TY  - JOUR
AU  - Sheth, Frenny
AU  - Liehr, Thomas
AU  - Andrieux, Joris
AU  - Tewari, Stuti
AU  - Sheth, Jayesh
AU  - Naznin, Lubna
PY  - 2018
DA  - 2018/09/07
TI  - sSMC Characterization in a Male with Turner Syndrome Stigmata
JO  - OBM Genetics
SP  - 033
VL  - 02
IS  - 03
AB  - Background: Small supernumerary marker chromosomes (sSMC) are rare cytogenetic findings in general, but especially in Turner syndrome so called sSMCT in a karyotype 46,X,mar are even more scarce. According to the literature sSMCT are derived from one of the Y-chromosome in ~70% of the cases. Thus, to identify potentially present Y-chromosomal material cases is imperative, since these cases have an increased risk of gonadoblastoma deriving from the streak gonads.
Methods: A 24-year-old short statured male presented with ambiguous genitalia, undescended testicles and elevated serum testosterone level. Karyotyping and an SRY-gene specific polymerase chain reaction (SRY-PCR) test were done. After detection of the sSMCT in metaphase directed fluorescence in situ hybridization (FISH), sex-chromosome-specific microsatellite analysis and interphase-FISH were additionally applied.
Results: In initial cytogenetic analyses the patient’s karyotype was reported as 45,X[10]; however, presence of SRY-sequences was detected by in parallel performed SRY-PCR analyses of peripheral blood. Applying FISH, a karyotype of mos 46,X,der(Y)(:p11.2->q11.1:)[7]/45,X[13] was found. However, according to microsatellite analysis using gonosome specific markers indicated for the presence of SRY in Yp11.31 and sY84 in Yq11.21, as well. Finally, interphase FISH revealed the presence of the SRY-region in ~8% of the cells. Thus, the final karyotype was defined as: mos 46,X,der(Y)(pter->p11.31::p11.2->q11.1:)[19]/46,X,der(Y)(:p11.2->q11.1:)[32]/45,X[189].
Conclusion: In the here presented sSMCT case stepwise diagnostics, using sequentially molecular cytogenetic and molecular genetic tests was necessary to finally characterize the genetic condition comprehensively. Overall, subsequent correct clinical management could now be given.
SN  - 2577-5790
UR  - https://doi.org/10.21926/obm.genet.1803033
DO  - 10.21926/obm.genet.1803033
ID  - Sheth2018
ER  -