Prenatal diagnosis of a rare case report of 45,X/46,X,dic(X) and literature review

Objective: We present a prenatal case of 45,X/46,dic(X) with two asymmetric chromosome arms. Methods Single nucleotide polymorphism array(SNP-array),fluorescence in situ hybridization(FISH) and conventional cytogenetic analysis were performed for verification. Results The conventional G-banding analysis revealed a mosaic karyotype of mos 45,X/46,X,dic (X;X) (p11.2;q10) and the C-banding analysis showed that the derivative X chromosome had two darkly stained bands near the centromere.Two green signals and single green signal (X chromosome cetromere) were observed simultaneously in the metaphases and interphases FISH confirmation test,which indicated a mosaicism for X chromosome in the uncultured amniocytes.The SNP-array results revealed two copy-number-loss on the X chromosome.One was a 54.3Mb deletion in Xp22.33-p11.22 including 414 genes.Another was a mosaic deletion in Xp11.22-q28. Conclusion A combination of molecular and cytogenetic techniques should be employed to provide adequate genetic counseling to mosaic Turner sydrome patients for avoiding misdiagnosis.