Chih-Ping Chen1, Chen-Ju Lin2, Schu-Rern Chern3, Peih-Shan Wu4, Yen-Ni Chen5, Shin-Wen Chen5, Chen-Wen Pan5, Chien-Wen Yang3, Wayseen Wang6. 1. Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan; Department of Biotechnology, Asia University, Taichung, Taiwan; School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan; Institute of Clinical and Community Health Nursing, National Yang-Ming University, Taipei, Taiwan; Department of Obstetrics and Gynecology, School of Medicine, National Yang-Ming University, Taipei, Taiwan. Electronic address: cpc_mmh@yahoo.com. 2. Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medicine, MacKay Medical College, New Taipei City, Taiwan. 3. Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan. 4. Gene Biodesign Co. Ltd., Taipei, Taiwan. 5. Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan. 6. Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan; Department of Bioengineering, Tatung University, Taipei, Taiwan.
Abstract
OBJECTIVE: We present prenatal diagnosis of low-level mosaic trisomy 12. CASE REPORT: A 40-year-old woman underwent amniocentesis at 18 weeks of gestation because of advanced maternal age, which revealed a karyotype of 47,XX,+12[5]/46,XX[24] consistent with 17.2% (5/29) mosaicism for trisomy 12. Repeat amniocentesis performed at 21 weeks of gestation revealed a karyotype of 47,XX,+12[4]/46,XX[6] consistent with 40% (4/10) mosaicism for trisomy 12. Interphase fluorescence in situ hybridization (FISH) on 112 uncultured amniocytes detected 23 cells with trisomy 12 consistent with 20.5% (23/112) mosaicism for trisomy 12. Polymorphic DNA marker analysis excluded uniparental disomy 12. Array comparative genomic hybridization (aCGH) on uncultured amniocytes revealed a result of arr 12p13.33q24.33 (230,451-133,773,499) × 2.2, 17p12 (14,191,925-15,442,037) × 1.0 consistent with 10-20% mosaic trisomy 12. The father carried the 17p12 microdeletion. The fetal ultrasound findings were unremarkable. A 3958-g female fetus was delivered at 37 weeks of gestation with no phenotypic abnormality. The cord blood had a karyotype of 46,XX. Postnatal interphase FISH on urinary cells revealed 7.14% (7/98) mosaicism for trisomy 12. CONCLUSION: Low-level mosaic trisomy 12 at amniocentesis can be associated with a favorable pregnancy outcome. Interphase FISH and aCGH on uncultured amniocytes are useful for confirmation of low-level mosaic trisomy 12 at amniocentesis.
OBJECTIVE: We present prenatal diagnosis of low-level mosaic trisomy 12. CASE REPORT: A 40-year-old woman underwent amniocentesis at 18 weeks of gestation because of advanced maternal age, which revealed a karyotype of 47,XX,+12[5]/46,XX[24] consistent with 17.2% (5/29) mosaicism for trisomy 12. Repeat amniocentesis performed at 21 weeks of gestation revealed a karyotype of 47,XX,+12[4]/46,XX[6] consistent with 40% (4/10) mosaicism for trisomy 12. Interphase fluorescence in situ hybridization (FISH) on 112 uncultured amniocytes detected 23 cells with trisomy 12 consistent with 20.5% (23/112) mosaicism for trisomy 12. Polymorphic DNA marker analysis excluded uniparental disomy 12. Array comparative genomic hybridization (aCGH) on uncultured amniocytes revealed a result of arr 12p13.33q24.33 (230,451-133,773,499) × 2.2, 17p12 (14,191,925-15,442,037) × 1.0 consistent with 10-20% mosaic trisomy 12. The father carried the 17p12 microdeletion. The fetal ultrasound findings were unremarkable. A 3958-g female fetus was delivered at 37 weeks of gestation with no phenotypic abnormality. The cord blood had a karyotype of 46,XX. Postnatal interphase FISH on urinary cells revealed 7.14% (7/98) mosaicism for trisomy 12. CONCLUSION: Low-level mosaic trisomy 12 at amniocentesis can be associated with a favorable pregnancy outcome. Interphase FISH and aCGH on uncultured amniocytes are useful for confirmation of low-level mosaic trisomy 12 at amniocentesis.