Author/Editor		Kunčnik, Vesna; Erjavec Škerget, Alenka; Stangler Herodež, Špela; Zagradišnik, Boris; Kokalj-Vokač, Nadja
Title		Odkrivanje sindroma fragilnega kromosoma X na osnovi tehnologije PCR pri moški populaciji iz severovzhodne Slovenije
Translated title		Detection of fragile X syndrome based on PCR technology in the male population of north-eastern Slovenia
Type		članek
Vol. and No.		Letnik 19, št. 1
Publication year		2012
Volume		str. 26-34
ISSN		1318-4423 - Slovenska pediatrija [Združenje pediatrov Slovenije]
Language		slv
Abstract		Uvod. Fragilni sindrom X (FXS) je najpogostejši vzrok za dedno obliko duševne manj razvitosti pri moških. Povzroča ga nestabilna pomnožitev trinukleotidnih ponovitev CGG v genu FMR1 na kromosomu X. Dokončna diagnoza FXS sloni na molekularni genetski analizi z metodo po Southernu, ki pa je zahtevna in dolgotrajna. V prispevku predstavljamo strategijo testiranja pri sumu na prisotnost FXS na osnovi testa z verižno reakcijo s polimerazo (PCR), ki je izključitvene narave, vendar je učinkovito vodilo pri odločitvah o nadaljnjem testiranju z metodo po Southernu. Predstavljamo rezultate retrospektivno opravljene analize na skupini moških preiskovancev iz severovzhodne Slovenije. Bolniki in metode. Retrospektivna študija je bila izvedena na 104 vzorcih genomske DNA preiskovancev moškega spola, ki so bili obravnavani v genetskem laboratoriju z napotitvenimi diagnozami: sum na FXS, nepojasnjena umska manj razvitost ter displastični znaki z avtizmom ali brez njega. Pri izbranih preiskovancih genetskega vzroka njihovih težav nismo odkrili. S tehniko PCR in agarozno elektroforezo smo določali prisotnost oz. odsotnost normalnega števila ponovitev tripleta CGG v regiji FMR1. Rezultati. Od 104 vzorcev smo bili s tehniko PCR uspešni pri 99 vzorcih. Pri petih vzorcih od 104 (4,81%) zaradi slabe kakovosti DNA rezultata nismo mogli podati. Prisotnost normalnega števila tripletov CGG smo dokazali pri 98 preiskovancih,pri enem preiskovancu od 99 (1,01%) pa smo postavili sum na FXS. Z metodo po Southernu smo diagnozo FXS tudi potrdili. Zaključki. Predstavljena metodologija na osnovi PCR je primerna kot preliminarni test za izključitev FXS pri preiskovancih moškega spola. Prisotnost polne mutacije smo našli pri 1,01% moških preiskovancev, pri katerih smo postavili sum na FXS.Background. Fragile X syndrome (FXS) is the most common cause of inherited mental retardation in males. It's caused by an unstable expansion of a trinucleotide CGG repeat in the FMR1 gene on chromosome X. The definitive diagnosis of FXS is based on molecular genetic analysis, using the Southern blot tehnique, which is a demanting and time-consuming tehnique. In this study we present a diagnostic strategy based on PCR assay, designed as an exclusion test for detection of the FMR1 mutation. We present the results of a retrospective analysis in agroup of male subjects from NE Slovenia. Methods. We present a retrospective study of 104 male subjects with the following referral diagnoses: suspected FXS,unexplained mental retardation or dysplastic signs with/without autism. The cause of their disability had not been revealed by previous diagnostic tests. We performed PCR analysis of genomic DNA extracted from the peripheral blood of subjects. Using the PCR technique and agarose electrophoresis we determined the presence/absence of the normal number of repeats of the CGG triplet in the FMR1 region. Results. The PCR method was successful in 99 of 104 subjects. In five of the 104 samples (4,81%) no results could be obtained because of bad DNA quality. The presence of normal CGG sequence variations was detected in 98 subjects. In one subject (1,01%, 1/99) we established the suspicion of FXS, which was subsequently confirmed by Southern blot analysis. Conclusions. The presented methodology based on PCR assay is suitable as a preliminary test to exclude FXS in male subjects. Using this approach we detected the full mutation in 1.01% of male subjects with suspected FXS.
Descriptors		Fragile X Syndrome Fragilni X sindrom X Chromosome Kromosom X Mental Retardation Duševna manjrazvitost Reverse Transcriptase Polymerase Chain Reaction Verižna reakcija s polimerazo Diagnosis Genetics Diagnostika Genetika Abnormalities Nepravilnosti