Title UTJECAJ DOBNE STAROSTI RODITELJA NA POJAVNOST SINDROMA DOWN
Title (english) The influence of parental age on the incidence of Down syndrome
Author Tea Petrović
Mentor Tatijana Zemunik (mentor)
Committee member Slavica Kozina (predsjednik povjerenstva)
Committee member Ljubica Žunić (član povjerenstva)
Committee member Tatijana Zemunik (član povjerenstva)
Granter University of Split (University Department of Health Studies) Split
Defense date and country 2014-07-09, Croatia
Scientific / art field, discipline and subdiscipline BIOMEDICINE AND HEALTHCARE Basic Medical Sciences Medical Biochemistry
Abstract Sindrom Down (SD) je najčešća kromosomopatija i većina djece rođena sa SD imaju u svim svojim stanicama po jedan krmosom (broj 21) više, stoga se taj sindrom naziva još i trisomija 21 kromosoma. Uzrok poremećaja broja kromosoma je nerazdvajanje istog para kromosoma u gametma majke. Jedini dokazani uzrok nerazdvajanja kromosoma je dob majke i potvrđena je češća pojava SD u majki iznad 35 godina. Iz toga zaključujemo da nastanak aneuploidije raste sa starošću majke, a najčešće je uzrokovana nerazdvajanjem kromosoma.
SD uzrokuje pogrešan prijenos kromosoma tijekom stanične diobe spolnih stanica, tako da se u jednosj stanici nađe višak cijelog ili dijela kromosoma. Najčešće nastaje u jajnoj stanici prije oplodnje, dok se manjem broju slučajeva pojavljuje u spermiju. Tada stanice ne sadrže 46 kromosoma, već 47 kromosoma.
Djeca sa SD imaju karakterističan izgled: koso položene oči, brazdu četvrtog prsta, udubljeni korijen nosa, nosnice uvrnute prema gore. U osoba sa SD javlja se srednja do blaga mentalna retardacija, usporen razvoj govora, kratak vijek života koji je posljedica srčanih mana.
Kako bi se na vrijeme otkrile moguće kromosomopatije trudnicama se preporučava rani rekombinantni probir koji se radi između 11. i 14. tjedna trudnoće. Rani rekombinantni probir najefikasnija je metoda za detektiranje do 90% trudnoća sa SD i drugim kromosomskim greškama. Za razliku od ranog rekombinantnog probira koji se radi u prvom tromjesečju, u drugom tromjesečju rade se testovi probira, tzv. „double“ i „triple“. To su testovi koji se određuju iz krvi majke i imaju manju mogućnost otkrivana oko 50-70 % .
U samoj prenatalnoj dijagnostici trisomije 21 koriste se još invazine i neinvazine metode. U invazivne metode se ubrajaju amniocenteza i CVS. Danas u prenatalnoj dijagnostici rabe se i razne molekularne metode kao što je flourescentna in situ hibridizacija (FISH) i kvantitativne lančane reakcije polimezare(Q-PSR) koje su vrlo brze, a imaju visoku osjetljivost i specifičnost.
Utvrđivanjem prenatalnog rizika za razvoj SD temelji se na dobrovoljnom pristanku roditelja. Roditeljima se upoznati s mogućim neinvazivnim i invazivnim metodama samog probira i dijagnostike, te oni trebaju dati pisani pristanak.
Abstract (english) SD or Down syndrome is the most common chromosomal disorder and most of the children born with SD have extra chromosome ( number 21) in all of their cells, so the syndrome is also called trisomy 21. The cause of the disorder is a nonseparation of the same pair of chromosomes in mother's gametes. The only proven cause of the nonseparation is mother's age and it is proven that SD occurs far more often in mothers aged above 35 years. Therefore we can see that the incidence of aneuploidy rises with mother's age and is caused by the nonseparation of the chromosomes.
SD causes a wrong transmission of the chromosomes during meiosis which results in one cell having a part or an entire extra chromosome. It mainly occurs in egg cell before fertilization, but can also occur in sperm cell in less cases. At the point, cells do not contain 46 but 47 chromosomes.
Children with SD have characteristic appearance: slanted eyes, indentation of the fourth finger, sunken nasal root, twisted nose. Typical syndromes are also: mild to moderate intellectual disability, delayed speech development, shortened life expectancy as a consequence of heart defects.
In order to detect possible chromosomal disorders on time, pregnant women are advised to take the early recombinant screening test during the eleventh and fourteenth week of pregnancy. The early recombinant screening test is the most efficient method for detecting 90 % pregnancies with SD and other chromosomal disorders. Unlike early screening tests which are done in the first trimester, 'double' and 'triple' tests are done in the second trimester. Those tests are determined from mother's blood and are less reliable, around 50-70%.
Prenatal diagnosis of the trisomy 21 also uses some other invasive and noninvasive methods. The invasive ones include amniocentesis and CVS. Prenatal diagnosis nowadays also uses molecular methods such as flourescent in situ hybridization (FISH) and quantitative polymerase chain reaction ( Q-PCR) which are fast and have great sensitivity and specificity.
Prenatal risk determinatation for SD development is based upon voluntary parental consent. Parents are introduced with the possible noninvasive and invasive methods of the sole test and diagnosis, and they should give their written consent.
Since 2012, in The Croatian Register of Persons with Disabilities 1.446 people have been diagnosed with SD. The SD frequency is equal between both sexes. The largest number of registered persons, a staggering 58,2% belong to a younger age group (0-19 years).
7. LITERATURA
Keywords
sindrom Down
kromosomopatija
prenatalna dijagnostika
Keywords (english)
Down syndrome
chromosomal disorder
prenatal diagnosis
Language croatian
URN:NBN urn:nbn:hr:176:497266
Study programme Title: Medical Laboratory Diagnostics (university/undergraduate) Study programme type: university Study level: undergraduate Academic / professional title: sveučilišni prvostupnik/prvostupnica (baccalaureus/baccalaurea) medicinska laboratorijska dijagnostika (sveučilišni prvostupnik/prvostupnica (baccalaureus/baccalaurea) medicinska laboratorijska dijagnostika)
Type of resource Text
File origin Born digital
Access conditions Open access
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Created on 2018-09-04 08:33:14