产前诊断及分子细胞遗传学分析提示与早孕期母血清筛查中低 PAPP-A 和低 PlGF 相关的嵌合性环状 21 号染色体
Prenatal diagnosis and molecular cytogenetic characterization of mosaic ring chromosome 21 associated with low PAPP-A and low PlGF in the first-trimester maternal serum screening.
机构信息
Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan; School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan; Institute of Clinical and Community Health Nursing, National Yang Ming Chiao Tung University, Taipei, Taiwan; Department of Obstetrics and Gynecology, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan.
出版信息
Taiwan J Obstet Gynecol. 2022 Mar;61(2):359-363. doi: 10.1016/j.tjog.2022.02.029.
OBJECTIVE
We present diagnosis and molecular cytogenetic characterization of mosaic ring chromosome 21 [r(21)].
CASE REPORT
A 17-year-old, gravida 2, para 1, woman underwent amniocentesis at 17 weeks of gestation because of an abnormal result of the first-trimester maternal serum screening for Down syndrome with a free β-hCG level of 1.736 multiples of the median (MoM), a pregnancy associated plasma protein-A (PAPP-A) level of 0.275 MoM, a placental growth factor (PlGF) level of 0.281 MoM, a Down syndrome risk of 1:222 and a preeclampsia risk of 1:175. Cytogenetic analysis of cultured amniocytes revealed the result of 46,XX,r(21) (p12q22.3)[19]/45,XX,-21[13]. Array comparative genomic hybridization (aCGH) analysis of cultured amniocytes revealed the result of arr [GRCh37] 21q11.2q22.2 (15,485,008-40,625,594) × 1∼2, 21q22.2q22.3 (40,703,792-46,682,184) × 2∼3, 21q22.3 (46,761,631-48,084,156) × 1, consistent with mosaic monosomy 21 and r(21) (p12q22.3). The pregnancy was subsequently terminated, and a malformed fetus was delivered with low-set ears and hypotelorism. Postnatal cytogenetic analysis revealed a karyotype of 46,XX,r(21) (p12q22.3)[30]/45,XX,-21[8]/46,XX,idic r(21) (p12q22.3)[2] in the cord blood, 46,XX,r(21) (p12q22.3)[34]/45,XX,-21[6] in the skin, 46,XX,r(21) (p12q22.3)[37]/45,XX,-21[3] in the umbilical cord and 46,XX,dup(21) (q22.2q22.3)[32]/46,XX,r(21) (p12q22.3)[8] in the placenta. aCGH analysis of cord blood revealed the result of arr 21q11.2q22.2 (15,499,847-40,662,581) × 2.3, arr 21q22.2q22.3 (40,703,792-46,682,184) × 3.6, arr 21q22.3 (46,761,632-48,090,317) × 1, consistent with mosaic duplication of 21q11.2-q22.2 and 21q22.2-q22.3, and a 1.33-Mb 21q22.3 deletion encompassing the genes of COL18A1, SLC19A1, PCBP3, COL6A1, COL6A2, FTCD, LSS, MCM3AP, YBEY, PCNT, DIP2A, S100B and PRMT2.
CONCLUSION
Mosaic r(21) at amniocentesis may be associated with monosomy 21, idic r(21) and dup(21), and low PAPP-A and low PlGF in the first-trimester maternal serum screening.
目的
我们介绍了镶嵌环状染色体 21 [r(21)] 的诊断和分子细胞遗传学特征。
病例报告
一名 17 岁、孕 2 产 1 的女性因唐氏综合征早期母体血清筛查中游离β-hCG 水平为 1.736 中位数倍数（MoM）、妊娠相关血浆蛋白-A（PAPP-A）水平为 0.275 MoM、胎盘生长因子（PlGF）水平为 0.281 MoM、唐氏综合征风险为 1:222 和子痫前期风险为 1:175 而接受了 17 周的羊膜穿刺术。培养的羊水细胞的细胞遗传学分析显示结果为 46,XX,r(21) (p12q22.3)[19]/45,XX,-21[13]。培养羊水细胞的比较基因组杂交分析（aCGH）显示结果为 arr [GRCh37] 21q11.2q22.2 (15,485,008-40,625,594) × 1∼2, 21q22.2q22.3 (40,703,792-46,682,184) × 2∼3, 21q22.3 (46,761,631-48,084,156) × 1，符合镶嵌单体 21 和 r(21) (p12q22.3)。随后终止妊娠，并分娩出畸形胎儿，表现为低位耳和眼距过宽。产后细胞遗传学分析显示脐带血的核型为 46,XX,r(21) (p12q22.3)[30]/45,XX,-21[8]/46,XX,idic r(21) (p12q22.3)[2]，皮肤为 46,XX,r(21) (p12q22.3)[34]/45,XX,-21[6]，脐带为 46,XX,r(21) (p12q22.3)[37]/45,XX,-21[3]，胎盘为 46,XX,dup(21) (q22.2q22.3)[32]/46,XX,r(21) (p12q22.3)[8]。脐带血的 aCGH 分析显示结果为 arr 21q11.2q22.2 (15,499,847-40,662,581) × 2.3, arr 21q22.2q22.3 (40,703,792-46,682,184) × 3.6, arr 21q22.3 (46,761,632-48,090,317) × 1，符合 21q11.2-q22.2 和 21q22.2-q22.3 的镶嵌性重复，以及 21q22.3 上的 1.33-Mb 缺失，该缺失包含 COL18A1、SLC19A1、PCBP3、COL6A1、COL6A2、FTCD、LSS、MCM3AP、YBEY、PCNT、DIP2A、S100B 和 PRMT2 基因。
结论
羊膜穿刺术时的镶嵌 r(21)可能与单体 21、idic r(21)和 dup(21)以及唐氏综合征早期母体血清筛查中低 PAPP-A 和低 PlGF 相关。
Zotero 插件