Radiological signs of Leri-Weill dyschondrosteosis in Turner syndrome

BACKGROUND/AIMS: Leri-Weill dyschondrosteosis (LWD), a mesomelic short stature syndrome with Madelung deformity, was recently reported to be caused by SHOX (short stature homeobox-containing gene) haploinsufficiency. The loss of SHOX on Xp22.32, also called PHOG (pseudoautosomal homeobox-containing osteogenic gene), through structural aberrations of the X chromosome was also implicated in the short stature phenotype and some additional stigmata of Turner syndrome. The aim of this study was to systematically examine left-hand radiographs from Turner girls for the presence of signs of LWD. METHODS: We retrospectively studied 168 left-hand radiographs from 54 patients with Turner syndrome (bone age >10.5 years) who were treated with rhGH and seen during the last 10 years in our clinic. For comparison, we analyzed 7 radiographs from 5 patients with LWD and 52 radiographs from 20 patients with GH deficiency. The shape of the distal radial epiphysis (triangularisation index = TI) and the carpal angle were quantitatively measured. In addition, we screened for the presence of a premature cleft fusion or an ulnar deviation of the articular surface of the distal radial epiphysis and for fourth metacarpal shortening. One of 54 Turner girls (2%) was affected with LWD and presented with Madelung deformity. RESULTS: No milder forms of Madelung deformity were detected. However, there was a significant trend to a triangular shape of the distal radial epiphysis in Turner syndrome: the median TI was 2.7 in normal controls (range 1.8-3.7), 3.1 in Turner girls (range 2.0-6.3) (p < 0.001 against controls), and 6.0 in patients with LWD (range 3.5-11.0) (p < 0.001 against controls). CONCLUSIONS: The triangularisation index did not correlate with the carpal angle (median 122.5 Copyright 2001 S. Karger AG, Basel     

A Y/15 translocation in a 45,X male with Prader-Willi syndrome

We report a male neonate with a 45 X karyotype; the long arm of a chromosome 15 was translocated onto the proximal long arm of the Y chromosome. Breakpoints were identified by in situ fluorescence hybridization (FISH) on the proximal 15q13 and Yq11.2. The derivative chromosome has no primary centromere. Clinical features were compatible with Prader-Willi syndrome. This is the first report case ofmonosomy 15q and Yq deletion with Prader-Willi syndrome.     

Chondrodysplasia punctata with X;Y translocation

Summary We have studied a family in which the mother and her son were carriers of an X;Y translocation, der(X)t(X;Y) (p22.3;q11). The mother was of slightly short stature and had mildly short upper extremities. The son had epiphyseal punctate calcifications, mildly short extremities, a flattened nasal bridge, and mental retardation (chondrodysplasia punctata). The extra bands on the short arm of the X chromosome were identified as deriving from the long arm of the Y chromosome, using in situ hybridization with a Y-chromosome-specific DNA probe (pHY10). The chondrodysplasia punctata seen in our case may be associated with the abnormality of the distal short arm of the X chromosome caused by X;Y translocation.     

Y to X translocation in man

Summary Five new cases are added to the single published instance of Yq to Xp translocation (X_t) in man. It is shown that the anomaly can occur as a mutational event during meiosis, and can be inherited from a parent, but also that it can arise in a 47,XXY embryo. In individuals with 46,XX_t karyotype the gonadal development, sexual differentiation, gonadal function and fertility are within the range of normal females. They do not present overt or discrete sings of virilisation. However, somatic stigmata, and more specifically short stature, are present in all patients. There is no uniform pattern of X_t inactivation which varies from random to apparently preferential inactivation. This phenomenon may be important for the better understanding of X-inactivation which for the X_t the authors believe is random but followed by differential proliferation of the resulting two types of cells.Aided by grant 20 122 F.G.W.O. — Belgium.     

X/X translocation in a patient with Turner's syndrome

Summary An abnormally large X chromosome was found in a girl with Turner's syndrome, and was identified as a X/X translocation (karyotype 45,X/46,X,-X,+t(XqXp)).Aided by contract No. 20. 122 F.W.G.O., Belgium.     

