Department of Ultrasonic Medicine, Fetal Medical Centre, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
Key Laboratory for Major Obstetric Diseases of Guangdong Province, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
Prenat Diagn. 2017 Nov;37(11):1160-1168. doi: 10.1002/pd.5159. Epub 2017 Oct 23.
To explore the genetic aetiology of fetal posterior fossa abnormalities (PFAs).
This study involved cases of PFAs that were identified by prenatal ultrasonographic screening and confirmed postnatally between January 2012 and January 2016. Conventional cytogenetic analyses and chromosomal microarray analysis were performed, and chromosomal aneuploidies and copy number variations (CNVs) were identified.
Among 74 cases included in this study, 8 were of Blake's pouch cyst; 7, Dandy-Walker malformation; 11, vermian hypoplasia; 32, enlarged cisterna magna; and 16, cerebellar hypoplasia. The rates of nonbenign chromosomal aberrations (including chromosomal aneuploidies, pathogenic CNVs, and variants of unknown significance) were 2/8 (25.0%), 2/7 (28.5%), 8/11 (72.7%), 7/32 (21.9%), and 6/16 (37.5%), respectively. Cases were also classified as isolated PFAs (30/74), PFAs with other central nervous system (CNS) abnormalities (13/74), or PFAs with extra-CNS structural abnormalities (31/74). No fetuses with isolated PFAs or PFAs accompanied by other CNS abnormalities exhibited chromosomal aneuploidies or pathogenic CNVs. The rate of pathogenic chromosomal aberrations in the remaining fetuses was 17/31 (22.9%).
The combined use of chromosomal microarray analysis and karyotype analysis might assist the prenatal diagnosis and management of PFAs, with extra-CNS structural abnormalities being detected by ultrasonography.
探讨胎儿后颅窝异常（PFAs）的遗传病因。
本研究纳入了 2012 年 1 月至 2016 年 1 月期间通过产前超声筛查发现并经产后证实的 PFAs 病例。进行了常规细胞遗传学分析和染色体微阵列分析，并确定了染色体非整倍体和拷贝数变异（CNVs）。
本研究共纳入 74 例病例，其中 8 例为 Blake 氏囊囊肿；7 例为 Dandy-Walker 畸形；11 例为蚓部发育不良；32 例为扩大的第四脑室；16 例为小脑发育不良。非良性染色体异常（包括染色体非整倍体、致病性 CNVs 和意义不明的变异）的发生率分别为 2/8（25.0%）、2/7（28.5%）、8/11（72.7%）、7/32（21.9%）和 6/16（37.5%）。病例还分为孤立性 PFAs（30/74）、伴有其他中枢神经系统（CNS）异常的 PFAs（13/74）或伴有 CNS 外结构异常的 PFAs（31/74）。孤立性 PFAs 或伴有其他 CNS 异常的胎儿均未发现染色体非整倍体或致病性 CNVs。其余胎儿致病性染色体异常的发生率为 17/31（22.9%）。
联合应用染色体微阵列分析和核型分析可能有助于 PFAs 的产前诊断和管理，并通过超声检查发现 CNS 外结构异常。
