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Search Results: 1 - 10 of 276 matches for " Emmanouil Manolakos "
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Correction: Characterization of a prenatally assessed de novo supernumerary minute ring chromosome 20 in a phenotypically normal male
Sofia Kitsiou-Tzeli, Emmanouil Manolakos, Magdalini Lagou, Katerina Anagnostopoulou, Maria Kontodiou, Nadezda Kosyakova, Elisabeth Ewers, Anja Weise, Antonios Garas, Sandro Orru, Thomas Liehr, Aikaterini Metaxotou
Molecular Cytogenetics , 2009, DOI: 10.1186/1755-8166-2-8
Abstract: The authors declare that they have no competing interests.SKT conceived of the study and participated in its design and coordination. EM performed the cytogenetic studies and participated in its design and coordination. ML and MK participated in the cytogenetic analysis. NK, EE and AW participated in the molecular cytogenetic analysis. AG performed the ultrasonography of the pregnant woman. SO and KA performed the molecular analysis for uniparental disomy. TL was responsible for the molecular cytogenetic studies and participated in the drafting of the manuscript. AM participated in the design and coordination of the study and participated in the drafting of the manuscript. All authors read and approved the final manuscript.
Prenatal diagnosis of Wolf-Hirschhorn syndrome confirmed by comparative genomic hybridization array: report of two cases and review of the literature
Stavros Sifakis, Emmanouil Manolakos, Annalisa Vetro, Dimitra Kappou, Panagiotis Peitsidis, Maria Kontodiou, Antonios Garas, Nikolaos Vrachnis, Anastasia Konstandinidou, Orsetta Zuffardi, Sandro Orru, Ioannis Papoulidis
Molecular Cytogenetics , 2012, DOI: 10.1186/1755-8166-5-12
Abstract: Wolf-Hirschhorn syndrome (WHS; OMIM 194190) [1], also known as deletion 4p and 4p-syndrome, is a well known clinical condition caused by a partial deletion of the short arm of chromosome 4. WHS was first (and independently) described by Wolf et al. (1965) and Hirschhorn et al. (1965) [2,3]; thereafter, more than 180 documented cases have been published in the literature, most of them diagnosed postnatally. The prevalence of WHS is reported to be around 1/50.000 live births with a 2:1 female/male ratio; however, this is likely underestimated because of under-recognition or misdiagnosis of affected individuals [4,5].In the majority of cases, WHS is caused by a "pure" deletion of 4p16 with no other cytogenetic abnormality while in the remaining cases, there could be a more complicated cytogenetic finding such as chromosome 4 ring, 4p- mosaicism, or a derivative chromosome 4 resulting from either a de novo or inherited unbalanced translocation [5,6]. The complexity of the WHS-associated basic genomic changes is an important factor explaining phenotypic variability; though the typical clinical features include growth restriction of prenatal onset, profound psychomotor retardation, seizures, skeletal abnormalities, and a distinctive facial appearance [7]. Associated major malformations with variable incidence (30-70%) are mainly related to midline fusion defects such as midline scalp defects, agenesis of corpus callosum, cleft lip/palate, heart defects, and urinary tract malformations [7,8].Most prenatally diagnosed cases of WHS are associated with large 4p deletions identified by conventional chromosome analysis while the widespread clinical use of novel high-resolution molecular techniques such as array comparative genomic hybridization (a-CGH) increased the detection rate of submicroscopic chromosomal aberrations that could also lead to a WHS phenotype. Herein, we present two WHS cases suspected upon abnormal signs in prenatal ultrasonography, diagnosed with convention
Detailed molecular and clinical investigation of a child with a partial deletion of chromosome 11 (Jacobsen syndrome)
Emmanouil Manolakos, Sandro Orru, Rosita Neroutsou, Konstantinos Kefalas, Eirini Louizou, Ioannis Papoulidis, Loretta Thomaidis, Panagiotis Peitsidis, Sotirios Sotiriou, George Kitsos, Panagiota Tsoplou, Michael B Petersen, Aikaterini Metaxotou
Molecular Cytogenetics , 2009, DOI: 10.1186/1755-8166-2-26