Nullisomy for the distal portion of Xp in a male child with a X/Y translocation

Summary An unbalanced X/Y translocation was found in a male child with malformed external genitalia and in his mother, who are respectively nullisomic and monosomic for the distal portion of Xp and have the translocated distal segment of Yq in excess. The loss of the distal portion of Xp is supposed to be the cause of the phenotypic abnormalities present in these subjects. The phenotype of our subjects is compared with those of the other cases of X/Y translocation described in the literature.     

A Y/5 translocation in a 45,X male with cri du chat syndrome

Summary In a patient described as a 45,X male with cri du chat syndrome, combined cytogenetic and molecular methods revealed Y euchromatic material to be translocated onto the short arm of one chromosome 5, resulting in a chromosome der(5)(5qter5p14::Yp11.31Ypter). The translocated Y euchromatin comprised only the distal short arm including the pseudoautosomal region and the so-called deletion intervals 1 and 2. A review of 45,X males from the literature showed that; most of them carry a paternally transmitted Y/autosome translocations; resulting in various autosomal deletions. Depending on the segment concerned, the deletion led to congenital malformations.     

A new case of Y to X translocation in a female

Summary Cytogenetic investigation of married couples with the history of two or more recurrent abortions or unsuccessful pregnancies was carried out. The study concerns the occurrence of reciprocal translocations in regard to spontaneous miscarriages. In 115 examined couples 9 reciprocal translocations were observed, i.e., in 7.8%.     

A familial X/Y translocation: cytogenetic and molecular study

In this study we describe a 3-generation family carrying a (X;Y)(p22.3;q11.2) translocation in seven individuals of both sexes. Molecular analysis of the aberrant (X;Y)(p22.3;q11.2) chromosome was performed by FISH using X and Y-specific painting probes and also PCR amplification of the Y-specific sequences. Using these approaches it was demonstrated that the translocation resulted in a deletion of both X and Y pseudoautosomal regions. Moreover, using RBG banding it was shown that in all females the X-derivative chromosome was inactive in over 90% of mitoses. From the preliminary results obtained in this study we assumed that in this particular family the observed phenotype of the patients was caused by a deletion of the cluster of pseudoaotosomal genes responsible for the stature. More proximal loci, like STS or MRX49, were probably not deleted, since neither ichtyosis nor mental retardation was observed in this family.     

An azoospermic male with a Y/Autosome translocation

Summary This report describes an azoospermic male carrying a Y/autosome translocation. The patient had a 46,X,t(Y;10)(q12;p13) chromosome complement in a lymphocyte culture. The cytogenetic study of this patient is described, together with testicular histology, spermiogram, hormone levels, and clinical history.     

Molecular characterization of a Y;15 translocation segregating in a family

Summary We have used Y-specific and Y-derived DNA probes for in situ hybridization and Southern blotting analysis to characterize a Y;15 translocation showing normal Mendelian inheritance in a family. Cytogenetically there appeared to be an unbalanced translocation of Yqh to 15p; this translocation may be considered as a prototype of those translocations between Yq and the short arm of an acrocentric chromosome which have a population incidence of approximately 1 in 2,000. Our molecular studies showed that, in all probability, the breakpoints were near the border between Yq11.23 and Yq12, and in 15p11, respectively; the translocation is abbreviated t(Y;15)(q12;p11). Using the Y-specific probe pY431 in a quantitative Southern hybridization assay, normal females had no hybridization, female carriers and normal men had the same amount, and male carriers had twice that amount. Cytogenetic analysis and quantitative in situ hybridization using probes pY431 and pY3.4 were consistent with the hypothesis that the portion of Yq translocated to 15p comprised all of Yq12 and none of Yq11. The absence of Southern hybridization with probes specific for Yp and Yq11 confirmed this observation. Even though the family was ascertained through two brothers who both had schizophrenia and were carriers of the translocation, the clinical evaluation of a total of nine individuals with the translocation and five without it did not suggest its association with an abnormal phenotype.     

