Fragile X Syndrome, Fetal Analysis

This test is used for prenatal diagnosis for pregnancies at risk for fragile X syndrome (FMR1).

Labcorp clients with eight-digit client account numbers should call 800-345-4363, and Labcorp Genetics & Women's Health clients with six-digit client/subclient account numbers should call 800-255-7357 to speak with a laboratory genetic coordinator before collecting specimens. In some circumstances, specimens from both parents and other family members may be required. All fetal specimens, including cord blood, must be accompanied by a maternal blood, PurFlock buccal swab kit or Oragene Dx 500 saliva kit for maternal cell contamination (MCC). A separate requisition should be submitted with the maternal specimen.

Technologies used do not detect germline mosaicism and do not rule out the presence of large chromosomal aberrations including rearrangements and gene fusions, or variants in regions or genes not included in this test, or possible inter/intragenic interactions between variants, or repeat expansions. Variant classification and/or interpretation may change with time if more information becomes available. False positive or false negative results may occur for reasons that include: rare genetic variants, sex chromosome abnormalities, pseudogene interference, blood transfusions, bone marrow transplantation, somatic or tissue-specific mosaicism, mislabeled samples or erroneous representation of family relationships. This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

Fragile X syndrome: Polymerase chain reaction (PCR) followed by capillary electrophoresis and methylation PCR analysis

Maternal cell contamination analysis (MCC): Analysis of short tandem repeat markers by multiplex fluorescent polymerase chain reaction (PCR) and capillary electrophoresis