45,X/46,X, + r(X) can have a distinct phenotype different from Ullrich-Turner syndrome

We present a patient with 45,X/46,X, + r(X) mosaicism and lack of inactivation of either the normal or the ring X in the 46,X, + r(X) cells. The patient has mental retardation, syndactyly, minor facial anomalies, and a congenital heart defect. Although most patients with 45,X/46,X, + r(X) have the Ullrich-Turner syndrome, 2 previously described patients with this karyotype also had a distinct phenotype consisting of severe mental retardation, syndactyly, and abnormal face. The unusually severe phenotype in these patients was thought to be due to lack of X-inactivation of the ring X chromosome. The findings in our patient support this hypothesis.     

Ullrich-Turner phenotype with unusual manifestation in a patient with mosaicism 45,X/47,XX,+18

We report on a girl with Ullrich-Turner phenotype and 45,X/47,XX,+18 chromosomal mosaicism. Only two other patients with similar mosaicism have been reported, both girls with XY sex chromosome constitution. The face of the patient was highly asymmetric, the right side being almost normal, the left showing a typical Ullrich-Turner syndrome appearance. This clinical impression was strengthened by photographic doubling of both hemifaces. The patient had normal intelligence and did not show any stigmata of trisomy 18. © 1996 Wiley-Liss, Inc.     

Turner phenotype in a girl with a 45,X/46,XX/47,XX,+18 mosaicism

We report a girl with Turner syndrome phenotype, whose karyotype on amniocyte culture was 45,X, while cytogenetic analysis on peripheral blood lymphocytes showed the presence of a mosaic chromosome constitution with three different cell lines: 45,X[5]/46,XX[3]/47,XX,+18 [35]. No signs of trisomy 18 were observed and a follow up during childhood revealed normal psychomotor development. Parental origin and mechanism of formation were studied using high polymorphic microsatellites and Quantitative Fluorescent PCR. The 18-trisomic cells showed one paternal allele and two maternal homozygous alleles at different loci of chromosome 18, suggesting a maternal M-II meiotic or a postzygotic error. A biparental origin of the X-alleles in the trisomic cells were determined, being the paternal allele retained in the 45,X cells. The possible mechanism of formation implying meiotic and/or mitotic errors is discussed.     

Novel karyotype in the Ullrich-Turner syndrome—45,X/46,X,r(X)/46,X,dic(X)—investigated with fluorescence in situ hybridization

A 10-year-old girl with Ullrich-Turner syndrome was found to have the novel karyotype 45,X/46,X,r(X)(p11q11)/46,X,dic(X)(p11). Fluorescence in situ hybridization (FISH) with the α satellite X centromere probe established the origin of the small ring chromosome. Scanning a large number of cells by interphase FISH showed that the dicentric (X) was the least prevalent cell line. The common breakpoint of Xp11 suggests a sequence of errors as the mechanism whereby these 3 distinct cell lines have arisen. © 1994 Wiley-Liss, Inc.     

Mental retardation and Ullrich-Turner syndrome in cases with 45,X/46,X,+ mar: Additional support for the loss of the X-inactivation center hypothesis

Four cases having mosaicism for a small marker or ring [45,X/46,X,+mar or 45,X/46,X,+r] chromosome were ascertained following cytogenetic studies requested because of minor anomalies (cases 1, 3, and 4 ) and/or short stature (cases 2 and 4). While all 4 cases had traits typical of Ullrich-Turner syndrome (UTS), cases 1, 3, and 4 had manifestations not usually present in UTS, including unusual facial appearance, mental retardation/developmental delay (MR/DD) (cases 3 and 4), and syndactylies (case 1). The facial appearances of cases 1 and 3 were similar yet distinct from that of case 4. Using fluorescence in situ hybridization (FISH), each of the markers in these 4 cases was identified as having been derived from an X chromosome. The level of mosaicism for the mar/r(X) cell line in these cases varied from 70% (case 1) to 16% (case 4) but was not apparently correlated with the presence of MR/DD. Replication studies demonstrated a probable early replication pattern for the mar/r(X) in cases 1,3, and 4, while the marker in case 2 was apparently late replicating. To date, 41 individuals having mosaicism for a small mar/r(X) chromosome have been described. Interestingly, most of the 14 individuals having a presumedly active mar/r(X) demonstrated clinical findings atypical of UTS, including abnormal facial changes (11) and MR/DD (13). MR was noted most frequently in those cases having at least 50% mosaicism for the marker or ring. In contrast, atypical UTS facial appearance or MR/DD was not noted in 14 of the 16 cases with UTS who carried a probable late replicating marker or ring. In conclusion, although the phenotype of 45,X/46,X,mar/r(X) individuals appears to be influenced by the genetic content and degree of mosaicism for the mar/r(X), the most significant factor associated with MR/DD appears to be the activity status of the mar/r(X) chromosome. Thus, our 4 cases provide further support for the hypothesis that a lack of inactivation of a small mar/r(X) chromosome may be a factor leading to the MR and other phenotypic abnormalities seen in this subset of individuals having atypical UTS. © 1994 Wiley-Liss, Inc.     

