333ACUTE LYMPHOBLASTIC LEUKEMIA AND THE FRAGILE X PREMUTATION: CASE REPORTFragile X Syndrome is a genetic disorder showing X-linked recessive transition, seen less often relatively women and characterized by long and narrow face, forward protruding forehead and chin, large ears, large testicles. It is related various connective tissues and mental retardation (MR), ranging mostly from the mild (IQ=50-69) to severe MR (IQ=21-35). Fragile-X mental retardation 1 (FMR1) gene which is responsible for mental retardation is located in Xq27.3. This gene has been observed in the number of sick people in the CGG trinucleotide repeat sequences in the form of over 200 extends. 50- 200 of unmethylated CGG trinucleotide repeats is called the premutation carriers. In recent years increasingly emphasized that the different protein repetations produced by the genes associated with Fragile X syndrome are contribute to leukemia. The coexistence of these two disorders in a case was found remarkable in terms of the etiologic gene relation. In this case, we aimed to present a patient with acute lymphoblastic leukemia (ALL) and the fragile X premutation who has diagnosed to having "mild mental retardation" and "social anxiety disorder" (SAD)drcagatay85@gmail.comcasereport5102015 Fragile X Syndrome,Premutation,Acute Lymphoblastic Leukemia, Mental RetardationSeyhan Temtek,Cagatay Ugur,Ozden S. Uneri, H. Nese Yarali, Bahattin TuncDepartment of Child and Adolescent Psychiatry, Ankara Pediatric Hematology Oncology Training and Research Hospital, Ankara, Turkey.,Department of Child and Adolescent Psychiatry, Ankara Pediatric Hematology Oncology Training and Research Hospital, Ankara, Turkey.,Department of Child and Adolescent Psychiatry, Ankara Pediatric Hematology Oncology Training and Research Hospital, Ankara, Turkey.,Department of Pediatric Hematology, Ankara Pediatric Hematology Oncology Training and Research Hospital, Ankara, Turkey,Department of Pediatric Hematology, Ankara Pediatric Hematology Oncology Training and Research Hospital, Ankara, Turkey