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DETEKCIJA  IVSII-745 MUTACIJE U -GLOBINSKOM GENU

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DETECTION OF  IVSII-745 MUTATION IN THE -GLOBIN GENE

ANA SARID, 2. razred, Peta beogradska gimnazija Regionalni centar za talente Beograd II

Mentor: dr MILENA RADMILOVID, istraživač saradnik, ,,Institut za molekularnu genetiku i genetičko
inžinjerstvo”

REZIME

Talasemijski sindromi pripadaju grupi naslednih oboljenja koju odlikuje poremedena sinteza jednog ili više globinskih lanca koji
ulaze u sastav hemoglobina. Ova oboljenja se obično klasifikuju prema tipu globinskog lanca koji odsustvuje (0- i 0-talasemije)
ili je prisutan u smanjenim količinama (+- i +-talasemije). U slučaju +-talasemije, ispitivane u ovom radu, dolazi do sinteze
produženog -globinskog lanca kao posledica mutacije u drugom intronu -globinskog gena (+IVS II-745).

Cilj ovog rada je da se pronađe (detektuje) mutacija u -globinskom genu kod dvoje dece čiji je otac heterozigotni nosilac -
talasemije (ako je ima). Pošto je majka zdrava, verovatnoda da deca naslede mutiran gen od oca i postanu heterozigotni nosioci
mutacije je 50%.

Za detekciju mutacija u okviru -globinskog gena, u ovom radu korišdena je ARMS PCR metoda (Amplification Refractory
Mutation System, eng.). Ova vrsta PCR (Polymerase Chain Reaction, eng.) analize radi se u dve epruvete. U jednoj se umnožava
sekvenca gena gde se mutacija nalazi, dok se u drugoj umnožava ta ista sekvenca bez mutacije. Rezultate PCR reakcije videli smo
nakon elektroforeze i došli smo do zaključka da oba deteta imaju po jedan mutiran gen tj. da su nasledila -talasemiju od oca.

Pretpostavka koju smo doneli na osnovu hematoloških podataka pokazala se tačnom. Molekularna dijagnostika talasemijskih
sindroma veoma je važna zbog blagovremene terapije kojom bi se popravila klinička slika, tok i prognoza bolesti.

Ključne reči: mutacija, β-globinski gen, ARMS PCR, elektroforeza
SUMMARY

Thalassemia syndromes belong to a group of inherited disorders characterized by a defect in synthesis of globin chains that
hemoglobin is composed of. These disorders are classified acording to the type of globine chain who’s synthesis is absent (0- i
0-talasemije), or is severily reduced (+- i +-talasemije). In the case of +-thalassemia presented in this work, mutation in the
beta-globin gene (+IVS II-745) causes synthesis of an extended -globin chain.

The aim of this work was to analyze the presence of mutation in beta-globin gene in two children whose father is a heterozygot
carrier of beta-thalassemic mutation. Since mother is healthy, the possibility of children inheriting mutated gene from the father
and becoming heterozygous carriers is 50%.

For detection of the mutations within -globin gene, ARMS PCR (Amplification Refractory Mutation System-Polymerase Chain
Reaction) method was used. For each sample, PCR is performed in two reactions. The first reaction amplifies gene sequence
carrying the mutation, while the other amplifies gene sequence without the mutation. Obtained PCR products were analyzed by
gel electrophoresis and it was concluded that both children carry a mutated gene, which means that they have inherited -
thalassemia from their father.

The assumption based on hematological data was confirmed. Molecular diagnostics of thalassemia syndromes is of great
importance for timely therapy that can improve clinical picture and disease prognosis.

Key Words: mutation, beta-globin gene, ARMS PCR, electrophoresis