Prenatal Diagnosis of Fragile X Syndrome using Amniotic Fluid DNA.

Kim, Gwang Jun; Kim, Suk Young; Hwang, Byung Cheul; Park, Chan Young; Choi, Yu Duk; Whang, Yu Jin

Original Article

Korean Journal of Obstetrics & Gynecology 2001;44(3):558-565.
Published online March 1, 2001.

Prenatal Diagnosis of Fragile X Syndrome using Amniotic Fluid DNA.

Gwang Jun Kim, Suk Young Kim, Byung Cheul Hwang, Chan Young Park, Yu Duk Choi, Yu Jin Whang

¹Department of Obstetrics and Gynecology, Gachon Medical School, Gil Medical Center, Incheon, Korea.
²Molecular genetic research center, Gachon Medical School, Gil Medical Center, Incheon, Korea.

Abstract

BACKGROUND: The fragile X syndrome is the most common cause of inherited mental retardation, is almost always caused by abnormal CGG trinucleotide amplication within the FMR1(fragile X mental retardation) gene located in Xq27.3 METHODS: DNA samples were obtained from the amniotic fluids of known carrier mother and 35 mothers without risk factors of the fragile X syndrome. Polymerase chain reaction(PCR) and Southern blot analysis were performed to evaluate the number of CGG repeats in the FMR1 gene. RESULTS: The DNA samples from the carrier mother gave a large fragment over 300 repeats by PCR. All 35 control samples showed fragments sized under 35 repeats. CONCLUSIONS: Prenatal diagnosis of the fragile X syndrome could be done with mid-trimester amniotic fluid using PCR and Southern blot method.

Key Words: Fragile X syndrome, Prenatal diagnosis