Cytogenetic analysis of spermatozoa in a patient with chromosome constitution 45,X/46,X,r(Y) by intracytoplasmic injection into mouse oocytes

The chromosome set of human spermatozoa was studied by intracytoplasmic injection into mouse oocytes. A total of 85 metaphase plates of male pronuclei of a patient with chromosome constitution 46,X,r(Y)/45,X and 108 metaphase plates of patients with normal sperm parameters (control group) were examined. The ratio between X- and Y-bearing chromosomes in the 46,X,r(Y)/45,X patient and in the control group did not differ from 1:1. A significant increase in the rates of diploidy, hypoploidy, hyperploidy of sex chromosomes, and chromosome structure rearrangements in spermatozoa of the patient in comparison with spermatozoa in the control group was recorded.     

Ring Y chromosome: 45,X/46,X,r(Y) chromosome mosaicism in a phenotypically normal male with azoospermia

Summary Chromosome analysis of lymphocytes in a phenotypically normal male with azoospermia showed a mosaicism 45,X/46,X,r(Y). Seven other cases from the literature are discussed.     

Monozygotic twins with Turner's syndrome and mos 45,X/46,X,r,(Y)

A pair of monozygotic twins with Turner's syndrome was studied using combined cytogenetic techniques and a mos 45,X/46,X,r(Y) was demonstrated in both. One of the twins presented clitoral hypertrophy. Surgery was performed and uterus, bilateral Fallopian tubes, bilateral epididymis and bilateral streak gonads with a small nodule of testicular tissue containing numerous seminiferous tubules were found in both.     

Nonmosaic 46,X,r(Y) karyotype with female phenotype

Summary A nonmosaic case of ring Y chromosome is described. The patient is phenotypically female and has streak gonads. The histologic examination revealed dysgenetic seminiferous tubules in the streaks and epididymislike tubules besides them. The possibilities of the development of the phenotype and the streaks are discussed.Supported by the Scientific Research Council, Ministry of Health, Hungary, 5-12-1101-02-1/L.     

Ambiguous Genitalia in a Newborn with 45,X/46,X,Idic(Y) Ovotesticular Disorder of Sex Development

ObjectiveTo discuss a case of ovotesticular disorder of sex development (DSD) with ambiguous genitalia, isodicentric Y sex chromosome mosaicism, and unique histopathologic findings.MethodsWe report the clinical, laboratory, imaging, and operative findings, and we highlight the pertinent features of this case. Results of hormonal and genetic testing are reviewed, and histopathologic findings are illustrated.ResultsA term newborn had ambiguous genitalia and was found to have an uncommon 45,X/46,X,idic(Y) karyotype. This infant had a 2-cm phallic structure, a penoscrotal hypospadias, a gonad easily palpable in the right scrotum, and a second gonad palpable high in the left inguinal canal. On ultrasonography, both gonads appeared as normal testicles, and no müllerian structures were identified. Testosterone and dihydrotestosterone levels were normal for a male neonate. After assessment of the patient at 2 months of age because of an incarcerated left inguinal hernia, both gonads were removed and were found to have both testicular and ovarian tissues spread throughout, with a fallopian tube on the left and an incipient juvenile granulosa cell tumor on the right. He was then diagnosed with ovotesticular DSD and continued to be raised as a boy.ConclusionThis male infant had undervirilization and an ovotesticular DSD. He had evidence of both ovarian and testicular tissues, in conjunction with apparent alterations in local müllerian inhibiting substance levels that allowed one fallopian tube to be preserved. The proportion of actively transcribed Y material in the chromosomes of patients with this karyotype may partially explain the variable phenotypes that can occur. (Endocr Pract. 2009;15:732-736)     

Dicentric Y chromosome in a male pseudohermaphrodite 45,X/46,X, dic (Y)/47, XYY]

The mosaicism 45,X/46,XY,terrea(Y,Y)(pterpter)/47,XYY was observed in an 8-month-old child with male pseudohermaphroditism. The presence of a 47,XYY population points to a post-zygotic origin of the rearrangement. The loss of Yp material is in favor of localization of masculinization factor(s) to the proximal segment of Yq. Twenty-two relevant observations reported in the literature previously are discussed.     

Distamycin A-DAPI banding of nonfluorescent Y (Ynf) chromosomes in 45,X/46,XYnf mosaicism

Summary The distamycin A-DAPI banding patterns of nonfluorescent, nonheterochromatic Y chromosomes (Y^nf) in two patients with 45,X/46,XY^nf mosaicism were investigated. In both cases moderately fluorescent bands were observed near the centromere and on the distal long arm of the Y^nf. These bands were similar to the centrometric band on normal Y chromosomes and support the hypothesis that the Y^nf is an isodicentric chromosome derived from the proximal portion of the Y chromosome.     

