X monosomy and balanced Robertsonian translocation in a girl with Turner Syndrome

Abstract

We describe a case of X monosomy associated with a maternally inherited t(13;14) Robertsonian translocation in a girl with Turner syndrome. The girl's X chromosome was demonstrated to be maternally inherited, ruling out the hypothesis that the translocation exerted an interchromosomal effect on the origin of the monosomy. Chromosomes 13 and 14 showed biparental inheritance. Key words: Robertsonian translocation, X monosomy, interchromosomal effect. It has been suggested that chromosomal rearrangements may disturb meiotic disjunction of chromosomes not involved in the rearrangement, resulting in an interchromosomal effect (Hamerton et al., 1968;Subri et al., 1980). We describe a case of X monosomy associated with a maternally inherited t(13;14) Robertsonian translocation in a girl with Turner syndrome. This study was approved by the ethics committee of our institution and informed consent was obtained from the parents of the girl.The five-year-old female proband was referred to our clinic because of short stature and facial dysmorphism. Clinical examination revealed short stature (< 2.5 percentile), weight between 2.5 and 10 percentile, flat frontal, large and prominent low-set ears, papebral ptosis, high nasal bridge, micrognathia, long philtrum, high palate, clinodactyly of the fifth left digit, and hypoplastic toe nails. Neuropsychological development was appropriate for the age. Chromosome analysis showed monosomy X and a Robertsonian balanced translocation -44,X,der(13;14) (q10;q10) karyotype. The girl's mother (who had a history of miscarriage) carried a balanced translocation but her father's karyotype was normal.To verify whether or not the Robertsonian translocation influenced non-disjunction of the X-chromosome, we determined the parental origin of the girl's X chromosome and normal chromosomes 13 and 14. Polymerase chain reaction was performed using DNA extracted from peripheral blood lymphocytes. We analyzed the CAG repeat on exon 1 of the X chromosome androgen receptor (AR) gene (Bharaj et al., 1999) and polymorphic markers on chromosome 13 (D13S787 and D13S895) and 14 (D14S592, D14S608 and D14S617). Our analysis showed both maternal inheritance of the X chromosome ( Figure 1) and biparental inheritance of chromosomes 13 and 14.Three previous cases of monosomy X associated with a t(13;14) translocation have been reported. Salamanca et al. (1985) reported a case of maternally inherited t(13;14) translocation but did not investigate the parental origin of the X-chromosome non-disjunction. Laszlo et al. (1984) reported the case of a patient, his mother and sister, who all had a t(13;14), but found no evidence of an interchromosomal effect. Krajinovic et al. (1994) found that both the X chromosome and the t(13;14) translocation in one of their patients were paternally inherited and thus demonstrated that the translocation had no effect on X chromosome non-disjunction. Kondo et al. (1979) compared the expected and observed frequency of the 45,X karyotype combined with unrelated balanced translocat...

Cytogenetic findings in Serbian patients with Turner’s syndrome stigmata

“…Krajinovic et al (1994) found that both X-chromosomes and the t(13;14) were paternally inherited in one of their patients. Silva et al (2006) reported a patient who had both translocation and X-chromosome that were demonstrated to be maternally inherited. All of these studies reported the association between balanced Robertsonian translocations and Turner's syndrome.…”

“…To the best of our knowledge, four cases of monosomy X associated with balanced Robertsonian translocation t(13;14) (Laszlo et al, 1984;Salamanca et al, 1985;Krajinovic et al, 1994;Silva et al, 2006) and one previous case of Turner's syndrome with familial balanced translocation t(1;2) (q32;q21)mat (Kondo et al, 1979) have been reported until now.…”

Effect of chromosome constitution variations on the expression of Turner phenotype

“…Using high resolution banding, Ozkul et al (2002) found a TS infant with the karyotype 45X,t(1;2)(q41;p16), and one case of TS with familial balanced translocation t(1;2)(q32;q21)mat was described by Kondo et al (1979). Four other studies reported an association of X-monosomy with balanced Robertsonian translocation t(13;14) (Laszlo et al, 1984;Salamanca et al, 1985;Krajinovic et al, 1994;Silva et al, 2006). Recently, Djordjević et al (2010) showed a case of 45,X,t(1;9) (cen;cen) in combination with a r(X) mosaic karyotype.…”

Turner Syndrome with Isochromosome Xq and Familial Reciprocal Translocation t(4;16)(p15.2;p13.1)

“…The coexistence of a balanced translocation and a chromosome X abnormality in Turner syndrome patients is rarely reported in the literature [4–10]. Four cases were carriers of a parentally transmitted Robertsonian translocation and had the non mosaic 44,X,t(13;14)(q10;q10) karyotype [4–7].…”

“…In addition, Xp or Xq deletions and ring (X) chromosomes may also be observed during cytogenetic analyses [3]. Coexistance of an familially transmitted autosomal translocation and Turner syndrome karyotype is a rare phenomenon and only a few cases were reported in the literature [4–10]. We here present a 16-year-old Turner syndrome patient who had an isochromosome of the long arm of chromosome X in a mosaic form and, like her mother, familial reciprocal translocation between chromosomes 4 and 16.…”