Familial Y/22 translocation in a woman

A phenotypically normal 35-year-old woman who had a malformed fetus was found to have a Y/22 translocation. One brother as well as a sister and her three children also have the Y/22 chromosome while another sister lacks it. The problem raised by the presence of this translocated chromosome for genetic counseling, especially for prenatal diagnosis, is emphasized.     

A sterile male with 45,X0 and a Y;22 translocation

Summary Cytogenetic analysis of a 20-year-old sterile male revealed a 45,X0 karyotype with no evidence for Y-chromosomal material on any of the chromosomes analysed by Q-, G- and C-banding. DNA analysis with 17 different Y chromosome-derived probes revealed the presence of Yp DNA sequences in the patient's genome. In situ hybridization with the Yp-derived probe pJA36B disclosed a translocation of Y-chromosomal material onto the short arm of a chromosome 22.     

Inactive normal X in a female leukaemic patient with an acquired X/autosome translocation

Summary An X;9;22 translocation was detected in bone marrow cells of a female patient with blastic crisis of CML. A dynamic study following 5-BrdU treatment showed that the inactive late-replicating X chromosome was the normal one. This pattern of X-chromosome replication appears to be superimposable on the most usual model found in congenital X/autosome translocations.It is suggested that preferential autosome translocation onto the active X chromosome could be the general rule in acquired X/autosome translocations associated with long survival.     

A 45,X male with translocation of euchromatic Y chromosome material

Summary A phenotypically normal 32-year-old male with azoospermia was found to have a 45,X karyotype with presence of excess euchromatic material on 14p. The parents' karyotypes are normal. This observation is interpreted as a Y/14 translocation with loss of the heterochromatic Y chromosome material.     

Familial transmission of a translocation Y/14

Summary A translocation of heterochromatic material, brightly fluorescent after actinomycin D-DAPI staining, to the short arm of chromosome 14 was prenatally detected during cytogenetic examination of cells obtained by amniocentesis on the indication of advanced maternal age. Besides this abnormal chromosome, 43 autosomes and two X chromosomes were present. Silver staining made clear that an active nucleolus-organizing region was included in the translocation product. Both the intense fluorescence and the size of the translocated extra heterochromatic block were indicative of a Yq origin. Upon cytogenetic investigation of the parents, the mother appeared to carry the same t(Y;14) chromosome. Therefore, we expected a normal girl to be born. This was confirmed after birth.     

Aspermia,associated with a presumably balanced X/autosomal translocation

Summary A new case of X/autosome translocation in a male patient is described. Azoospermia and Klinefelter like stigmata can be explained as a consequence of the balanced translocation, or by disturbed X-chromosomal inactivation during spermiogenesis.

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Zusammenfassung Es wird über einen neuen Fall einer X/Autosom-Translokation beim Mann berichtet. Azoospermie und Klinefelter-ähnliche Stigmata können unmittelbar auf die balancierte Translokation zurückgeführt werden oder Folge einer durch die Translokation gestörten X-chromosomalen Inaktivierung während der Spermiogenese sein.

     

A 45,X male with a Yp/18 translocation

Summary A patient described as a 45,X male (Forabosco et al. 1977) was examined for the presence of Y-specific DNA by using various probes detecting restriction fragments from different regions of the Y chromosome. Positive hybridization signals were obtained for Yp fragments only. In situ hybridization with two different probes, pDP31 and the pseudoautosomal probe 113F, led to a clear assignment of the Yp sequences to the short arm of one chromosome 18. Cytogenetically, the presence of all of Yp including the Y centromere on 18p could be demonstrated replacing a segment of similar size of 18p. Thus, the Y/18 translocation chromosome is dicentric structurally, but it was shown to be monocentric functionally with the no. 18 centromere active. Gene dosage studies with the probe B74 defining a sequence at 18p11.3 demonstrated a single dose of this sequence in the patient. In agreement with these observations, the patient shows clinical signs of the 18p-syndrome. It is concluded that in XO males in general, the X is of maternal origin while the maleness is due to a de novo Y/autosome translocation derived from the father. Depending on the nature of the autosomal deficiency caused by the Y/autosome translocation, the patient may have congenital malformations.