Mello Abbey L, Crotwell Patricia L, Flanagan Jason D, Woltanski Amelia R, Keppen Laura Davis, Van Eerden Peter, Boyle Jeffrey G, Stein Quinn
Sanford School of Medicine of The University of South Dakota, Sioux Falls, SD, USA.
S D Med. 2008 Sep;61(9):327-9, 331.
We report on a 20-month-old male, diagnosed prenatally with de novo mosaic ring chromosome 18 and low level monosomy 18, who also exhibited an inherited and apparently balanced translocation between chromosomes 3 and 6. We believe this to be the first reported case of prenatally diagnosed mosaic ring chromosome 18 and monosomy 18 in which the child was carried to term. Ring chromosomes are associated with an abnormal phenotype that is dependent on the amount of material that is deleted from the p and q arms. This child has a 22.5 Mb deletion of 18q and a 2.8 Mb deletion of 18p as a result of ring formation. Although the large deletion has resulted in some developmental delays and health problems, the child is making more developmental progress than was anticipated prenatally. We present his clinical course and the genetic counseling challenges associated with this case.
我们报告了一名20个月大的男性，其在产前被诊断为新发嵌合型18号环状染色体和低水平18号单体，同时还表现出3号和6号染色体之间的遗传性且明显平衡的易位。我们认为这是首例产前诊断为嵌合型18号环状染色体和18号单体且足月分娩的病例。环状染色体与异常表型相关，该表型取决于从p臂和q臂缺失的物质数量。由于环状染色体的形成，这个孩子18号染色体长臂有22.5 Mb的缺失，短臂有2.8 Mb的缺失。尽管大片段缺失导致了一些发育迟缓及健康问题，但该患儿取得的发育进展比产前预期的更多。我们介绍了他的临床病程以及与此病例相关的遗传咨询挑战。
