Short tandem repeats genotyping of gestational choriocarcinoma - our experiences.

OBJECTIVE: This short communication demonstrates how short tandem repeat genotyping can identify the origin of gestational choriocarcinoma. MATERIALS AND METHODS: The origin of gestational choriocarcinoma in our three cases was determined using the short tandem repeats genotyping technique, which involved quantitative fluorescent PCR and fragmentation analysis. RESULTS: In Case 1 despite no medical history of molar pregnancy, DNA analysis indicated that the choriocarcinoma originated from a homozygous complete hydatidiform mole. We conclude, that the patient's complete abortion 10 years prior to the choriocarcinoma diagnosis was an undiagnosed complete hydatidiform mole. In Case 2 and Case 3 the clinically presumed origin of choriocarcinoma was confirmed. CONCLUSION: Determining the origin of choriocarcinoma is essential for clinical application, as it affects the FIGO scoring system for gestational trophoblastic neoplasia, which determines the patient's prognosis and treatment approach.

Identification of copy neutral loss of heterozygosity on chromosomes 1p, 1q, and 6p among nonsyndromic cleft lip and/or without cleft palate with hypodontia.

BACKGROUND: Nonsyndromic cleft lip and/or without cleft palate (NSCL/P) with or without hypodontia is a common developmental aberration in humans and animals. This study aimed to identify the loss of heterozygosity (LOH) involved in hypodontia and NSCL/P pathogenesis. METHODS: This is a cross-sectional study that conducted genome-wide copy number analysis using CytoScan 750K array on salivary samples from Malay subjects with NSCL/P with or without hypodontia aged 7-13 years. To confirm the significant results, simple logistic regression was employed to conduct statistical data analysis using SPSS software. RESULTS: The results indicated the most common recurrent copy neutral LOH (cnLOH) observed at 1p33-1p32.3, 1q32.2-1q42.13 and 6p12.1-6p11.1 loci in 8 (13%), 4 (7%), and 3 (5%) of the NSCL/P subjects, respectively. The cnLOHs at 1p33-1p32.3 (D1S197), 1q32.2-1q42.13 (D1S160), and 6p12.1-6p11.1 (D1S1661) were identified observed in NSCL/P and noncleft children using microsatellite analysis markers as a validation analysis. The regions affected by the cnLOHs at 1p33-1p32.3, 1q32.2-1q42.13, and 6p12.1-6p11.1 loci contained selected genes, namely FAF1, WNT3A and BMP5, respectively. There was a significant association between the D1S197 (1p33-32.3) markers containing the FAF1 gene among NSCL/P subjects with or without hypodontia compared with the noncleft subjects (p-value = 0.023). CONCLUSION: The results supported the finding that the genetic aberration on 1p33-32.3 significantly contributed to the development of NSCL/P with or without hypodontia. These results have an exciting prospect in the promising field of individualized preventive oral health care.

Mismatch-repair deficiency, microsatellite instability, and lynch syndrome in ovarian cancer: A systematic review and meta-analysis.

OBJECTIVE: Investigating for mismatch repair protein deficiency (MMRd), microsatellite instability (MSI), and Lynch syndrome (LS) is widely accepted in endometrial cancer, but knowledge is limited on its value in epithelial ovarian cancer (EOC). The primary objective was to evaluate the prevalence of mismatch repair protein deficiency (MMRd), microsatellite instability (MSI)-high, and Lynch syndrome (LS) in epithelial ovarian cancer (EOC), as well as the diagnostic accuracy of LS screening tests. The secondary objective was to determine the prevalence of MMRd, MSI-high, and LS in synchronous ovarian endometrial cancer and in histological subtypes. METHODS: We systematically searched the MEDLINE, Epub Ahead of Print, MEDLINE In-Process and Other Non-Indexed Citations, Cochrane Central Register of Controlled Trials, and Embase databases. We included studies analysing MMR, MSI, and/or LS by sequencing. RESULTS: A total of 55 studies were included. The prevalence of MMRd, MSI-high, and LS in EOC was 6% (95% confidence interval (CI) 5-8%), 13% (95% CI 12-15%), and 2% (95% CI 1-3%) respectively. Hypermethylation was present in 76% of patients with MLH1 deficiency (95% CI 64-84%). The MMRd prevalence was highest in endometrioid (12%) followed by non-serous non-mucinous (9%) and lowest in serous (1%) histological subtypes. MSI-high prevalence was highest in endometrioid (12%) and non-serous non-mucinous (12%) and lowest in serous (9%) histological subtypes. Synchronous and endometrioid EOC had the highest prevalence of LS pathogenic variants at 7% and 3% respectively, with serous having lowest prevalence (1%). Synchronous ovarian and endometrial cancers had highest rates of MMRd (28%) and MSI-high (28%). Sensitivity was highest for IHC (91.1%) and IHC with MSI (92.8%), while specificity was highest for IHC with methylation (92.3%). CONCLUSION: MMRd and germline LS testing should be considered for non-serous non-mucinous EOC, particularly for endometrioid. PRECIS: The rates of mismatch repair deficiency, microsatellite instability high, and mismatch repair germline mutations are highest in endometrioid subtype and non-serous non-mucinous ovarian cancer. The rates are lowest in serous histologic subtype.

