Is cervical swab an efficient method for developing a new noninvasive prenatal diagnostic test for numerical and structural chromosome anomalies?

Background/aim: Prenatal diagnosis is vital to obtain healthy generation for risky pregnancies. There have been several approaches, some of which are routinely applied in clinics to evaluate the possible prenatal deficiencies and/or diseases. In the present study, we aimed to isolate the fetal cells from endocervical samples and try to identify possible anomalies which were proved by Amniocentesis (AS) and chorionic villus sampling (CVS) methods. Materials and methods: Endoservical specimens were collected from 100 pregnant women. Cells were separated in parallel by fluorescence-activated cell sorting (FACS) and magnetic-activated cell sorting (MACS) using human leukocyte antigen (HLA) G233 and placental alkaline phosphatase (PLAP) antibodies. CMA (comprehensive meta-analysis) were carried out and male fetuses were confirmed with Sex determining region Y (SRY) amplification. Results: The percent of HLA G233 and placental and placental alkaline phosphatase (PLAP) positive cells were 4.55% and 84.59%, respectively. The percent of cells positive for both markers was 14.75%. CMA analyses were not informative. (SRY) was amplified in 67% of the samples. Conclusion: However, the success rate of the both cell sorting and scanning of DNA anomalies by aCGH and/or RT-PCR was limited, preventing the applicability of this proposal in the clinics. Still, the success of the proposed method depends on the development of the novel fetal cell-specific antibodies and the improvements in the sorting systems.

Expression of the syncytin-1 and syncytin-2 genes in the trophoblastic tissue of the early pregnancy losses with normal and abnormal karyotypes.

BACKGROUND: Syncytin-1 and syncytin-2 which are endogenous retroviral genes products play a great role in syncytialization during trophoblast differentiation in normal placental tissues. In aneuploidic placentas due to the low level of pregnancy-induced hormones an alteration was occurred in the syncytialization process, while in the presence of cytogenetically abnormal karyotype the effect of syncytin gene expression levels on syncytialization process and in occured to spontaneous abortions is not clear. To reveal this, we investigated in syncytin-1 and syncytin-2 genes expression levels of chromosomally abnormal and normal trophophoblastic tissues and we also discussed the effect of the syncytin gene expression levels to the occurense of the spontaneous abortion. MATERIAL AND METHODS: To each one of the trophoblastic cells; cultivation, harvesting, banding, and analysis were performed and the chromosomes were classified according to the presence of abnormality and normal XY constitution. To exclude the maternal decidual cell contamination, female karyotyped abortion materials were omitted in control group. The patient group consisted of thirty six placental tissues including trisomy 16 (n = 10), triploidy (n = 9), monosomy X (n = 9), trisomy 21 (n = 5) and trisomy 7 (n = 3). The control group was consisting twenty placental tissues with XY karyotypes. The some part of the dissected frozen trophoblastic cells were used for RNA isolation and were proceeded to the determination of the expression levels of syncytin-1 and syncytin-2 genes by single-step Real Time PCR. The cDNAs were obtained by probes used in the same PCR stages. The sequence analysis of the syncytin-1 and syncytin-2 genes were performed, and read by the usage of the FinchTV 1.4.0 program. RESULTS: Between the expression levels of syncytin-1 and syncytin-2 genes were statistically difference in the patients and controls. There was a difference (p < 0.0001) between trisomy 7 and other patient groups and controls, regarding to the expression of syncytin-1 gene. Numerous mutations in the syncytin-1 and syncytin-2 genes (on the expression sites) were detected, and the mutation rate was higher in the syncytin-1 gene compared to the syncytin-2 gene in the patient and in the control groups (p < 0.001). CONCLUSION: The results of the study indicate that the expression of the syncytin-2 genes could be altered in the presence of chromosomally abnormal trophoblastic tissues, and these could lead to the loss of pregnancy due to the insufficient syncytialization. In sum, the current research has value for the further studies covering the mechanisms of trophoblast cell fusion, and syncytiotrophoblast regeneration, and thus the pathophysiology of human placental development in the presence of genomic anomaly.

Microdeletion and mutation analysis of the SHOX gene in patients with idiopathic short stature with FISH and sequencing

Background/aim: The aim of this study was to investigate the prevalence of the microdeletions and mutations of the SHOX gene in children with idiopathic short stature (ISS) by the usage of fluorescence in situ hybridization (FISH) and direct sequencing technique. Materials and methods: Thirty-seven children referred to our clinic because of short stature were classified as having ISS after clinical examination. Chromosome analyses, FISH analysis of the SHOX gene, and direct sequencing of the coding exons of SHOX , through the second to the sixth exon, in 24 of the 37 patients were also performed. Results: All children had normal karyotypes and the SHOX gene region was found to be intact in all. No mutation was detected in the exonic sequences and exon/intron boundaries of the SHOX gene in 24 children analyzed. Conclusion: No mutation was detected in the exonic sequences and exon/intron boundaries of the SHOX gene and this indicated that the prevalence of the SHOX mutations can differ according to the selection criteria, used methods, sample size, and population.

Confirmation of the prenatal mosaic trisomy 2 via fetal USG and cytogenetic analyses.