45X/46X,r(X) with syndactyly and severe mental retardation

Two white females, age 2 1/2 and 33 years, respectively, were investigated because of severe mental retardation associated with neurologic abnormalities, coarse face, and soft tissue syndactyly involving upper and lower limbs. Each had cytogenetic findings of a mosaic variant of Ullrich-Turner syndrome with X ring chromosome in peripheral lymphocyte and skin fibroblasts. Early X replication occurred in one-third of the X ring chromosomes; there was no evidence for X-autosome translocation involving either X and an autosomal duplication; results of studies for fragility of the X chromosomes were unremarkable. In situ hybridization with an X centromere probe was positive for the ring. To our knowledge, the unusual constellation of cytogenetic, physical, and mental findings seen in these 2 individuals has not been reported previously.     

45，X／46，Xr（X）（p22．2∷q13）一例

患儿女，10岁。第1胎，足月顺产。因生长发育迟缓，来我室就诊。患儿出生时一般情况良好，生后身高增长缓慢，就诊时身高110cm，肘外翻，外眼角上斜，有条索状性腺，表现为Turner综合征体征，但无蹼颈。双亲表型正常，非近亲婚配，患儿出生时父龄27岁，母龄25岁，其母孕期无感冒、发热、也无化学药物及放射线物质接触史，家族中无类似病史。     

45,X/46,X,+mar核型Turner综合征患儿额外小标记染色体来源和形态研究

遗传学特征,以指导遗传咨询、产前诊断和确定临床治疗方案.     

45,X/46,X,idic(X)两例

例1 女,16岁,无月经来潮,身材矮小,身高138cm,表情呆滞,反应迟钝.查体:头发浓密,发际低,轻度蹼颈,肘外翻明显,女性第二性征无发育.外生殖器呈女性特征,阴毛稀疏,大小阴唇幼稚型.激素水平测定:促卵泡激素和黄体激素水平高于正常,与绝经期女性值相近,雌二醇(E2)测定值很低.B超提示:始基子宫.细胞遗传学检查:常规外周血淋巴细胞染色体培养、核型分析.     

Three patients with a 45,X/46,X,psu dic(Xp) karyotype.

Few cases of isochromosomes for the short arm of the X have been reported and all are dicentric with variable portions of the long arms interposed between the two centromeres. This paper reports three cases of complete short arm duplication of one X chromosome in unrelated female patients. All patients also have a 45,X cell line and present with some characteristic features of Turner syndrome. We used conventional cytogenetics, in situ hybridisation, and molecular genetics to describe all three structurally abnormal chromosomes and the parental origin of two of them. We briefly discuss the "inactivation enhancement" theory; however, any genotype-phenotype correlation is complicated by the presence of the 45,X cell line.     

45，X／46，X，ter rea（X；X）一例

患者 社会性别女，24岁，未婚。因原发性闭经就诊。智力无异常。父母非近亲婚配。家族中否认遗传病和其他特殊病史。查体：身高173cm，体重62kg。无特殊面容，发际不低，无颈蹼，指间距174cm，无肘外翻。双侧乳房发育欠佳，乳间距宽。外阴呈幼稚型、阴毛稀少。B超示：始基子宫，双侧卵巢未探及，有阴道。     

A non-sex chromosome marker in a patient with an atypical Ullrich-Turner phenotype and mosaicism of 46,X,mar/46,XX

The absence of a sex chromosome in conjunction with the presence of a marker chromosome generally implicates a sex chromosome origin for such marker chromosomes. These types of findings are frequently associated with Ullrich-Turner syndrome. We report a patient that presented with an atypical Ullrich-Turner phenotype and a cytogenetic mosaicism of 46,X,mar/46,XX. The marker chromosome was derived from chromosome 20, not from the X or Y chromosome. The patient's clinical features are described and discussed relative to the cytogenetic findings. This case further demonstrates the necessity of marker chromosome identification for accurate phenotype-karyotype correlation.     