C9orf72 hexanucleotide repeat expansion found in suspected spinobulbar muscular atrophy (SBMA).

INTRODUCTION: The expansion of a hexanucleotide GGGGCC repeat (G4C2) in the C9orf72 locus is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). In addition, C9orf72 expansion has also been detected in patients with a clinical manifestation of Parkinson's Disease (PD), Alzheimer's Disease (AD), Huntington's Disease (HD), and ataxic disorders. MATERIAL AND METHODS: A total of 1,387 patients with clinically suspected ALS, HD or spinal and bulbar muscular atrophy (SBMA) were enrolled, and the prevalence of C9orf72 expansions was estimated. RESULTS: The hexanucleotide expansion accounted for 3.7% of the ALS patients, 0.2% of the HD suspected patients with excluded HTT mutation, and 1.3% of the suspected SBMA patients with excluded mutation in AR gene. CONCLUSIONS: This is the first report revealing the presence of C9orf72 expansion in patients with a suspected SBMA diagnosis. Consequently, we advise testing for C9orf72 expansion in patients presenting with the SBMA phenotype and a genetically unsolved diagnosis.

Clinical outcomes of metachronous recurrence of gastric epithelial neoplasia based on Helicobacter pylori infection status and microsatellite stability.

BACKGROUND/AIMS: Helicobacter pylori eradication may prevent the recurrence of gastric epithelial neoplasia after endoscopic treatment. However, H. pylori eradication therapy is unlikely to prevent gastric cancer. This study determined the longterm results and clinical outcomes of patients with gastric epithelial neoplasia based on H. pylori infection status and microsatellite stability (MSS). METHODS: Patients diagnosed with gastric epithelial neoplasia who underwent an endoscopic mucosal resection or submucosal dissection between 2004 and 2010 were included in this retrospective study. During the follow-up period (range, 4 to 14 years), disease recurrence was monitored, and tissue examinations were conducted for seven sets of microsatellite loci initially linked to the tumour suppressor gene locus. When H. pylori infection was identified, patients underwent eradication therapy. RESULTS: The patients (n = 120) were divided into three groups: H. pylori-negative with MSS, H. pylori-positive with MSS, and microsatellite instability (MSI). After H. pylori eradication, the rate of metachronous recurrence was significantly different in the MSI (28.2%) and MSS groups (3.7%, p < 0.01). The mean duration of recurrence was 77 months (range, 24 to 139) in the MSI group. There was no recurrence after eradication therapy in patients who were positive for H. pylori in the MSS group. CONCLUSION: H. pylori eradication could help prevent gastric cancer recurrence in patients with stable microsatellite loci. Careful, long-term monitoring is required in patients with unstable microsatellite loci.

Bridging the gap: Short structural variants in the genetics of anorexia nervosa.

