Tulay Pinar, Ergoren Mahmut Cerkez, Alkaya Ahmet, Yayci Eyup, Sag Sebnem Ozemri, Temel Sehime Gulsum
Near East University, Faculty of Medicine, Department of Medical Genetics, Nicosia, Cyprus.
Near East University, DESAM Institute, Nicosia, Cyprus.
Glob Med Genet. 2020 Dec;7(4):128-132. doi: 10.1055/s-0041-1722974. Epub 2021 Feb 11.
Turner syndrome is a sex chromosomal aberration where majority of the patients have 45,X karyotype, while several patients are mosaic involving 45,X/46,XX; 46,X,i(Xq); and other variants. Cytogenetic analysis, karyotyping, is considered to be the "gold standard" to detect numerical and structural chromosomal abnormalities. In the recent years, alternative approaches, such as array comparative genomic hybridization (aCGH), have been widely used in genetic analysis to detect numerical abnormalities as well as unbalanced structural rearrangements. In this study, we report the use of karyotyping as well as aCGH in detecting a possible Turner syndrome variant. An apparent 16-year-old female was clinically diagnosed as Turner syndrome with premature ovarian failure and short stature. The genetic diagnosis was performed for the patient and the parents by karyotyping analysis. aCGH was also performed for the patient. Cytogenetic analysis of the patient was performed showing variant Turner syndrome (46,X,i(X)(q10)[26]/46,X,del(X)(q11.2)[11]/45,X[8]/46,XX[5]). The patient's aCGH result revealed that she has a deletion of 57,252kb of Xp22.33-p11.21 region; arr[GRCh37] Xp22.33-p11.21 (310,932-57,563-078)X1. Both aCGH and fluorescence in situ hybridization (FISH) results suggested that ( ) gene, which is located on Xp22.33, was deleted, though FISH result indicated that this was in a mosaic pattern. In the recent years, aCGH has become the preferred method in detecting numerical abnormalities and unbalanced chromosomal rearrangements. However, its use is hindered by its failure of detecting mosaicism, especially low-level partial mosaicism. Therefore, although the resolution of the aCGH is higher, the cytogenetic investigation is still the first in line to detect mosaicism.
特纳综合征是一种性染色体畸变疾病，大多数患者的核型为45,X，而少数患者为嵌合体，包括45,X/46,XX；46,X,i(Xq)；以及其他变异型。细胞遗传学分析，即核型分析，被认为是检测染色体数目和结构异常的“金标准”。近年来，诸如阵列比较基因组杂交（aCGH）等替代方法已广泛应用于基因分析，以检测数目异常以及不平衡的结构重排。在本研究中，我们报告了使用核型分析以及aCGH来检测一种可能的特纳综合征变异型。
一名明显16岁的女性临床诊断为特纳综合征，伴有卵巢早衰和身材矮小。对该患者及其父母进行了核型分析以进行基因诊断。同时也对该患者进行了aCGH检测。
对该患者进行细胞遗传学分析显示为变异型特纳综合征（46,X,i(X)(q10)[26]/46,X,del(X)(q11.2)[11]/45,X[8]/46,XX[5]）。患者的aCGH结果显示她的Xp22.33-p11.21区域缺失了57,252kb；arr[GRCh37] Xp22.33-p11.21 (310,932-57,563-078)X1。aCGH和荧光原位杂交（FISH）结果均表明位于Xp22.33的（ ）基因缺失，尽管FISH结果表明这是一种嵌合模式。
近年来，aCGH已成为检测数目异常和不平衡染色体重排的首选方法。然而，它无法检测嵌合体，尤其是低水平部分嵌合体，这限制了其应用。因此，尽管aCGH的分辨率更高，但细胞遗传学检查仍是检测嵌合体的首选方法。