Abstract: We report a 7.5 years old boy presenting with speech development delay, hearing impairment and abnormal platelet function. High resolution SNP oligonucleotide microarray analysis revealed a terminal deletion of 11.4 Mb in size, in the area 11q24.1-11qter. This specific deletion encompasses around 170 genes. Other molecular techniques such as fluorescence in situ hybridization and multiplex ligation-dependent probe amplification were used to confirm the array-result.Our results suggest that the identification and detailed analysis of similar patients with abnormal platelet function and otherwise mild clinical features will contribute to identification of more patients with 11q deletion and JBS.Jacobsen syndrome (JBS) is a rare inherited disorder with variable phenotypic expression and partial deletion of chromosome 11q. To date more than 200 cases were reported, with an estimated prevalence of 1/100,000 births [1]. Clinical manifestations of JBS typically include developmental and mental retardation, facial dysmorphism, congenital heart defects, and thrombocytopenia [2-5]. In more detail typical JBS features include short stature, mental retardation, congenital heart defects, thrombocytopenia and characteristic facial dysmorphism consisting of skull deformities, ocular hypertelorism, ptosis, downward slanting palpebral fissures, epicanthal folds, flat nasal bridge, short nose with flat philtrum and thin upper lip, v-shaped mouth and small and low set ears. The neck is short, the hands show cutaneous syndactyly, the fingers are thin with flat finger pads and the feet are stubby, flat with clinodactylous toes. Malformations of kidneys are present in 13% of cases, gastrointestinal tract problems in 18%, abnormal genitalia in 36%, central nervous system and skeletal dysplasias in 14%. Abnormal platelet function, thrombocytopenia or pancytopenia is affecting at least 88% of cases and is usually present from birth [6,7]. About 20% of the children die during the first two y
Complex chromosome rearrangement in a child with microcephaly, dysmorphic facial features and mosaicism for a terminal deletion del(18)(q21.32-qter) investigated by FISH and array-CGH: Case report
Emmanouil Manolakos, Nadezda Kosyakova, Loreta Thomaidis, Rozita Neroutsou, Anja Weise, Markos Mihalatos, Sandro Orru, Haris Kokotas, George Kitsos, Thomas Liehr, Michael B Petersen
Molecular Cytogenetics , 2008, DOI: 10.1186/1755-8166-1-24
Abstract: Cases involving partial deletions or duplications of chromosome 18 are well documented in the literature. The 18q- syndrome constitutes one of the frequent autosomal deletion syndromes in man, with more than 100 patients reported [1]. The syndrome includes moderate intrauterine growth retardation, moderate mental retardation, and a specific pattern of dysmorphisms and anomalies [1]. Mosaicism for a deleted chromosome 18 has been described in a few patients with mostly the full clinical picture of the 18q- syndrome. Here, we report a patient with an unusual mosaic karyotype consisting of cells with normal karyotype and others with a terminal deletion of one chromosome 18 and the other chromosome 18 having an interstitial duplication.The patient, a 7-year-old boy, was the second child of unrelated, healthy parents. He was born with cesarean section after a full term pregnancy. His birth weight was 2,850 kg, length 45 cm and head circumference (HC) 32 cm. His perinatal period was uneventful. His developmental milestones were delayed as he sat independently at the age of 13 months and walked at the age of 27 months. His first words were spoken at the age of 2 years and 5 months.He was a sociable child, with microcephaly (HC = 50.5 cm, 2nd percentile), and dysmorphic facial features such as: maxillary hypoplasia, epicanthal folds, upslanting palpebral fissures, long eyelashes, and hypertelorism. His ears were prominent and dysmorphic and he had a high arched palate. His weight was 17 kg (25th percentile) and his height 120 cm (50th percentile).His non-verbal skills were equivalent to a 4 years and 4 months level and his language skills were equivalent to a 30 months level. According to Griffiths Scales Bailey's Scales of Mental Development (2nd Edition), his General Developmental Quotient (GDQ) was 52 with Performance DQ = 59 and Language DQ = 45. His behavior was normal for his developmental age. He was severely hypertonic but without asymmetry.Heart auscultation was no
Characterization of a prenatally assessed de novo supernumerary minute ring chromosome 20 in a phenotypically normal male
Sofia Kitsiou-Tzeli, Emmanouil Manolakos, Magdalini Lagou, Maria Kontodiou, Nadezda Kosyakova, Elisabeth Ewers, Anja Weise, Antonios Garas, Sandro Orru, Thomas Liehr, Aikaterini Metaxotou
Molecular Cytogenetics , 2009, DOI: 10.1186/1755-8166-2-1
