Current methods in prenatal diagnosis

Metode koje se primjenjuju u suvremenoj prenatalnoj dijagnostici mogu biti invazivne i neinvazivne. Uobičajene invazivne metode, poput amniocenteze i biopsije korionskih resica, primjenjuju se posljednjih tridesetak godina. Posljednjih dvadesetak godina intenzivno se razvijaju neinvazivne tehnike koje trebaju biti potpuno bezopasne, i za majku, a i za plod, te lako dostupne široj trudničkoj populaciji. U raduje dan pregled najčešće primjenjivanih rutinskih tehnika prenatalne dijagnostike te najnovija dostignuća u tom području, s naglaskom na mogućnosti primjene analize slobodne fetalne DNA iz krvne plazme majke.Current methods used for prenatal diagnosis can be invasive or noninvasive. Common invasive techniques, like amniocentesis or chorionic villus biopsy, have been used for the last thirty years. During the last twenty years, extensive work in development of noninvasive techniques has been done. General goal of noninvasive methods is to be completely safe and available to all pregnant women. In this review, most commonly used techniques of prenatal diagnosis as well as recent developments in the field are being presented, especially possible application of analysis of cell free fetal DNA from maternal plasma

Current methods in prenatal diagnosis

Metode koje se primjenjuju u suvremenoj prenatalnoj dijagnostici mogu biti invazivne i neinvazivne. Uobičajene invazivne metode, poput amniocenteze i biopsije korionskih resica, primjenjuju se posljednjih tridesetak godina. Posljednjih dvadesetak godina intenzivno se razvijaju neinvazivne tehnike koje trebaju biti potpuno bezopasne, i za majku, a i za plod, te lako dostupne široj trudničkoj populaciji. U raduje dan pregled najčešće primjenjivanih rutinskih tehnika prenatalne dijagnostike te najnovija dostignuća u tom području, s naglaskom na mogućnosti primjene analize slobodne fetalne DNA iz krvne plazme majke.Current methods used for prenatal diagnosis can be invasive or noninvasive. Common invasive techniques, like amniocentesis or chorionic villus biopsy, have been used for the last thirty years. During the last twenty years, extensive work in development of noninvasive techniques has been done. General goal of noninvasive methods is to be completely safe and available to all pregnant women. In this review, most commonly used techniques of prenatal diagnosis as well as recent developments in the field are being presented, especially possible application of analysis of cell free fetal DNA from maternal plasma

HEREDITARY HEMOCHROMATOSIS GENE MUTATIONS IN PATIENTS WITH MYOCARDIAL INFARCTION

Hereditary hemochromatosis (HH) is a disorder of iron accumulation in tissues, which is related to coronary heart diseases. Free radicals and reactive oxygen species, created because of iron deposition, promote oxidation of LDL cholesterol and could lead to the development of atherosclerosis. Studies have shown that HFE gene mutation carriers might be at higher risk of developing cardiovascular diseases compared with non-carriers. This study aimed to determine the frequency of HFE gene mutations in patients with myocardial infarction compared to a healthy group in eastern Slavonia. A retrospective case-control study was carried out on a population of 400 participants. In the first group there were 200 patients (114 males and 86 females) with myocardial infarction. The second group consisted of 200 controls (103 males and 97 females) without a history of cardiovascular diseases. All patients were genotyped for the three most common mutations of the HH in the HFE gene: C282Y, H63D, and S65C, by real-time PCR. The difference in the frequency of carriers of these mutations between the patients and the controls was not significant (C282Y: 4.5 vs. 8.1%; H63D: 19 vs. 24.5%; S65C: 3.5 versus 4%), and neither was the frequency and distribution of possible HFE gene genotypes and compound heterozygotes. There were no statistically significant associations of cardiovascular risk factors and HFE gene mutations in patients with myocardial infarction. In this study, no association was found between the HFE gene mutation for HH and myocardial infarction in the population of eastern Slavonia

Free DNA – new potential analyte in clinical laboratory diagnostics?