Anorexia nervosa (AN) is a devastating disorder with evidence of underexplored heritability. Twin and family studies estimate heritability (h2 ) to be 57%-64%, and genome-wide association studies (GWAS) reveal significant genetic correlations with psychiatric and anthropometric traits and a total of nine genome-wide significant loci. Whether significantly associated single nucleotide polymorphisms identified by GWAS are causal or tag true causal variants, remains to be elucidated. We propose a novel method for bridging this knowledge gap by fine-mapping short structural variants (SSVs) in and around GWAS-identified loci. SSV fine-mapping of loci associated with complex disorders such as schizophrenia, amyotrophic lateral sclerosis, and Alzheimer's disease has uncovered genetic risk markers, phenotypic variability between patients, new pathological mechanisms, and potential therapeutic targets. We analyze previous investigations' methods and propose utilizing an evaluation algorithm to prioritize 10 SSVs for each of the top two AN GWAS-identified loci followed by Sanger sequencing and fragment analysis via capillary electrophoresis to characterize these SSVs for case/control association studies. Success of previous SSV analyses in complex disorders and effective utilization of similar methodologies supports our proposed method. Furthermore, the structural and spatial properties of the 10 SSVs identified for each of the top two AN GWAS-associated loci, cell adhesion molecule 1 (CADM1) and NCK interacting protein with SH3 domain (NCKIPSD), are similar to previous studies. We propose SSV fine-mapping of AN-associated loci will identify causal genetic architecture. Deepening understandings of AN may lead to novel therapeutic targets and subsequently increase quality-of-life for individuals living with the illness. PUBLIC SIGNIFICANCE STATEMENT: Anorexia nervosa is a severe and complex illness, arising from a combination of environmental and genetic factors. Recent studies estimate the contribution of genetic variability; however, the specific DNA sequences and how they contribute remain unknown. We present a novel approach, arguing that the genetic variant class, short structural variants, could answer this knowledge gap and allow development of biologically targeted therapeutics, improving quality-of-life and patient outcomes for affected individuals.

Endometrial Cancer Characteristics and Risk of Recurrence.

OBJECTIVES: To describe clinicopathologic characteristics and survival outcomes of endometrial adenocarcinomas stratified by mismatch repair (MMR) status. METHODS: Single-institution, retrospective study of all women with endometrioid adenocarcinomas treated from January 2012 through December 2017. Patients were categorized into one of three groups based on MMR testing: intact MMR expression (MMR+), probable MMR mutation (MMR-), or MLH1 hypermethylation (hMLH1+). Demographics, pathologic characteristics, recurrence rates, and survival differences were analyzed. RESULTS: In total, 316 women were included in the analysis: 235 (74.4%) patients in the MMR+ group, 10 (3.1%) in the MMR- group, and 71 (22.5%) in the hMLH1+ group. Patients with hMLH1+ were significantly older, exhibited higher-grade histology and presence of lymphovascular space invasion, and were more likely to have received adjuvant treatment. The early stage hMLH1+ patients were more likely to recur (15.3% hMLH1+ vs 2.3% MMR+ vs 12.5% MMR-, P < .001). Hypermethylation remained a significant predictor of recurrence in multivariable analysis (odds ratio, 5.09; 95% confidence interval [CI], 1.54-16.86; P = .008). Recurrence-free survival was significantly reduced in early stage hMLH1+ (hazard ratio, 7.40; 95% CI, 2.80-21.62; P < .001). CONCLUSIONS: Women with hMLH1+ endometrial cancer have worse prognostic features and recur more frequently, even in patients traditionally considered low risk for recurrence.

Antisense oligonucleotide and adjuvant exercise therapy reverse fatigue in old mice with myotonic dystrophy.

Patients with myotonic dystrophy type 1 (DM1) identify chronic fatigue as the most debilitating symptom, which manifests in part as prolonged recovery after exercise. Clinical features of DM1 result from pathogenic gain-of-function activity of transcripts containing an expanded microsatellite CUG repeat (CUGexp). In DM1 mice, therapies targeting the CUGexp transcripts correct the molecular phenotype, reverse myotonia, and improve muscle pathology. However, the effect of targeted molecular therapies on fatigue in DM1 is unknown. Here, we use two mouse models of DM1, age-matched wild-type controls, an exercise-activity assay, electrical impedance myography, and therapeutic antisense oligonucleotides (ASOs) to show that exaggerated exercise-induced fatigue progresses with age, is unrelated to muscle fiber size, and persists despite correction of the molecular phenotype for 3 months. In old DM1 mice, ASO treatment combined with an exercise training regimen consisting of treadmill walking 30 min per day 6 days per week for 3 months reverse all measures of fatigue. Exercise training without ASO therapy improves some measures of fatigue without correction of the molecular pathology. Our results highlight a key limitation of ASO monotherapy for this clinically important feature and support the development of moderate-intensity exercise as an adjuvant for targeted molecular therapies of DM1.