Abstract: Here we describe a 3 months old male child with normal pre- and postnatal development and with a de novo ring supernumerary marker chromosome in amniocytes cultures. Using new fluorescence in situ hybridization (FISH) techniques, three distinguishable sSMCs (cryptic mosaicism), all derived from chromosome 20, were observed, including ring and minute chromosomes. This heterogeneity was impossible to detect by the conventional G-banding technique or conventional FISH technique that were used before the application of new FISH techniques (subcentromere-specific multicolor-FISH [subcenM-FISH]) and a probe, specific for the 20p12.2 band. The sSMC present in 25% of the cells was present as r(20)(::p12.2~12.3->q11.1::)[5]/r(20;20)(::p12.1->q11.1::q11.1 >p12.1::)[2]/min(20;20)(:p12.1->q11.1::q11.1->p12.1:)[1]. The final karyotype was 47,XY,+r(20)[25%]/46,XY[75%].We emphasize the importance of application of molecular cytogenetics in a prenatally diagnostic laboratory and description of more cases to enable a better genetic counseling and risk evaluation.Small supernumerary marker chromosomes (sSMCs) are structurally abnormal chromosomes that cannot be identified or characterized unambiguously by conventional cytogenetics alone, and they are generally equal in size or smaller than chromosome 20 at the same metaphase spread [1]. The heterogeneous group of sSMCs presents serious genetic counseling problems, especially if they are present de novo and diagnosed prenatally. The incidence of sSMCs has been estimated at 0.075% in prenatal diagnoses [2]. Identification of an sSMC only by cytogenetics is almost impossible. For this reason fluorescence in situ hybridization (FISH) is most valuable and has been successfully applied for the determination of the chromosomal origin of sSMCs [3].Most marker chromosomes are derived from the short arms and pericentric regions of the acrocentric chromosomes, while the occurrence of an additional derivative chromosome 20 is rare. No common phe
Combined 22q11.1-q11.21 deletion with 15q11.2-q13.3 duplication identified by array-CGH in a 6 years old boy
Emmanouil Manolakos, Catherine Sarri, Annalisa Vetro, Konstantinos Kefalas, Eleni Leze, Christalena Sofocleus, George Kitsos, Konstantina Merou, Haris Kokotas, Anna Papadopoulou, Achilleas Attilakos, Michael B Petersen, Sofia Kitsiou-Tzeli
Molecular Cytogenetics , 2011, DOI: 10.1186/1755-8166-4-11
Abstract: The above definition contains an error and should instead be written as follows: 46,XY.ish der(15)(15pter->15q11.2::22q11.2->22qter)t(15;22)(q11.2;q11.2)mat(TUPLE-,TBX1-).
Combined 22q11.1-q11.21 deletion with 15q11.2-q13.3 duplication identified by array-CGH in a 6 years old boy
Emmanouil Manolakos, Catherine Sarri, Annalisa Vetro, Konstantinos Kefalas, Eleni Leze, Christalena Sofocleus, George Kitsos, Konstantina Merou, Haris Kokotas, Anna Papadopoulou, Achilleas Attilakos, Michael B Petersen, Sofia Kitsiou-Tzeli
Molecular Cytogenetics , 2011, DOI: 10.1186/1755-8166-4-6
Abstract: Here we report a 6-year-old boy presenting growth retardation, dysmorphic features and who exhibited learning difficulties. Fluorescence in situ hybridization (FISH) analysis of the proband revealed a deletion of DiGeorge Syndrome critical region (TUPLE). Array-CGH analysis revealed an interstitial duplication of 12 Mb in size in the area 15q11.2-q13.3, combined with a 3.2 Mb deletion at region 22q11.1-q11.21. FISH analysis in the mother showed a cryptic balanced translocation between chromosome 15 and chromosome 22 (not evident by classic karyotyping).The clinical manifestations could be related to both syndromes and the importance of array-CGH analysis in cases of unexplained developmental delay is emphasized. The present case further demonstrates how molecular cytogenetic techniques applied in the parents were necessary for the genetic counseling of the family.DiGeorge syndrome and Velo-Cardio-Facial syndrome (DGS/VCFS) are the result of deletions of chromosome 22q11.2 in over 90% of cases [1]. The cardinal features and symptoms are cellular immunodeficiency due to thymus hypo or aplasia, hypocalcemia because of absence of the parathyroid, congenital heart defect with high mortality and morbidity, and typical faces [2]. The prevalence of the syndrome is estimated (probably underestimated) to approximately 1:4,500 and represents one of the commonest genetic diseases [3].The 4 Mb 15q11-q13 region, containing three biallelically expressed genes, which encode receptor subunits for the inhibitory neurotransmitter gamma-aminobutyric acid (GABRB3, GABRA5 and GABRG3), is prone to structural rearrangements [4,5]. Duplications of this region occurring on the maternal chromosome, have been associated with a complex neurobehavioral phenotype that often includes language delay, seizures and autism (OMIM# 608636) [6-11,4].Clayton-Smith et al (1993) had initially reported a patient with a 15q11-q13 duplication including the Angelman syndrome critical region (ASCR), who had atax
