Isodicentric Y chromosome in an Ullrich-Turner patient without virilization

Abstract

We report on a 17-year-old young woman with Ullrich-Turner syndrome (UTS), who was found to have a karyotype 45,X/46,X,idic(Y)(q11). She had age-appropriate genitalia without virilization in spite of the presence of the Y-derived marker chromosome and SRY locus in 70% of her lymphocytes. Having reviewed the literature, we conclude that a possible explanation for the lack of virilization in these mosaic patients is most likely an uneven distribution of tissue mosaicism (gonadal mosaicism).

Isodicentric Y chromosomes in Egyptian patients with disorders of sex development (DSD)

“…Molecular study of patient 3 revealed a normal SRY sequence; nevertheless there was a complete failure of the SRY to induce any testicular development or virilizing signs. Many reports have failed to demonstrate any sequence changes in patients with defective testicular development and suggested that these individuals may bear mutations in other genes involved in the testis determining pathway [Fernández‐García et al, 2000; Morava et al, 2000; Alvarez‐Nava et al, 2001, 2003; Canto et al, 2004].…”

“…The proportion of the 45,X cell line in various tissues especially the gonads [Alvarez‐Nava et al, 2003; DesGroseillier et al, 2006]. Other associated factors are mutations affecting the SRY gene leading to functional loss [Canto et al, 2000; Fernandez et al, 2002] or mutations affecting other genes involved in the testis determination pathway [Morava et al, 2000; Alvarez‐Nava et al, 2001, 2003; Canto et al, 2004]. …”

Short stature as the only presenting feature in a patient with an isodicentric (Y)(q11.23) and gonadoblastoma. A clinical and molecular cytogenetic study

“…Two recent cases were described with a similar mosaicism [1,9] and one with an idic (Y) containing an even larger fragment of Yq (including DAZ) but all these patients presented with Turner stigmata, no virilisation and no evidence of a gonadoblastoma [8]. Robinson et al [13] studied 14 patients with structurally abnormal Y chromosomes and showed that in seven out of ten patients with an idic (Y) similar to the one in our patient the breakpoint was in Yq between intervals 6A±B and 7, which ®ts to the breakpoint region we de®ned (between 6A and D).…”

Chromosome Y Isodicentrics in two Cases with Ambiguous genitalia and Features of Turner Syndrome

“…The most common structural abnormalities of the human Y chromosome are dicentrics [1]. Patients with ambiguous genitalia and patients with Turner syndrome, beside a 45,X cell line, frequently have an additional one that contains structural abnormalities of the Y chromosome [2][3][4]. While the phenotypic gender can be influenced by the 45,X cell line, 4.0-6.2% of female Turner syndrome patients exhibit Y chromosome mosa icism [5][6][7][9][10][11].…”

“…While the phenotypic gender can be influenced by the 45,X cell line, 4.0-6.2% of female Turner syndrome patients exhibit Y chromosome mosa icism [5][6][7][9][10][11]. Phenotypic gender strongly depends on the percentage and distribution of the Y chromosome in the gonads, but in the other tissues mosaicism degree is variable [4,7,11]. However, studies on gonadal tis-sue are rare ly available for analysis and alternative, more easily accessible tissue is usually studied.…”