www.ksmf.org/arhimed   arhimed@ksmf.org   [5/10/2025 7:22:24 PM] http://www.ksmf.org/arhimed/poglej.asp?id=36 Pogostnost sindroma fragilnega X pri slovenskih otrocih z duševno manjrazvitostjo Avtor: Irena Kumelj, Barbara Mihevc Mentor: doc. dr. Borut Peterlin, dr. med. Izhodišca. Sindrom fragilni X(A) ali FRAX(A) je najpogostejša dedna oblika duševne manjrazvitosti in je posledica pomnožitve trinukleotidnih ponovitev CGG v genu FMR1 na kromosomu X. Ta pomnožitev vodi v inaktivacijo gena FMR1, ki se klinicno kaže kot Martin-Bellov fenotip. Primere sindroma FRAX so v drugih populacijah ugotovili v razlicnih skupinah duševno manjrazvitih, med drugim v šolah s prilagojenim programom. V Sloveniji nimamo podatkov o pogostnosti sindroma FRAX, zato smo z našo raziskavo želeli oceniti njegovo pogostnost v slovenskih šolah s prilagojenim programom. Pricakovali smo, da bomo v teh šolah ugotovili delež otrok s sindromom FRAX. Metode. V raziskavo smo zajeli 100 otrok, 58 deckov in 42 deklic, iz šole s prilagojenim programom, pri katerih vzrok duševne manjrazvitosti ni bil znan. V casu raziskave so bili stari od 7 do 18 let, povprecna starost je bila 13 let s standardno deviacijo 2,45. Za preiskovance smo dolocili vrednost kratkega klinicnega presejalnega testa za sindrom fragilni X in analizirali njihovo DNA z metodo PCR in z metodo po Southernu. Z metodo PCR in z metodo po Southernu smo direktno ugotavljali pomnožitev CGG trinukleotidnih ponovitev v genu FMR1. Rezultati. Med 100 preiskovanci, ki že na kratkem klinicnem presejalnem testu niso bili sumljivi za sindrom FRAX, s specificno molekularno diagnostiko nismo odkrili primerov tega sindroma. Zakljucki. Zakljucimo lahko, da sindrom FRAX ni pomemben vzrok duševne manjrazvitosti v slovenskih šolah s prilagojenim programom. Menimo, da je vecji del otrok s tem sindromom med otroki s težjo stopnjo duševne manjrazvitosti. «» [Abstract / English version] The frequency of fragile X syndrome among slovene children with mental retardation Author: Irena Kumelj, Barbara Mihevc Mentor: doc. dr. Borut Peterlin, dr. med. Introduction. Fragile X syndrome is the most common inherited form of familial mental retardation. It results from a CGG trinucleotide expansion in the FMR1 gene, which leads to its inactivation and Martin-Bell phenotype. In different populations there was found FRAX syndrome among different groups of mentally retarded children, including children attending the special education schools. In Slovenia there has not been any reports on the prevalence of FRAX syndrome. The aim of our study was to assess the frequency of FRAX syndrome among children attending the special education schools. We expected to find a certain percentage of the children with FRAX syndrome. Methods. In our study we ascertained 100 children, 58 boys and 42 girls, 7-18 years of age; mean 13 years (SD ± 2,45), attending the special education schools, with previously unknown origin of mental retardation. The children were assessed by the clinical screening score for the fragile X syndrome and their DNA was analysed by PCR assay and by Southern blot analysis. By PCR assay and by Southern blot analysis, we directly searched for the amplification of CGG repeats in the FMR1 gene. Results. Among 100 children who had not been suspected for the FRAX syndrome after the clinical screening score, none tested positive for the FRAX syndrome by the specific molecular diagnosis. Conclusion. We may conclude that FRAX syndrome is not a significant cause of mental retardation among Slovene children attending special education schools. We believe that there are more children with the FRAX syndrome among children with more severe mental retardation.