The existence of cell free DNA in the human circulatory system has been known since the 1950s, however, intensive research in this area has been conducted for the last ten years. This review paper brings a short overview of the existing literature concerning the cell free DNA research in various cli-nical fields and pathological states and considers the application possibilities of this new analyte in clinical laboratory diagnostics. At the moment, cell free DNA is most widely used for the purpose of non-invasive prenatal diagnosis of fetal sex or fetal RhD status. The recent discovery of epigenetic changes in placental/fetal DNA and the detection of fetal/placental-specific RNAs have made it possible to use this technology in all preg-nancies irrespective of the gender of the fetus. With the application of new techniques such as next generation sequencing, digital PCR and mass spectrometry, it is now possible to detect very small amounts of specific DNA in the presence of excess of other nonspecific nucleic acids. Second most probable application is in oncology, where detection and monitoring of tumors is now possible by the detection of tumor-derived nucleic acids. Third promising field for near future implementation of this analyte is transplantation medicine, where free DNA level could serve as a marker of transplant rejec-tion. Before any further utilization of this new biomarker, pre-analytical and analytical aspects of free DNA analysis remain to be standardized. In the field of noninvasive prenatal diagnosis, important ethical, legal and social questions remain to be discussed

HEREDITARY HEMOCHROMATOSIS GENE MUTATIONS IN PATIENTS WITH MYOCARDIAL INFARCTION

Hereditary hemochromatosis (HH) is a disorder of iron accumulation in tissues, which is related to coronary heart diseases. Free radicals and reactive oxygen species, created because of iron deposition, promote oxidation of LDL cholesterol and could lead to the development of atherosclerosis. Studies have shown that HFE gene mutation carriers might be at higher risk of developing cardiovascular diseases compared with non-carriers. This study aimed to determine the frequency of HFE gene mutations in patients with myocardial infarction compared to a healthy group in eastern Slavonia. A retrospective case-control study was carried out on a population of 400 participants. In the first group there were 200 patients (114 males and 86 females) with myocardial infarction. The second group consisted of 200 controls (103 males and 97 females) without a history of cardiovascular diseases. All patients were genotyped for the three most common mutations of the HH in the HFE gene: C282Y, H63D, and S65C, by real-time PCR. The difference in the frequency of carriers of these mutations between the patients and the controls was not significant (C282Y: 4.5 vs. 8.1%; H63D: 19 vs. 24.5%; S65C: 3.5 versus 4%), and neither was the frequency and distribution of possible HFE gene genotypes and compound heterozygotes. There were no statistically significant associations of cardiovascular risk factors and HFE gene mutations in patients with myocardial infarction. In this study, no association was found between the HFE gene mutation for HH and myocardial infarction in the population of eastern Slavonia

Prenatal Diagnosis of 18p Deletion and Isochromosome 18q Mosaicism in a Fetus with a Cystic Hygroma

Although, deletion of short arm of chromosome 18 is one of the most frequent autosomal terminal deletions, mosaic form of 18p deletion is infrequently observed. Furthermore, prenatally detected cases of 18p deletion and isochromosome 18q mosaicism are extremely rare. Herein, we present a case of del(18p)/i(18q) mosaicism, prenatally detected after chorionic villus sampling. A 37-year-old woman was referred for prenatal diagnosis because of fetal septated cystic hygroma measuring 4.3 mm. Cytogenetic analysis showed a mosaic 46,XX,del(18)(p11.2)/46,XX,i(18)(q10) karyotype in both, short- and long-term culture. Parents elected to terminate the pregnancy. Fetal mosaic karyotype was confirmed by chromosomal analysis of cultured skin fibroblasts. Molecular characterization of chromosome 18 structural aberrations was performed by fluorescence in situ hybridization (FISH). Considering variable ultrasound findings among cases with del(18p)/i(18q) mosaicism, we emphasized that first and second trimester ultrasound screening examinations for fetal malformations, followed by cytogenetic and molecular evaluations, are very important in the management of prenatally detected cases

Prenatal Diagnosis of 18p Deletion and Isochromosome 18q Mosaicism in a Fetus with a Cystic Hygroma