A complex mosaicism 45,X/46,X,del(Xq)/46,X,idic(Xq) in a patient with secondary amenorrhea

A complex mosaicism involving the X chromosome was found in a 35-year-old female affected by secondary amenorrhea and short stature. Her karyotype was: 45,X[20]/46,X,del(X)(pter-->q26::qter)[15]/46,X,idic(X)(pter-->q26::q26-->pter)[9]. No cell contained both abnormal X chromosomes. This observation would suggest a possible mechanism underlying the formation of isodicentric chromosomes.     

FISH and PCR analyses in three patients with 45,X/46,X,idic(Y) karyotype: clinical and pathologic spectrum

OBJECTIVE: To delineate the phenotypic spectrum (clinical and gonadal features) from patients with a 45,X/46,X,mar(Y) karyotype based upon of their clinical, histological, cytogenetic and molecular evaluation. SUBJECTS: Three patients with a 45,X/46,X,mar(Y) karyotype. METHODS: Clinical assessment, karyotyping, endocrine evaluation, FISH and PCR analyses of several Y-chromosome loci and direct sequencing of the SRY gene. RESULTS: The patients, two males and one female had varying degrees of impairment of sexual differentiation, with or without testis formation. One patient (reared as female and aged 17 years) had Turner syndrome with bilateral streak gonads. The second patient (2.4 years old) had ambiguous genitalia and presented a dysgenetic testis with a contralateral streak gonad. A third patient (26 years old) had bilateral dysgenetic testes (dysgenetic male pseudohermaphroditism). The ratio of 45,X vs. 46,X,+mar(Y) cells differed between patients and between different tissues. In each case the marker sexual chromosome was identified as a rearranged Y-chromosome (idic(Y)) using FISH and PCR analyses. In all cases the SRY gene was present in all tissues studied. No mutations were identified in this gene in any of the patients. CONCLUSIONS: The extent of male or female differentiation in these patients depends in part on the prevalence, time occurrence, and distribution of the 45,X cell line.     

Mosaicism 45,X/46,X, t dic(Xp:Xp) in a girl with short stature

An eight-year-old girl with marked short stature and no apparent stigmata of Turner syndrome was investigated. Clinical features include bilateral epicanthic folds, frontal bossing, prominent ears and normal intelligence. Ultrasound scanning revealed an apparently normal vagina, streak ovaries and no uterus. Bone age was normal. Karyotype analysis of peripheral blood lymphocytes showed mos 45,X/46,X tdic(Xp:Xp) in the ratio 66:34, respectively. In addition, three cells with different abnormal X chromosomes were present which possibly originated from a 46,XX clone. Replication of the duplicated X chromosome was consistently late and symmetrical. Buccal smear confirmation of the karyotype showed Barr body negative in 90% and large or bipartite in 10% of the cells. Karyotypes of the parents were normal. The clinical manifestations in cases of Xp deletion due to terminal rearrangement associated with or without a 45,X cell line are discussed.     

Chromosome 22 mosaic monosomy (46,XY/45,XY,-22)

A slightly dysmorphic and mentally defective child with mosaic monosomy 22 is reported. Chromosome 22 is absent in 10.5% of lymphocytes and 8.3% of fibroblasts. This is the second case report of that kind.     

A case of ambiguous genitalia presenting with a 45,X/46,Xr(Y)(p11.2;q11.23)/47,X,idic(Y)(p11.2),idic(Y)(p11.2) karyotype

An infant with ambiguous genitalia was found to have a karyotype 45,X/46,X,r(Y)(p11.2;q11.23)/47,X,idic(Y)(p11.2),idic(Y)(p11.2) using G-banding, C-banding and FISH. Examination of the genitalia revealed a phallus measuring 1.5 cm in length and 0.5 cm wide with perineal orifice. Subtle phenotypic features consistent with Turner syndrome were not present. Genital ultrasonography revealed the presence of an infantile uterus. Endoscopy of the vagina, uterus and cervix appeared normal.     

Cell division and sister chromatid exchanges in 45,X/46,X,i(Xq) mosaicism

Summary The kinetics of cell division and sister chromatid exchanges were studied in PHA-stimulated short-term cultivations of peripheral blood by means of the BUDR/FPG technique in controls and in five patients with 45,X/46,X,i(Xq) mosaicism. No significant differences in the length of the cell cycle were observed between 45,X/46,X,i(Xq) and control 46,XX cells. The number of SCE on late i(Xq) was only nonsignificantly elevated (0.6 per i(Xq)) against the value expected on the basis of its relative length.