RT Journal Article SR Electronic T1 Prenatal diagnosis of myotonic dystrophy using closely linked flanking markers. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 89 OP 91 DO 10.1136/jmg.28.2.89 VO 28 IS 2 A1 Lavedan, C A1 Hofmann, H A1 Shelbourne, P A1 Duros, C A1 Savoy, D A1 Johnson, K A1 Junien, C YR 1991 UL http://jmg.bmj.com/content/28/2/89.abstract AB We report on two cases of prenatal diagnosis of myotonic dystrophy (DM), using flanking markers APOC2 or CKMM on the proximal side and D19S51 on the distal side. By double digestion (TaqI and NcoI) of PCR amplified CKMM, the informativeness was increased from a PIC value of 0.57 to 0.69. Altogether, with a PIC value of 0.64 for APOC2, 0.69 for CKMM, and 0.27 for D19S51 (BglI), presymptomatic and prenatal diagnosis can thus be offered to approximately 24% of persons with a risk between 0.0004 and 0.0008 using these flanking markers.