Origin and morphological features of small supernumerary marker chromosomes in Turner syndrome.

Author: Nan LIU ¹ ; Tong TONG ; Yue CHEN ; Yanling CHEN ; Chunquan CAI
Author Information

1. Tianjin Children's Hospital, Tianjin 300134, China. Email: tjln002@vip.sina.com.
Publication Type:Journal Article
From: Chinese Journal of Medical Genetics 2018;35(1):43-46
CountryChina
Language:Chinese
Abstract: OBJECTIVE To explore the origin and morphological features of small supernumerary marker chromosomes (sSMCs) in Turner syndrome. METHODS For 5 cases of Turner syndrome with a sSMC identified by conventional G-banding, dual-color fluorescence in situ hybridization (FISH) was applied to explore their origin and morphological features. RESULTS Among the 5 cases, 3 have derived from the X chromosome, which included 2 ring chromosomes and 1 centric minute. For the 2 sSMCs derived from the Y chromosome, 1 was ring or isodicentric chromosome, while the other was an isodicentric chromosome. CONCLUSION The sSMCs found in Turner syndrome have almost all derived from sex chromosomes. The majority of sSMCs derived from the X chromosome will form ring chromosomes, while a minority will form centric minute. While most sSMC derived from Y chromosome may exist as isodicentric chromosomes, and a small number may exist as rings. For Turner syndrome patients with sSMCs, dual-color FISH may be used to delineate their origins to facilitate genetic counseling and selection of clinical regime.