Mosaic Turner Syndrome With 45,X/46,XY Mosaicism and Apparent Absent Uterus

Abstract

Turner syndrome (TS) is a relatively common chromosomal abnormality in females. Short stature, gonadal dysgenesis, and somatic dysmorphic features are the characteristic features of the syndrome. The chromosomal abnormalities of TS are highly variable; 45,X/46,XY mosaicism accounts for 10-12% of cases of Turner syndrome. Despite the presence of hypogonadism, affected females typically have a uterus. Here, we report the case of a 22-year-old female who presented at 15 years of age with primary amenorrhea. She was diagnosed with Turner syndrome mosaicism with a karyotype of 45,X/46,XY. Her pelvic imaging showed an absent uterus and ovaries. Due to the presence of a Y chromosome, she underwent prophylactic gonadectomy. Histopathology of her removed gonads confirmed the diagnosis of mixed gonadal disorder. She was started on estrogen replacement. Four years after treatment, she developed her menses. Her repeated pelvic magnetic resonance imaging showed the presence of a small uterus.

Clinical and molecular cytogenetic findings and pregnancy outcomes of fetuses with isochromosome Y

“…Jie Xu et al found that > 20% of G-banded amniocytes with idic Yp seemed to correlate with phenotypically healthy males in most cases in the absence of other indicators of fetal structural anomalies [ 44 ]. High levels of the mosaicism of 45,X and low levels of idic(Y)/i(Y) cell lines in gonads may lead to mosaic loss, the haploinsufficiency of SRY , and an inability to maintain normal testosterone differentiation, thus manifesting in ambiguous genitalia or a female phenotype [ 45 – 48 ]. However, a lack of correlation between the level of mosaicism in AF cells and the phenotypic sex has been reported [ 49 – 51 ].…”

Early Bilateral Gonadoblastoma in a Patient with Mixed Gonadal Dysgenesis (Karyotype 45,X/46,XY): Case Report and Review of Literature

“…As in the presented case, gonads are frequently a unilateral dysgenetic testis and a contralateral streak-like gonad with persistent asymmetrical Mullerian structures: underdeveloped uterus, fallopian tube ipsilateral to the streak-like gonad [ 6 , 13 ]. The broad range of phenotypical variations in MGD may be explained by the proportion of mosaic karyotype that is expressed in gonadal and other tissue cells [ 14 , 15 ]. Frequently Turner syndrome characteristics are found in individuals with 45,X/46,XY, the presence of 45,X cell line is associated with Turner syndrome fenotype [ 5 , 7 , 15 , 16 ].…”

“…The broad range of phenotypical variations in MGD may be explained by the proportion of mosaic karyotype that is expressed in gonadal and other tissue cells [ 14 , 15 ]. Frequently Turner syndrome characteristics are found in individuals with 45,X/46,XY, the presence of 45,X cell line is associated with Turner syndrome fenotype [ 5 , 7 , 15 , 16 ]. Gonadal development and differentiation is determined by the predominant karyotype in gonadal tissue cells.…”

Prenatal diagnosis of sex chromosome aneuploidy—What do we tell the prospective parents?

“…The presence of Y chromosome material with a dysgenic gonad increases the risk of gonadoblastoma, which is further increased if the gonad is undescended. 38,39 The percentage of Y chromosome-containing cells on the peripheral blood karyotype may correlate with degree of virilization of the external genital structures, but this association is imperfect. Some features of TS are common in those with Y chromosome mosaicism, such as reduced growth, and gonadal dysfunction.…”

“…External genitalia may develop into typically female, typically male, or neither typically male nor female (intersex). The presence of Y chromosome material with a dysgenic gonad increases the risk of gonadoblastoma, which is further increased if the gonad is undescended 38,39 . The percentage of Y chromosome‐containing cells on the peripheral blood karyotype may correlate with degree of virilization of the external genital structures, but this association is imperfect.…”