Mosaic trisomy 2 in second-trimester amniocentesis is a very rare aneuploidy. The outcome of the pregnancies is quite variable, spontaneous abortions are frequent. A 37-year old woman underwent amniocentesis at 18 weeks of gestation because of abnormal serum screening with single umbilical artery (SUA) and cardiac dextroposition in fetal ultrasound (USG), and the cytogenetic result was 47,XX,+2[12]/46,XX[73]. Repeated amniocentesis and simultaneously cordocentesis at 21 weeks of gestation were ended with the analyses of the same mosaic aneuploidy. In addition to SUA and cardiac dextroposition, diaphragmatic hernia was detected in USG examination that was confirmed by fetal magnetic resonance imaging. The pregnancy was terminated at 22 weeks of gestation. Prenatal diagnosis of two or more cells with trisomy 2 at amniocentesis with USG findings should alert the physician for clinically significant aneuploidy and the presence of low-level trisomy 2 mosaicism at amniocentesis should be confirmed.

Chromosomal-array analysis reveals partial 11q duplication and partial 12p deletion in a mildly affected case.

Partial trisomy 11q is a rare syndrome and may be observed due to an intra-chromosomal duplication or an inter-chromosomal insertion. The deletions of the short arm of chromosome 12 are also uncommon structural aberrations. Only a small fraction of structural chromosome anomalies are related to the unbalanced progeny of balanced translocation carrier parents. We here report on a 10-month-old baby boy who shows a very mild phenotype related to unique chromosomal abnormality, partial trisomy of 11q, and partial monosomy of 12p, due to the maternal balanced reciprocal translocation (11;12). The proband showed a 49.64 Mb duplication of 11q14.1-q25 and 0.44 Mb deletion of 12p13.33 in chromosomal array analysis. Since it is known that the duplications may cause a milder phenotype than deletions. Dysmorphic facial features, minor cardiac anomalies, respiratory distress, central nervous system anomalies, and psychomotor delay observed in the patient was similar to the reported pure 11q duplication cases, while behavioral problems observed in pure monosomy 12p cases could not be evaluated due to the young age of the patient. Phenotype-genotype correlation will be discussed in view of all the reported pure partial 11q trisomies and pure partial 12p deletion cases.

Molecular karyotyping of an isolated partial trisomy 11q patient with additional findings.

Isolated partial duplication of the long arm of chromosome 11 is very rare. The main features are dysmorphic facial features, pre/postnatal growth retardation, speech delay, mental retardation, hypotonia, microcephaly, and cardiac, vertebral, limb and genital anomalies. In this case, we report a patient with partial trisomy of 11q13.5→qter due to a de novo rearrangement consisting of the whole X chromosome and part of chromosome 11; 46,X,der(X)(Xqter→Xp22.33::11q13.5→11qter). Additional findings were a separated clavicle, lacrimal duct stenosis and prenatally detected renal hypoplasia. SNP array results revealed a duplication between 11q13.5 and 11qter, measuring 58 Mb, from nucleotide 76,601,607 to 134,926,021. As a result, molecular karyotyping could be performed in such cases in order to establish a definite phenotype-genotype correlation using conventional or molecular cytogenetics techniques.

The importance of systematic genetic approach to familial schizophrenia cases and discussion of cryptic mosaic X chromosome aneuploidies in schizophrenia pathogenesis.

Abstract Objective. The aim of this study is to contribute to the understanding of schizophrenia genetics by using efficient algorithmic examination techniques including dysmorphic examination, karyotyping, and Fluoresence in situ hybridization (FISH). Methods. In this study we have investigated 20 familial schizophrenia patients from Turkey who had an affected first-degree relative. Dysmorphic examination of the schizophrenia cases and their relatives have been performed. High resolution banding (HRB), specific centromeric, subtelomeric and 22q11.2 region FISH probes were used for genotyping of patients. Results. Dysmorphic examination revealed ear, palate, nose, columella anomalies, and obesity in contributing patients, and the pale skin was noticed. The medical histories and clinical findings of two schizophrenia twins were almost identical. HRB study demonstrated the presence of 46,XX[55]/47,XXX[4]/48,XXXX[1] constitution in a paranoid schizophrenia case and 46,XX[67]/45,X[5] karyotype in her mother. FISH studies aiming subtelomeric chromosomal regions revealed no rearrangements and 22q11.2 regions were intact in all of the patients. Conclusions. The parental gonadal mosaicism lying at the origin of the mitotic aneuploidy may be the reason for mosaic X chromosome aneuploidies in our mother-daughter schizophrenia couple. Mosaic X chromosome aneuploidies may accompany schizophrenia cases and may contribute to pathogenesis of familial schizophrenia.

A case with a ring chromosome 22.

Ring chromosome 22, a rare cytogenetic finding, was first described in 1968, and since then about 60 patients have been reported. We describe a new patient with ring chromosome 22 syndrome and discuss the common features of the previously reported cases. Our patient had the major features of this syndrome including mental retardation, hypotonia, motor delay, microcephaly, dysplastic large ears, lack of speech, and hyperactivity disorder. Magnetic resonance imaging findings also revealed an arachnoid cyst, found in the posterior cerebellum. In patients with ring chromosome 22, variable clinical manifestations may be seen due to the size of lost sequences near the telomere. By fluorescent in situ hybridization (FISH) technique, LSI DiGeorge/VCFS/ ARSA locus-specific probes are used to detect deleted sequences. We found that 22q11.2 regions were intact on both chromosomes 22, but 22q13.3 (Arylsulfatase A; ARSA region) was absent in the ring chromosome. As far as we know this is the first reported Turkish patient in the literature.