Konstantina Kosma

Distribution of serum lipids and lipoproteins in patients with beta thalassaemia major; an epidemiological study in young adults from Greece

BackgroundBeta-thalassaemia major (b-TM) has been defined as a combination of chronic hemolytic anemia, iron storage disease and myocarditis, and it has been associated with premature death especially due to heart failure. To the best of our knowledge the status of blood lipids in these patients has rarely been investigated. Thus, we assessed the levels of lipids and lipoproteins in a sample of cardiovascular disease free adult men and women with b-TM.MethodsDuring 2003 we enrolled 192 consecutive patients with b-TM that visited our Institution for routine examinations. The Institution is considered the major reference center for b-TM in Greece. Of the 192 patients, 88 were men (25 ± 6 years old) and 104 women (26 ± 6 years old). Fasting blood lipid levels were measured in all participants.ResultsData analysis revealed that 4% of men and 2% of women had total serum cholesterol levels > 200 mg/dl, and 11% of men and 17% of women had triglyceride levels > 150 mg/dl. In addition, mean HDL cholesterol levels were 32 ± 11 mg/dl in men and 38 ± 10 mg/dl in women, lipoprotein-a levels were 8.3 ± 9 mg/dl in men and 8.8 ± 9 mg/dl in women, apolipoprotein-A1 levels were 111 ± 17 mg/dl in men and 123 ± 29 mg/dl in women, and apolipoprotein-B levels were 60 ± 20 mg/dl in men and 59 ± 14 mg/dl in women. Total-to-HDL cholesterol ratios were 3.7 ± 1.2 and 3.8 ± 1.5 in men and women, respectively.ConclusionsThe majority of the patients had blood lipid levels (by the exception of HDL-cholesterol) within the normal range, and consequently the prevalence of lipid and lipoprotein abnormalities was much lower as compared to the general population of the same age. Interestingly, is that the total – to HDL cholesterol ratio was high in our patients, and may underline the importance of this index for the prognosis of future cardiac events in these patients.

Microdeletion and microduplication 17q21.31 plus an additional CNV, in patients with intellectual disability, identified by array-CGH.

The recognition of the 17q21.31 microdeletion and microduplication syndrome has been facilitated by high resolution oligonucleotide array comparative genome hybridization technology (aCGH). Molecular analysis of the 17q21.31 microdeletion/duplication syndrome demonstrated a critical region involving at least six genes, including STH and MAPT. The 17q21.31 microdeletion syndrome has an incidence of 1 in 16,000 births, while the microduplication 17q21.31 has been reported so far in only five patients. In general, phenotypes associated with 17q21.31 microduplication seem to be milder than those associated with the microdeletion. Here, we present four patients who have been referred for genetic evaluation by clinical geneticists due to developmental delay and minor congenital abnormalities. Previous standard karyotypes were negative, while aCGH analysis revealed three patients with 17q21.31 microdeletion and one with the respective microduplication, being the sixth reported case so far. Most importantly one of the microdeletion cases involves only partial MAPT gene deletion while leaving the STH gene intact. Two of our patients, one with the 17q21.31 microdeletion and another with the respective microduplication, carried additional clinically relevant microdeletions (del Xq21.31 and del 15q11.2, respectively), possibly modifying their phenotype.

Array comparative genomic hybridization as a clinical diagnostic tool in syndromic and nonsyndromic congenital heart disease.

Background:Congenital heart diseases (CHDs) are often associated with other congenital anomalies, dysmorphic features, and developmental delay, and only a few cases of chromosomal abnormalities are detected by conventional cytogenetic techniques. The microarray comparative genomic hybridization (CGH) analysis allows the identification of submicroscopic genomic rearrangements.Methods:During the past 3 y, 55 of 330 patients referred for array CGH had CHD of unknown etiology plus at least one additional indication of abnormal chromosomal phenotype. High-resolution 1 × 244K or 4 × 180K Agilent arrays were used in this study (average resolution 7–13 kb).Results:Copy-number variations were detected in 37 of 55 patients, and in 29 of 37 patients there were genes that have been associated with CHD. All 37 patients had at least one additional phenotypic abnormality: 30 of 37 had one or more other congenital anomalies, 23 of 37 had dysmorphic features, 16 of 37 had intellectual disability, 13 of 37 had abnormal magnetic resonance imaging, 10 of 37 had hypotonia, and 7 of 37 had seizures. In 9 of 55 patients, unexpected genomic rearrangements in relation to their phenotype were identified.Conclusion:In patients with CHD and at least one additional indication of abnormal chromosomal phenotype, array CGH analysis could detect possible submicroscopic chromosomal abnormalities and provide proper genetic counseling.

