were also detected and needed further verification. The clinical phenotypes of dementia are heterogeneous, with both onset ages and clinical features being influenced by mutation position as well as the causative gene. WES can serve as efficient diagnostic tools for different heterogeneous dementia.

PMID: 30090657 [PubMed]

Nephrotic syndrome and adrenal insufficiency caused by a variant in SGPL1.

Clin Kidney J. 2018 Aug;11(4):462-467

Authors: Linhares ND, Arantes RR, Araujo SA, Pena SDJ

Abstract
Little is known about the molecular pathogenesis of congenital nephrotic syndrome in association with primary adrenal insufficiency. Most recently, three groups found concurrently the underlying genetic defect in the gene sphingosine-1-phosphate lyase 1 (SGPL1) and called the disease nephrotic syndrome type 14 (NPHS14). In this report we have performed whole-exome sequencing and identified a new homozygous variant in SGPL1, p.Arg340Trp, in a girl with nephrotic syndrome and Addison's disease. Her brother died previously with the same phenotype and hyperpigmentation of the skin. We reviewed the reported cases and concluded that NPHS14 is a clinically recognizable syndrome. The discovery of this syndrome may contribute to the diagnosis and description of additional patients who could benefit from treatment, genetic counseling and screening for related comorbidities. Until now, patients with congenital nephrotic syndrome associated with primary adrenal insufficiency have been treated as having two different diseases; however, the treatment for patients with NPHS14 should be unique, possibly targeting the sphingolipid metabolism.

PMID: 30090628 [PubMed]

Rare Disease Diagnostics: A Single-center Experience and Lessons Learnt.

Rambam Maimonides Med J. 2018 Jul 30;9(3):

Authors: Weiss K, Kurolap A, Paperna T, Mory A, Steinberg M, Hershkovitz T, Ekhilevitch N, Baris HN

Abstract
OBJECTIVE: The growing availability of next-generation sequencing technologies has revolutionized medical genetics, facilitating discovery of causative genes in numerous Mendelian disorders. Nevertheless, there are still many undiagnosed cases. We report the experience of the Genetics Institute at Rambam Health Care Campus in rare disease diagnostics using whole-exome sequencing (WES).
METHODS: Phenotypic characterization of patients was done in close collaboration with referring physicians. We utilized WES analysis for diagnosing families suspected for rare genetic disorders. Bioinformatic analysis was performed in-house using the Genoox analysis platform.
RESULTS: Between the years 2014 and 2017, we studied 34 families. Neurological manifestations were the most common reason for referral (38%), and 55% of families were consanguineous. A definite diagnosis was reached in 21 cases (62%). Four cases (19%) were diagnosed with variants in novel genes. In addition, six families (18%) had strong candidate novel gene discoveries still under investigation. Therefore, the true diagnosis rate is probably even higher. Some of the diagnoses had a significant impact such as alerting the patient management and providing a tailored treatment.
CONCLUSIONS: An accurate molecular diagnosis can set the stage for improved patient care and provides an opportunity to study disease mechanisms, which may lead to development of tailored treatments. Data from our genetic research program demonstrate high diagnostic and novel disease-associated or causative gene discovery rates. This is likely related to the unique genetic architecture of the population in Northern Israel as well as to our strategy for case selection and the close collaboration between analysts, geneticists, and clinicians, all working in the same hospital.

PMID: 30089087 [PubMed]