Partial hydatidiform moles with unclear histopathological profile - importance of genetic diagnostics.

OBJECTIVE: The aim of the study was the genetic characterization of a set of cases with an unclear morphological profile of the placental tissue suspected of a partial hydatidiform mole. PATIENTS AND METHODS: This work presents the results of a genetic analysis of a group of 10 patients with various clinical manifestations of reproductive loss, where a partial hydatidiform mole was suspected on the basis of a histopathological examination. The composition of the genome of the products of conception was determined by short tandem repeats (STR) genotyping using a commercial kit;Devyser Compact v3 (Devyser). RESULTS AND CONCLUSIONS: Out of 10 analyzed cases, five had diandric monogynic triploid genome, characteristic for a partial mole. Aneuploidies of chromosomes 13, 18, 21, X and Y were excluded in four cases and Pataus syndrome was dia-gnosed in one case. In the case of an unclear histopathological profile, consultative DNA analysis (ideally STR genotyping) can significantly help the pathologist in the differential dia-gnosis of a partial mole. The histopathological profile of a partial hydatidiform mole may be in some cases incomplete and unclear, especially in the early weeks of gestation, which can lead to false negativity of the examination. On the other hand, other pathologies, for example aneuploides or digynic triploidy, may produce a histopathological profile similar to a partial mole, which leads to false positivity. Accurate dia-gnosis of a partial hydatidiform mole using molecular genetic methods contributes to the determination of adequate dispensary care for patients.

Twins from different fathers: A heteropaternal superfecundation case report in Colombia / Gemelos de diferentes padres: un caso de superfecundación heteropaternal en Colombia

Abstract: Heteropaternal superfecundation is an extremely rare phenomenon that occurs when a second ova released during the same menstrual cycle is additionally fertilized by the sperm cells of a different man in separate sexual intercourse. In August, 2018, the Grupo de Genética de Poblaciones e Identificación at Universidad Nacional de Colombia received a request to establish the paternity of a pair of male twins with genetic markers. The following analyses were performed: amelogenin gene, autosomal short tandem repeat (STR), and Y-STR analyses by means of human identification commercial kits, paternity index, and the probability of paternity calculation and interpretation. A paternity index of 2.5134E+7 and a probability of paternity of 99.9999% for twin 2 were obtained while 14 out of 17 Y-chromosome markers and 14 out of 21 autosomal short tandem repeats were excluded for twin 1. The results indicated that the twins have different biological fathers. Although heteropaternal superfecundation is rarely observed among humans given its low frequency, in paternity disputes for dizygotic twins it is mandatory to demand the presence of the two twins in the testing to avoid wrong conclusions.

Resumen: La superfecundación heteropaternal es un fenómeno extremadamente raro que se produce cuando un segundo óvulo, liberado durante el mismo ciclo menstrual, es fertilizado por un espermatozoide de un hombre diferente en relaciones sexuales separadas. En agosto de 2018, el Grupo de Genética de Poblaciones e Identificación de la Universidad Nacional de Colombia recibió una solicitud para establecer la paternidad mediante marcadores genéticos de un par de mellizos varones, en quienes se hizo el análisis del gen de amelogenina, el análisis de repeticiones cortas en tándem (Short Tandem Repeats, STR) autosómicas y del cromosoma Y (Y-STR) mediante kits comerciales de identificación humana y cálculos e interpretación del índice de paternidad y probabilidad de paternidad. Se obtuvo un índice de paternidad de 2,5134E+7 y una probabilidad de paternidad de 99,9999 % para el gemelo 2, en tanto que en el gemelo 1 se excluyeron 14 de los 17 marcadores del cromosoma Y y 14 de los 21 sistemas STR autosómicos evaluados. Los resultados indicaron que los gemelos tienen diferentes padres biológicos. A pesar de que la superfecundación heteropaternal rara vez se observa en humanos debido a su baja frecuencia, en las disputas de paternidad para los gemelos dicigóticos, es obligatorio exigir en la prueba la presencia de los dos gemelos para evitar conclusiones incorrectas.

Survival of microsatellite-stable endometrioid endometrial cancer patients after minimally invasive surgery: An analysis of the Cancer Genome Atlas data.