Although, deletion of short arm of chromosome 18 is one of the most frequent autosomal terminal deletions, mosaic form of 18p deletion is infrequently observed. Furthermore, prenatally detected cases of 18p deletion and isochromosome 18q mosaicism are extremely rare. Herein, we present a case of del(18p)/i(18q) mosaicism, prenatally detected after chorionic villus sampling. A 37-year-old woman was referred for prenatal diagnosis because of fetal septated cystic hygroma measuring 4.3 mm. Cytogenetic analysis showed a mosaic 46,XX,del(18)(p11.2)/46,XX,i(18)(q10) karyotype in both, short- and long-term culture. Parents elected to terminate the pregnancy. Fetal mosaic karyotype was confirmed by chromosomal analysis of cultured skin fibroblasts. Molecular characterization of chromosome 18 structural aberrations was performed by fluorescence in situ hybridization (FISH). Considering variable ultrasound findings among cases with del(18p)/i(18q) mosaicism, we emphasized that first and second trimester ultrasound screening examinations for fetal malformations, followed by cytogenetic and molecular evaluations, are very important in the management of prenatally detected cases

Partial Monosomy 2p and Partial Trisomy 4q due to Paternal Translocation t(2;4)(p25.1;q31.3)

Clinical features in patients with segmental aneuploidy often vary depending on the size of the chromosomal segment involved. Monosomy 2p is usually observed as a part of more complex syndromes among probands of balanced reciprocal translocation carriers. Patients with dup4q syndrome have variable clinical features, which are both related to the size of duplicated segment of the 4q and specific associated monosomy. Clinical findings of our patient were compatible with those previously reported in dup4q and del2p patients. Herein are presented the clinical and cytogenetic findings in a 4-year-old female with an unbalanced karyotype 46,XX,der(2)t(2;4)(p25.1;q31.3)pat. Clinical phenotypes of 2p;4q translocation cases are variable, because the involved breakpoints vary case-by-case. We also compare similarity of the clinical features of our proband and other patients carrying either duplication of the distal part of 4q and patients carrying a deletion of distal part of 2p as described in the literature. To our knowledge, this is the first case of partial trisomy 4q accompanied with partial monosomy 2p

De Novo Case of a Partial Trisomy 4p and a Partial Monosomy 8p

The extent of clinical expression in cases of segmental aneuploidy often varies depending on the size of the chromosomal region involved. Here we present clinical and cytogenetic findings in a 5-month old boy with a duplication of a chromosomal segment 4p16.1→4pter and a deletion of a chromosomal segment 8p23.1→8pter. His karyotype was determined by applying classical GTG banding and FISH method (WHCR region, centromere 4, centromere 8, telomere 8p) as 46,XY,der(8)t(4;8)(p16.1;p23.1).ish der(8)t(4;8)(D8S504-,WHCR+,D8Z2+)dn. Parents are not related and have normal karyotypes, indicating de novo origin. We have compared similarity of the clinical features in our proband to other patients carrying only a duplication of the distal part of 4p or a deletion of distal part of 8p or similar combination described in the literature

PROGINS Mutation of Progesterone Receptors and Its Role in Premature Birth – An Overview

Premature ( or preterm ) birth ( birth prior 37 weeks of gestation ) is big worldwide medical and socioeconomic problem. It percentage is 8-12% of total number of births, and apart from the increased mortality of newborns, it is also cause of increased morbidity in for it. worldwide, as far as some statistical reviewes say, 15 million of babies per year are preterm born. Despite the frequency, consequences and costs of premature delivery, very little has been done for preventing it, especially for preventing early premature deliveries. Etiology of premature labor is multifactorial, and includes pathophysiology, genetics and enviromental factors. Resent scientific researches, particulary in the field of human genomics, show that genetic factors, mostly present in genome of mother, contribute up to 40% variation in delivery time. It is belived that premature birth has same cascade of events like normal birth; just in this case it starts sooner. This process is controlled by series of hormonal effects between fetus, placenta and mother. One of the key signaling pathways in this series is progesterone one. PROGINS allele is progesterone receptor gene modification. It is built of 3 variants : V660L,H770H and alu insertion. Progesterone receptors with PROGINS mutation are less susceptible to progesteron activity, and it looks as the withdrawal of progesterone causes the beggining of birth cascade. +331G/A progesterone receptor mutation is newly discovered mutation. It is belived that this mutation leads to PR-a an PR-B receptor quantity disorder before delivery term. The aim of this review is to resume all recent aknowledgements about PROGINS and +331G/A mutation of progesterone receptor and see if there is the value of these genetic mutations in modulation of risk for preterm birth