Bijlsma E K, Knegt A C, Bilardo C M, Goodman F R
Department of Clinical Genetics, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
Prenat Diagn. 2005 Jan;25(1):39-44. doi: 10.1002/pd.1080.
To describe and discuss the clinical, cytogenetic and molecular findings in a fetus with the first prenatally detected interstitial deletion of chromosome 2q.
A fetus with increased nuchal translucency on routine ultrasound examination at 13 weeks' gestation was found to have severe upper-limb abnormalities on follow-up ultrasound examination at 16 weeks. The pregnancy was terminated, and the autopsy revealed monodactyly of the right upper limb, oligodactyly of the left upper limb and bilateral split foot, as well as atrial and ventricular septal defects and mild facial dysmorphism.
Cytogenetic studies and haplotype analysis of the fetus and both parents showed that the fetus carried a de novo deletion encompassing a region of about 30 Mb on the paternal chromosome 2q (karyotype 46,XX,del(2)(q24.2-q32.2)).
This is the first instance of increased nuchal translucency associated with a chromosome 2q deletion. Moreover, the striking malformations affecting all four of the fetus' limbs support previous suggestions that a novel locus for split-hand/foot malformation (SHFM5) lies on chromosome 2q31.
描述并讨论首例产前检测到的2号染色体q臂间质性缺失胎儿的临床、细胞遗传学和分子学研究结果。
一名在孕13周常规超声检查时发现颈部半透明层增厚的胎儿,在孕16周的随访超声检查中发现有严重的上肢异常。终止妊娠后,尸检显示右上臂单指畸形、左上臂多指畸形和双侧裂足,以及房间隔和室间隔缺损和轻度面部畸形。
对胎儿及其父母双方进行的细胞遗传学研究和单倍型分析表明,胎儿携带一个源自父源2号染色体q臂约30 Mb区域的缺失(核型46,XX,del(2)(q24.2-q32.2))。
这是首例与2号染色体q臂缺失相关的颈部半透明层增厚病例。此外,影响胎儿四肢的显著畸形支持了先前的推测,即2号染色体q31上存在一个新的裂手/裂足畸形(SHFM5)基因座。