Tseng Jenn-Jhy, Chou Min-Min, Lo Feng-Chu, Lai Hui-Yu, Chen Min-Hui, Ho Esther Shih-Chu
Department of Obstetrics and Gynecology, Taichung Veterans General Hospital, Department of Nursing, Hung-Kuang University, Taipei, Taiwan, R.O.C.
J Chin Med Assoc. 2009 Jan;72(1):29-33. doi: 10.1016/S1726-4901(09)70016-4.
To evaluate the clinical association of extrastructurally abnormal chromosomes (ESACs) with pregnancy outcome based on the cytogenetic characteristics of the ESACs.
We retrospectively reviewed 12 ESAC cases identified from 12,991 cases who received genetic amniocentesis between January 1983 and March 2008. Prenatal ultrasound findings, characteristics of ESACs (karyotypes, special features, origin, inheritance) and pregnancy outcomes were recorded.
The prenatal prevalence of ESACs was 0.092% (12/12,991). Of the 12 ESAC cases, all were de novo. Seven (58.3%) originated from nonacrocentric chromosomes and the other 5 (41.7%) were from acrocentric chromosomes, with 3 originating from chromosome 15. Six of the 12 cases (50%) were large ESACs; however, the other 6 (50%) were medium to small ESACs. All acrocentric ESACs contained dicentric and bisatellite characteristics. Using FISH and SKY techniques, the origins of 2 cases (patients 10 and 12) were clearly identified to be from chromosomes 15 and 10, respectively. Five of the 12 ESAC cases (41.7%) had congenital anomalies found by prenatal ultrasound. All were nonacrocentric in origin that were medium (1/5) to large (4/5) in size. After prenatal genetic counseling, 8 of the 12 (66.7%) couples opted to terminate the pregnancy. The other 4 (33.3%) continued the pregnancy and their babies were delivered at term normally and were followed-up, with normal development ranging from 2 to 17 years.
With sophisticated cytogenetic characterization and ultrasound examination, it is possible to precisely categorize most fetuses with ESACs as being either at high risk of abnormality or at a relatively low risk.
基于结构外异常染色体（ESACs）的细胞遗传学特征，评估其与妊娠结局的临床相关性。
我们回顾性分析了1983年1月至2008年3月间接受羊水穿刺的12991例患者中确诊的12例ESACs病例。记录产前超声检查结果、ESACs的特征（核型、特殊特征、起源、遗传方式）及妊娠结局。
ESACs的产前患病率为0.092%（12/12991）。12例ESACs病例均为新发。7例（58.3%）起源于非近端着丝粒染色体，另外5例（41.7%）起源于近端着丝粒染色体，其中3例起源于15号染色体。12例中有6例（50%）为大型ESACs，其余6例（50%）为中小型ESACs。所有近端着丝粒ESACs均具有双着丝粒和双随体特征。采用荧光原位杂交（FISH）和光谱核型分析（SKY）技术，明确鉴定出2例（患者10和12）分别起源于15号和10号染色体。12例ESACs病例中有5例（41.7%）经产前超声检查发现先天性异常。所有异常均起源于非近端着丝粒染色体，大小为中型（1/5）至大型（4/5）。经过产前遗传咨询后，12对夫妇中有8对（66.7%）选择终止妊娠。另外4对（33.3%）继续妊娠，其婴儿足月正常分娩并接受随访，随访2至17年发育正常。
通过精密的细胞遗传学特征分析和超声检查，有可能将大多数ESACs胎儿准确分类为高异常风险或相对低风险。