OBJECTIVE: This study aims to investigate the survival impact of minimally invasive surgery on endometrial cancer (EC) patients with different histology and microsatellite status. METHODS: This is a retrospective study based on the Cancer Genome Atlas (TCGA) data. 519 eligible EC patients were divided into four subgroups according to histology and microsatellite status. Kaplan-Meier survival analyses were conducted in all patients and four subgroups to compare the survival outcome after two surgeries (open vs. minimally invasive). Propensity score matching and propensity score covariate adjustment models were used to control confounders. To establish survival prediction models for EC patients, multivariate stepwise Cox regressions were conducted. RESULTS: Among the eligible patients, 318 (61.3%) received open surgery and 201 (38.7%) received minimally invasive surgery. Overall survival was similar between the two groups (p = 0.33), but the latter showed significantly shorter recurrence-free survival (RFS) (p = 0.005). Subgroup analyses revealed the survival influence of surgical approach was only significant in microsatellite-stable (MSS) endometrioid EC patients. These results were verified by Kaplan-Meier survival analyses after propensity score matching and propensity score covariate adjustment models. Finally, the survival influence of multiple clinicopathological factors was analyzed. After stepwise Cox regressions, minimally invasive surgery was found to be independent risk factor for shorter RFS of all patients (hazard ratio [HR] = 2.038, 95% confidence interval [CI] 1.111-3.741, p = 0.02) and MSS patients (HR = 2.449, 95% CI 1.064-5.639, p = 0.04). CONCLUSIONS: Minimally invasive surgery is associated with more rapid recurrence in MSS endometrioid EC patients, thus indicating the necessity of microsatellite testing for guiding EC surgery.

Forensic parameters and allele frequency distributions of 16 STR in a Paraguayan population.

Paraguay is a Latin American country located in the central zone of South America. There is no official data on the ethnic composition of its population. The European colonization and the wars through which the country crossed were fundamental for its current genetic composition. Here, we analyzed sixteen short tandem repeats (STRs) used in the CODIS system in 259 Paraguayan individuals.

Segmental Duplications as a Complement Strategy to Short Tandem Repeats in the Prenatal Diagnosis of Down Syndrome.

BACKGROUND: Quantitative fluorescence-polymerase chain reaction (QF-PCR) is an inexpensive and accurate method for the prenatal diagnosis of aneuploidies that applies short tandem repeats (STRs) as a chromosome-specific marker. Despite its apparent advantages, QF-PCR is not applicable in all cases due to the presence of uninformative STRs. This study was carried out to investigate the efficiency of a method based on applying segmental duplications (SDs) in conjunction with STRs as an alternative to stand-alone STR-based QF-PCR for the diagnosis of Down syndrome. METHODS: Fifty amniotic fluid samples from pregnant women carrying Down syndrome fetuses, 9 amniotic fluid samples with 1 or without any informative STR marker (inconclusive), and 100 normal samples were selected from Shiraz, Iran, between October 2015 and December 2016. Analysis was done using an in-house STR-SD-based multiplex QF-PCR and the results were compared. Statistical analysis was performed using MedCalc, version 14. RESULTS: All the normal, Down syndrome, and inconclusive samples were accurately identified by the STR-SD-based multiplex QF-PCR, yielding 100% sensitivity and 100% specificity. Karyotype analysis confirmed all the cases with normal or trisomic results. CONCLUSION: The STR-SD-based multiplex QF-PCR correctly identified all the normal and trisomy 21 samples regardless of the absence of informative STR markers. The STR-SD-based multiplex QF-PCR is a feasible and particularly useful assay in populations with a high prevalence of homozygote STR markers.

Radiomics-based prediction of microsatellite instability in colorectal cancer at initial computed tomography evaluation.

