The fragile‐X syndrome, IV. Progress towards the identification of linked restriction fragment length variants (RFLVs)

We present our strategy and progress towards the identification of rare restriction fragment length variants (RFLVs) segregating with the fragile-X syndrome. DNA from a carrier mother and two retarded sons was digested with 7 restriction endonucleases and Southern blots were probed with cloned unique X-chromosomal sequences. Two of 17 cloned segments tested revealed RFLVs between the X-chromosomes of the carrier mother. One of them detected …