Ullrich-Turner syndrome in mother and daughter: Prenatal diagnosis of a 46, X,del(X)(p21) offspring from a 45, X mother with low-level mosaicism for the del(X)(p21) in one ovary

A woman with Ullrich-Turner syndrome but with normal secondary sex characteristics became pregnant on two occasions (ages 23 and 24). She had a 45, X karyotype in 100/100 lymphocytes and 50/50 skin fibroblasts. The first pregnancy ended in a miscarriage at 2 months of gestation. In the second pregnancy cultured amniocytes showed a 46, X, del(X)(p21) karyotype. This pregnancy resulted in an apparently normal girl. Biopsies of the mother's ovaries were obtained at the time of cesarean section. Grossly the ovaries appeared normal, and histologically the number of primordial follicles appeared normal. In the right ovary, 5/100 cells were 46, X, del(X)(p21), while all 100 cells in the left ovary were 45, X.     

Ullrich-Turner syndrome in mother and daughter: prenatal diagnosis of a 46,X,del(X)(p21) offspring from a 45,X mother with low-level mosaicism for the del(X)(p21) in one ovary

A woman with Ullrich-Turner syndrome but with normal secondary sex characteristics became pregnant on two occasions (ages 23 and 24). She had a 45,X karyotype in 100/100 lymphocytes and 50/50 skin fibroblasts. The first pregnancy ended in a miscarriage at 2 months of gestation. In the second pregnancy cultured amniocytes showed a 46,X,del(X)(p21) karyotype. This pregnancy resulted in an apparently normal girl. Biopsies of the mother's ovaries were obtained at the time of cesarean section. Grossly the ovaries appeared normal, and histologically the number of primordial follicles appeared normal. In the right ovary, 5/100 cells were 46,X,del(X)(p21), while all 100 cells in the left ovary were 45,X.     

Ullrich-Turner syndrome: Seven pregnancies in an apparent 45,X woman

A 37-year-old woman was referred for genetic counseling after termination of her probable seventh pregnancy. Ultrasound examination at 13 weeks of gestation had shown a fetus with bilateral cystic hygromas. A transabdominal amniocentesis confirmed 45,X karyotype in the fetus. The patient had marked short stature and a 45,X chromosome constitution in blood lymphocytes. Subsequently she had a hysterectomy and oophorectomy. Tissue of representative sites of the pathological specimen showed a 45,X chromosome constitution. However, molecular analysis of 8 sites from the uterus and ovaries, and of skin fibroblasts with X-chromosome microsatellites showed the presence of only one allele, except for the microsatellite DXS996 which demonstrated 2 alleles (155 bp and 161 bp) in ovarian tissue. The lymphocytes from the mother and her only son demonstrated the same single allele (161 bp). We conclude that molecular analysis of lymphocytes and of tissue is necessary for detecting low-level mosaicism in apparently homogeneous 45,X women. Am. J. Med. Genet. 75:1–3, 1998. © 1998 Wiley-Liss, Inc.     

Turner's syndrome and 45, XO/46, X, del(X)(p11p22) karyotype

This paper presents a female patient with a clinical picture of Turner's syndrome and the chromosomal constitution: 45, XO/46, X, del(X)(p11 p22).     

Gonadal dysgenesis with 45,X/46,X,dic(Yp) mosaicism

A female patient with a gonodal mucinous cystadenoma on the right side and a gonado-blastoma on the left was found to be a 45,X/46,X,dic (Yp) mosaic, This brings the total number of cases with dicentric Y chromosome reported to date to 23.
Together with the available evidence, the information derived from this case supports the hypothesis that the gene on the long arm of the Y chromosome is responsible for the initiation of testicular differentiation, whereas that on the short arm is responsible for the maturation of the testes.