Recurrent copy number variations as risk factors for autism spectrum disorders: analysis of the clinical implications

Chromosomal microarray analysis (CMA) is currently considered a first‐tier diagnostic assay for the investigation of autism spectrum disorders (ASD), developmental delay and intellectual disability of unknown etiology. High‐resolution arrays were utilized for the identification of copy number variations (CNVs) in 195 ASD patients of Greek origin (126 males, 69 females). CMA resulted in the detection of 65 CNVs, excluding the known polymorphic copy number polymorphisms also found in the Database of Genomic Variants, for 51/195 patients (26.1%). Parental DNA testing in 20/51 patients revealed that 17 CNVs were de novo, 6 paternal and 3 of maternal origin. The majority of the 65 CNVs were deletions (66.1%), of which 5 on the X‐chromosome while the duplications, of which 7 on the X‐chromosome, were rarer (22/65, 33.8%). Fifty‐one CNVs from a total of 65, reported for our cohort of ASD patients, were of diagnostic significance and well described in the literature while 14 CNVs (8 losses, 6 gains) were characterized as variants of unknown significance and need further investigation. Among the 51 patients, 39 carried one CNV, 10 carried two CNVs and 2 carried three CNVs. The use of CMA, its clinical validity and utility was assessed.

Microduplication 3q13.2q13.31 identified in a male with dysmorphic features and multiple congenital anomalies

Constitutional microdeletions affecting 3q13.2q13.31 are rare and attempts for genotype–phenotype correlations have only recently been made in a cohort of 28 patients. The major phenotypic features of this rare syndrome are hypotonia, developmental delay, and facial anomalies. In this study, we report on a male infant with a novel reciprocal 3.671 Mb microduplication at the genomic region 3q13.2q13.31 associated with dysmorphic features and multiple congenital anomalies. The current patient was investigated by high‐resolution array comparative genomic hybridization (aCGH). This is the first report of a microduplication 3q13.2q13.31 that shares a lot of common clinical features with those carrying the microdeletion. The 3q13.2q13.31 duplicated region in our patient contains nine dosage sensitive genes, amongst them the genes ATG3, CCDC80, KIAA2018, NAA50, ZDHHC23, DRD3, ZBTB20, GAP43, LSAMP. As it is the case for many other well‐described reciprocal deletion/duplication syndromes, some have very different clinical features (Williams–Beuren deletion syndrome, WBS/WBS triplication) [Somerville et al. (2005); N Engl J Med 353:1694–1701], while others share similar phenotypic features (22q11.2 microdeletion/microduplication) [Portnoi (2009); Eur J Med Genet 52:88–93]. In conclusion, we describe the main phenotypic features of a possibly novel microduplication 3q13.2q13.31 syndrome. Additionally five of the dosage‐sensitive genes and BOC gene are suggested to be responsible for the main phenotypic features. Evaluation of multiple patients with the microduplication is needed for full delineation of this syndrome.

Genomic screening of ABCA4 and array CGH analysis underline the genetic variability of Greek patients with inherited retinal diseases.

Background Retinal dystrophies are a clinically and genetically heterogeneous group of disorders which affect more than two million people worldwide. The present study focused on the role of the ABCA4 gene in the pathogenesis of hereditary retinal dystrophies (autosomal recessive Stargardt disease, autosomal recessive cone-rod dystrophy, and autosomal recessive retinitis pigmentosa) in patients of Greek origin. Materials and methods Our cohort included 26 unrelated patients and their first degree healthy relatives. The ABCA4 mutation screening involved Sanger sequencing of all exons and flanking regions. Evaluation of novel variants included sequencing of control samples, family segregation analysis and characterization by in silico prediction tools. Twenty five patients were also screened for copy number variations by array-comparative genomic hybridization. Results Excluding known disease-causing mutations and polymorphisms, two novel variants were identified in coding and non-coding regions of ABCA4. Array-CGH analysis revealed two partial deletions of USH2A and MYO3A in two patients with nonsyndromic autosomal recessive retinitis pigmentosa. Conclusions The ABCA4 mutation spectrum in Greek patients differs from other populations. Bioinformatic tools, segregation analysis along with clinical data from the patients seemed to be crucial for the evaluation of genetic variants and particularly for the discrimination between causative and non-causative variants.

