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.     

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.     

Clinical and endocrine spectrum in patients with the 45,X/46,XY karyotype

Summary Cytogenetic and endocrine studies were performed in five unrelated 45,X/46,XY individuals in an attempt to correlate them with their clinical expression and gonadal morphology. A lack of a consistent pattern between cytogenetic findings and phenotype was observed.Endocrine studies revealed a wide spectrum of hypothalamic, pituitary, and gonadal hormone production as assessed by the base line levels of LH, FSH, T, and ⁴-A and their responses to appropriate exogenous stimulation (LH-RH and HCG). An adequate correlation between endocrine findings with gonadal morphology and phenotype could be established; thus demonstrating that patients with this particular chromosome complement have a functional integrity of the gonadotropin hypothalamic pituitary activity modulated accordingly with the gonadal function of each particular case.     

Tertiary trisomy 14q-, due to paternal balanced translocation 46,XY,t(1;14)(q44;q22)

Summary Retardation of growth and mental development, craniofacial dysmorphy, limb anomalies, cryptorchidism and repeated infections are observed in a child with 47,XY,+der(14),t(1;14)(q44;q22)pat.     

Down syndrome in two siblings with 47,XY,+21 and 46,XY/46,XY,-21,+t(21q;21q)

Summary This is the first report in the literature of siblings affected with Down syndrome; one sibling had a nondisjunction of chromosome 21 and the other a (21q;21q) translocation.     

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.     

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.     

Turner syndrome mosaicism: an unusual case with a de novo large dicentric marker chromosome: mos 45,X/46,X, ter rea(X;X)(p22.3;p22.3)

X/X translocations are quite rare in humans. The effect of this anomaly on the phenotype is variable and depends on the amount of deleted material and whether the chromosomes are joined by their long or short arms. We report an unusual case of Turner syndrome mosaicism in a 16-year-old girl, who was referred to our Institute for primary amenorrhoea associated with short stature. Endocrine evaluation revealed hypergonadotropic hypogonadism, which required a study of the karyotype. Cytogenetic analysis, performed on peripheral blood leucocytes, showed a mos 45,X/46,X,ter rea (X;X)(p22.3;p22.3) de novo karyotype. The prevalent cell line was 45,X (90% cells). A second cell line (10% cells) showed a very large marker chromosome, similar to a large metacentric chromosome. FISH (fluorescent in situ hybridisation) and molecular analysis revealed that the marker chromosome was dicentric and totally derived from the paternal X chromosome.     

Translocation 46,XY,t(2;5) (q37;q14) and mental retardation. Clinical and cytogenetic study]

A boy, suffering from severe mental and motor retardation, was found to be the carrier of an apparently balanced chromosomal rearrangement studied by autoradiography and fluorescence.     

18p deletion syndrome with a 45, XY, t (14; 18) (p11;q11.2), -18, karyotype.

A dysmorphic male child of 8 months age presented with microphthalmia, micrognathia, hypertelorism, wide anterior fontanelles, large forehead, short neck, prominent ears, macrotestis and delayed developmental milestones. The patient presented with generalised seizures hydrocephalaus and Coarctation of aorta (Pre subclavian). He also had mild hypocalcaemia with normal renal function. Cytogenetic study revealed 18p(-) picture due to translocation between 14 p & 18q. Since the spectrum of clinical expression is similar to that is seen in 18p(-) syndrome it is suggested that not only whole of 18p but part of chromosome no. 18 proximal to 18 q 11.2 may also be involved in this phenotype.