The use of array-CGH in a cohort of Greek children with developmental delay
Emmanouil Manolakos, Annalisa Vetro, Konstantinos Kefalas, Stamatia-Maria Rapti, Eirini Louizou, Antonios Garas, George Kitsos, Lefteris Vasileiadis, Panagiota Tsoplou, Makarios Eleftheriades, Panagiotis Peitsidis, Sandro Orru, Thomas Liehr, Michael B Petersen, Loretta Thomaidis
Molecular Cytogenetics , 2010, DOI: 10.1186/1755-8166-3-22
Abstract: Fourteen CNVs were detected in the studied patients. In nine patients (11%) the chromosomal aberrations were inherited from one of the parents. One patients showed two duplications, a 550 kb duplication in 3p14.1 inherited from the father and a ~1.1 Mb duplication in (22)(q13.1q13.2) inherited from the mother. Although both parents were phenotypically normal, it cannot be excluded that the dual duplication is causative for the patient's clinical profile including dysmorphic features and severe developmental delay. Furthermore, three de novo clinically significant CNVs were detected (3.7%). There was a ~6 Mb triplication of 18q21.1 in a girl 5 years of age with moderate MR and mild dysmorphic features and a ~4.8 Mb duplication at (10)(q11.1q11.21) in a 2 years old boy with severe MR, multiple congenital anomalies, severe central hypotonia, and ataxia. Finally, in a 3 year-old girl with microcephaly and severe hypotonia a deletion in (2)(q31.2q31.3) of about ~3.9 Mb was discovered. All CNVs were confirmed by Fluorescence in situ hybridization (FISH). For the remaining 9 patients the detected CNVs (inherited duplications or deletions of 80 kb to 800 kb in size) were probably not associated with the clinical findings.Genomic microarrays have within the recent years proven to be a highly useful tool in the investigation of unexplained MR. The cohorts reported so far agree on an around 11% diagnostic yield of clinically significant CNVs in patients with unexplained MR. Various publicly available databases have been created for the interpretation of identified CNVs and parents are analyzed in case a rare CNV is identified in the child. We have conducted a study of Greek patients with unexplained MR and confirmed the high diagnostic value of the previous studies. It is important that the technique becomes available also in less developed countries when the cost of consumables will be reduced.Mental retardation (MR) is a common disorder for which the genetic diagnosis in man
No input symbol should occur more frequently than 1-1/e
Gowtham Kumar,Alexandros Manolakos
Mathematics , 2012,
Abstract: Consider any discrete memoryless channel (DMC) with arbitrarily but finite input and output alphabets X, Y respectively. Then, for any capacity achieving input distribution all symbols occur less frequently than 1-1/e$. That is, \[ \max\limits_{x \in \mathcal{X}} P^*(x) < 1-\frac{1}{e} \] \noindent where $P^*(x)$ is a capacity achieving input distribution. Also, we provide sufficient conditions for which a discrete distribution can be a capacity achieving input distribution for some DMC channel. Lastly, we show that there is no similar restriction on the capacity achieving output distribution.
Kolmogorov Flow: Seven Decades of History  [PDF]
Emmanouil D. Fylladitakis
Journal of Applied Mathematics and Physics (JAMP) , 2018, DOI: 10.4236/jamp.2018.611187
Abstract: The Kolmogorov flow (k-flow) is generated by a stationary sinusoidal force that varies in space. This flow is rather academic since generating such a periodic forcing in an unbounded flow is difficult to appear in nature. Nevertheless, it allows for simple experimental measurements and for a fairly detailed analytical treatment. Although simple, the k-flow makes a good test case for investigating simultaneously inhomogeneous, sheared, and anisotropic features in a flow, and several studies concerning the stability, transition, and turbulence of the k-flow have been published. The present article reviews the most important published works incorporating the k-flow as a test-bed for studying fluid mechanics, testing numerical or experimental methods, or even studying the properties of the k-flow itself.
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