“…Among several PAH mutations, some seem more important, such as IV510NT546 which has been explained for PKU was identified as a G to A transition at position 546 in intron 10 of the PAH gene is representing the presence of this disease in most of the countries including Bulgaria, Italy, Turkey and especially Iran suspected that this mutation may be one of the more frequent defects in the PAH gene causing classic PKU in southern Europe [4,5,8,9]. There are several techniques used for its detection and screening, such as RT-PCR, PCR-RFLP, restriction enzymes, and sequencing [10][11][12][13].…”