PURPOSE: To predict microsatellite instability (MSI) status of colon cancer on preoperative CT imaging using radiomic analysis. METHODS: This retrospective study involved radiomic analysis of preoperative CT imaging of patients who underwent resection of stage II-III colon cancer from 2004 to 2012. A radiologist blinded to MSI status manually segmented the tumor region on CT images. 254 Intensity-based radiomic features were extracted from the tumor region. Three prediction models were developed with (1) only clinical features, (2) only radiomic features, and (3) "combined" clinical and radiomic features. Patients were randomly separated into training (n = 139) and test (n = 59) sets. The model was constructed from training data only; the test set was reserved for validation only. Model performance was evaluated using AUC, sensitivity, specificity, PPV, and NPV. RESULTS: Of the total 198 patients, 134 (68%) patients had microsatellite stable tumors and 64 (32%) patients had MSI tumors. The combined model performed slightly better than the other models, predicting MSI with an AUC of 0.80 for the training set and 0.79 for the test set (specificity = 96.8% and 92.5%, respectively), whereas the model with only clinical features achieved an AUC of 0.74 and the model with only radiomic features achieved an AUC of 0.76. The model with clinical features alone had the lowest specificity (70%) compared with the model with radiomic features alone (95%) and the combined model (92.5%). CONCLUSIONS: Preoperative prediction of MSI status via radiomic analysis of preoperative CT adds specificity to clinical assessment and could contribute to personalized treatment selection.

A potential role of extended simple sequence repeats in competing endogenous RNA crosstalk.

MicroRNA (miRNA)-mediated crosstalk between coding and non-coding RNAs of various types is known as the competing endogenous RNA (ceRNA) concept. Here, we propose that there is a specific variant of the ceRNA language that takes advantage of simple sequence repeat (SSR) wording. We applied bioinformatics tools to identify human transcripts that may be regarded as repeat-associated ceRNAs (raceRNAs). Multiple protein-coding transcripts, transcribed pseudogenes, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) showing this potential were identified, and numerous miRNAs were predicted to bind to SSRs. We propose that simple repeats expanded in various hereditary neurological diseases may act as sponges for miRNAs containing complementary repeats that would affect raceRNA crosstalk. Based on the representation of specific SSRs in transcripts, expression data for SSR-binding miRNAs and expression profiling data from patients, we determined that raceRNA crosstalk is most likely to be perturbed in the case of myotonic dystrophy type 1 (DM1) and type 2 (DM2).

GT-repeat extension in the IL11 promoter is associated with Hirschsprung's disease (HSCR).

Hirschsprung's disease (HSCR) is a congenital disease characterized by intestinal obstruction due to a defective intestinal neural system. Frequently, the disease is associated with an intestinal inflammation. The most common known underlying genetic alterations are in the RET gene but HSCR can also be caused by mutations in other genes that are responsible for the maturation and migration of intestinal neural cells. Recently, a study in an Asian population reported a significant association of several single nucleotide polymorphisms (SNPs) in the IL11 (interleukin 11) gene with HSCR. We further explored the possible association of genetic alterations in the IL11 gene with HSCR and HSCR subtypes in an unrelated Caucasian population. We used a targeted sequencing approach to identify a total of 32 SNPs covering the coding region of the IL11 gene including the proximal part of the promoter and relevant SNPs described in the previous study. Genotype frequencies were compared using additive genetic models in 103 HSCR patients and 128 healthy controls. We failed to observe any significant association of SNPs with HSCR. However, there was a suggestive evidence for an association of the length of a dinucleotide repeat in the IL11 promoter region with HSCR with an over-representation of >7 GT repeat subtypes (OR = 4.982 (1.448-17.040), p-value = 0.0111) in HSCR patients. A similar trend was further observed in a subgroup of patients with long-segment HSCR (L-HSCR). These findings need to be replicated in a well-powered study. Changes in IL11 expression may be a link to the intestinal inflammation frequently observed in patients with HSCR.

Altered levels of the splicing factor muscleblind modifies cerebral cortical function in mouse models of myotonic dystrophy.

Myotonic dystrophy (DM) is a progressive, multisystem disorder affecting skeletal muscle, heart, and central nervous system. In both DM1 and DM2, microsatellite expansions of CUG and CCUG RNA repeats, respectively, accumulate and disrupt functions of alternative splicing factors, including muscleblind (MBNL) proteins. Grey matter loss and white matter changes, including the corpus callosum, likely underlie cognitive and executive function deficits in DM patients. However, little is known how cerebral cortical circuitry changes in DM. Here, flavoprotein optical imaging was used to assess local and contralateral responses to intracortical motor cortex stimulation in DM-related mouse models. In control mice, brief train stimulation generated ipsilateral and contralateral homotopic fluorescence increases, the latter mediated by the corpus callosum. Single pulse stimulation produced an excitatory response with an inhibitory-like surround response mediated by GABAA receptors. In a mouse model of DM2 (Mbnl2 KO), we observed prolonged and increased responsiveness to train stimulation and loss of the inhibition from single pulse stimulation. Conversely, mice overexpressing human MBNL1 (MBNL1-OE) exhibited decreased contralateral response to train stimulation and reduction of inhibitory-like surround to single pulse stimulation. Therefore, altering levels of two key DM-associated splicing factors modifies functions of local cortical circuits and contralateral responses mediated through the corpus callosum.