Compound heterozygosity of a paternal submicroscopic deletion and a maternal missense mutation in POR gene: Antley-bixler syndrome phenotype in three sibling fetuses

BACKGROUND Antley-Bixler syndrome (ABS) is an exceptionally rare craniosynostosis syndrome that can be accompanied by disordered steroidogenesis, and is mainly caused by mutations in the POR gene, inherited in an autosomal recessive manner. Here we report the prenatal and postmortem findings of three sibling fetuses with ABS as a result of compound heterozygosity of a paternal submicroscopic deletion and a maternal missense mutation in the POR gene. METHODS Prenatal ultrasound and postmortem examination were performed in three sibling fetuses with termination of pregnancy at 22, 23, and 17 weeks of gestation, respectively. Molecular analysis of fetus 2 and 3 included (a) bidirectional sequencing of exon 8 of the POR gene after amplification of the specific locus by polymerase chain reaction, to detect single nucleotide variants (SNVs) and (b) high resolution comparative genomic hybridization (CGH) positive single nucleotide polymorphism array CGH (aCGH) analysis to detect copy number variants (CNVs), copy neutral areas of loss of heterozygosity and uniparental disomy. RESULTS The diagnosis of ABS was suggested by the postmortem examination findings. The combination of the POR gene molecular analysis and aCGH revealed a compound heterozygous genotype of a maternal SNV (p.A287P) and a paternal CNV (NC_000007.13:g.(?_75608488)_(75615534_?)del). CONCLUSION To the best of our knowledge, these sibling fetuses add to the few reported cases of ABS, caused by a combination of a SNV and a CNV in the POR gene. The detailed description of the pathologic and radiographic findings of second trimester fetuses affected with ABS adds novel knowledge concerning the early ABS phenotype, in lack of previous relevant reports. Birth Defects Research (Part A) 106:536-541, 2016.

Phenotypic expression of a spectrum of Neurofibromatosis Type 1 (NF1) mutations identified through NGS and MLPA

Neurofibromatosis Type 1 (NF1) is caused by mutations of the NF1 gene. The aim of this study was to identify the genetic causes underlying the disease, attempt possible phenotype/genotype correlations and add to the NF1 mutation spectrum. A screening protocol based on genomic DNA was established in 168 patients, encompassing sequencing of all coding exons and adjoining introns using a custom targeted next generation sequencing protocol and subsequent confirmation of findings with Sanger sequencing. MLPA was used to detect deletions/duplications and positive findings were confirmed by RNA analysis. All novel findings were evaluated according to ACMG Standards and guidelines for the interpretation of sequence variants with the aid of in-silico bioinformatic tools and family segregation analysis. A germline variant was identified in 145 patients (86%). In total 49 known and 70 novel variants in coding and non-coding regions were identified. Seven patients carried whole or partial gene deletions. NF1 patients, present with high phenotypic variability even in cases where the same germline disease causing variant has been identified. Our findings will contribute to a better knowledge of the genetic causes and the phenotypic expression related to the disease.

UBE3A, c.1347_1348delGA: a mutation in question.

*Corresponding author: Christalena Sofocleous, Molecular Biologist, Department of Medical Genetics, School of Medicine, Athens University, “Aghia Sophia” Children’s Hospital, Thivon and Livadias street, 11527 Athens, Greece, Phone: +302 1074 67470, Phone/Fax: +302 1077 95553, E-mail: csofokl@med.uoa.gr; and Research Institute for the Study of Genetic and Malignant Diseases in Childhood, “Aghia Sophia” Children’s Hospital, Athens Greece Evmorfia Tzagkaraki, Konstantina Kosma, Emmanuel Kanavakis and Sofia Kitsiou-Tzeli: Department of Medical Genetics, School of Medicine, Athens University, “Aghia Sophia” Children’s Hospital, Athens, Greece Letter to the Editor

An unusual case of cat-eye syndrome phenotype and extragonadal mature teratoma: Review of the literature†‡

BACKGROUND Cat-Eye syndrome (CES) with teratoma has not been previously reported. We present the clinical and molecular findings of a 9-month-old girl with features of CES and also a palpable midline neck mass proved to be an extragonadal mature teratoma, additionally characterized by array comparative genomic hybridization (aCGH). RESULTS High resolution oligonucleotide-based aCGH confirmed that the supernumerary marker chromosome (SMC) derived from chromosome 22, as was indicated by molecular cytogenetic analysis with fluorescence in situ hybridization (FISH). Additionally, aCGH clarified the size, breakpoints, and gene content of the duplication (dup 22q11.1q11.21; size:1.6 Mb; breakpoints: 15,438,946-17,041,773; hg18). The teratoma tissue was also tested with aCGH, in which the CES duplication was not found, but the analysis revealed three aberrations: del Xp22.3 (108,864-2788,689; 2.7 Mb hg18), dup Yp11.2 (6688,491-7340,982; 0.65 Mb, hg18), and dup Yq11.2q11.23 (12,570,853-27,177,133; 14.61 Mb, hg18). These results indicated 46 XY (male) karyotype of the teratoma tissue, making this the second report of mature extragonadal teratoma in a female neonate, probably deriving from an included dizygotic twin of opposite sex (fetus in fetu). CONCLUSIONS Our findings extend the phenotypic spectrum of CES syndrome, a disorder with clinical variability, pointing out specific dosage-sensitive genes that might contribute to specific phenotypic features.