[Clinical and genetic characteristics of facioscapulohumeral muscular dystrophy Landuzi-Dezherina type 1]. / Kliniko-geneticheskie kharakteristiki litse-plechelopatochnoi miodistrofii Landuzi-Dezherina tipa 1.

AIM: To describe clinical and genetic characteristics of patients from the Russian population with a variety of phenotypic variants of facioscapulohumeral muscular dystrophy Landuzi-Dezherina type 1 (FSHD 1). MATERIAL AND METHODS: The material for the study were blood samples of 16 patients from 15 unrelated families residing in the territory of the Russian Federation, between the ages of 6 to 66 years, with symptoms of FSHD. Diagnosis was based on genealogical data analysis, neurological examination, electroneuromyographic study, indicators of activity of creatine phosphokinase (CPK) in the blood serum and molecular genetic analysis of the results, aimed at the analysis of macrosatellite D4Z4 repeats on chromosome 4. RESULTS AND CONCLUSION: The study established the diagnosis of FSHD1 in 75% of patients. The correlation of the severity and phenotypic spectrum of FSHD1 with the age of onset was found. There was the significant clinical heterogeneity even among the 1st degree relatives in the same family. The correlation between macrosatellite D4Z4 repeats and clinical features of FSHD1 described previously in the literature was not observed.

Forensic DNA typing from teeth using demineralized root tips.

Teeth are widely used samples in forensic human genetic identification due to their persistence and practical sampling and processing. Their processing, however, has changed very little in the last 20 years, usually including powdering or pulverization of the tooth. The objective of this study was to present demineralized root tips as DNA sources while, at the same time, not involving powdering the samples or expensive equipment for teeth processing. One to five teeth from each of 20 unidentified human bodies recovered from midwest Brazil were analyzed. Whole teeth were demineralized in EDTA solution with daily solution change. After a maximum of approximately seven days, the final millimeters of the root tip was excised. This portion of the sample was used for DNA extraction through a conventional organic protocol. DNA quantification and STR amplification were performed using commercial kits followed by capillary electrophoresis on 3130 or 3500 genetic analyzers. For 60% of the unidentified bodies (12 of 20), a full genetic profile was obtained from the extraction of the first root tip. By the end of the analyses, full genetic profiles were obtained for 85% of the individuals studied, of which 80% were positively identified. This alternative low-tech approach for postmortem teeth processing is capable of extracting DNA in sufficient quantity and quality for forensic casework, showing that root tips are viable nuclear DNA sources even after demineralization.

A polymorphic GGC repeat in the NPAS2 gene and its association with melanoma.

Circadian clock regulation in mammals is controlled by feedback loops of a set of circadian genes. One of these circadian genes, NPAS2, encodes for a member of the bHLH-PAS class of transcription factors and is expressed in the forebrain and in some peripheral organs such as liver and skin. Other biological processes are also regulated by circadian genes. For example, NPAS2 is involved in cell proliferation, DNA damage repair and malignant transformation. Aberrant expression of clock genes has been previously observed in melanoma which led to our effort to sequence the NPAS2 promoter region in this cancer type. The NPAS2 putative promoter and 5' untranslated region of ninety-three melanoma patients and ninety-six control subjects were sequenced and several variants were identified. Among these is a novel microsatellite comprising a GGC repeat with different alleles ranging from 7 to 13 repeats located in the 5' untranslated exon. Homozygosity of an allele with nine repeats (9/9) was more prevalent in melanoma than in control subjects (22.6% and 13.5%, respectively, P: 0.0206) suggesting that some NPAS2 variants might contribute to melanoma susceptibility. Impact statement This report describes a variable microsatellite repeat sequence located in the 5' untranslated exon of NSPAS2, a gene encoding a clock transcription factor. Significantly, this study is the first to show that a variant copy number GGC repeat sequence in the NPAS2 clock gene associates with melanoma risk and which may be useful in the assessment of melanoma predisposition.