Prenatal diagnosis of double autosomal mosaicism (47,XX,+8/47,XX,+14): phenotype and molecular cytogenetic analysis on different tissues

A female fetus with multiple congenital anomalies was found to have double autosomal mosaicism, 47,XX,+8/ 47,XX,+14 on chromosome analysis via amniocentesis. At delivery, the proband displayed dysmorphic features of hypertelorism, micrognathia, low set ears, cleft palate, clubfeet, omphalocele, absent gallbladder and congenital heart defects. Fluorescence in situ hybridization demonstrated a marked discrepancy in cell line populations in the tissues examined.     

Prenatal diagnosis of 45,X/46,XY mosaicism in a fetus with asymmetric gonadal dysgenesis

An 18 week abortus had been prenatally diagnosed as a 45,X/46,XY mosaic. The fetus was a phenotypic male with glandular hypospadias, a horseshoe kidney and asymmetric gonadal dysgenesis. This case represents a rare instance of prenatally diagnosed 45,X/46,XY mosaicism with an abnormal phenotype.     

Prenatal diagnosis, sonographic findings and molecular genetic analysis of a 46,XX/46,XY true hermaphrodite chimera

OBJECTIVES: To present the prenatal diagnosis, sonographic findings and, molecular genetic analysis of a 46,XX/46,XY true hermaphrodite chimera and to review the literature. CLINICAL SUBJECT AND METHODS: Amniocentesis was performed at 22 weeks' gestation because of sonographic diagnosis of ambiguous genitalia. Initial amniocentesis, repeat amniocentesis, and cordocentesis revealed a mixture of 46,XX cells and 46,XY cells. Polymorphic DNA marker analysis using the fetal and parental blood was applied to investigate the genetic origin of the chimera. A 3,625-g baby was delivered at 37 weeks' gestation with clitoromegaly, prominent labia majora, fusion of the labia, and an orifice of the urogenital sinus. A lymphangioma was noted over the right arm and was excised at age 3 days. Extraembryonic tissues and the infant's skin were cytogenetically and molecularly studied. RESULTS: Initial amniocentesis, repeat amniocentesis, and cordocentesis revealed the karyotype of 46,XX[12]/46,XY[9], 46,XX[15]/46,XY[12], and 46,XX[27]/46,XY[15], respectively. The cytogenetic results of the extraembryonic tissues and skin were consistent with prenatal diagnosis. Informative sex chromosome and pericentromeric autosome markers demonstrated double paternal and single maternal genetic contributions. CONCLUSIONS: Prenatal sonographic diagnosis of ambiguous genitalia should alert true hermaphroditism and prompt thorough genetic investigations. DNA marker analysis is helpful in delineation of true fetal chimerism as well as determination of its genetic origin in prenatally detected 46,XX/46,XY chromosome complement.     

Prenatal diagnosis of 46, XX male fetus

Prenatal diagnosis of sex differentiation disorders is extremely rare and is estimated in 1/2500 analyzed gestations. A group of this disorders are the 46, XX males and its incidence is estimated in 1/20000 male neonates. We report a male XX fetus in which the diagnosis of sex determination was requested at 20 gestation weeks to clarify the real gender of the fetus. Discrepancy between cytogenetic and ultrasonographic was detected.     

Prenatal diagnosis of a 46,XX/47,XX, + 12 mosaic

A case of true mosaicism 46,XX/47,XX,+ 12 was diagnosed prenatally. The pregnancy was terminated in the 21st week of gestation and the aberrant cell line was rediscovered in cultured fetal tissue. However, a detailed examination of the fetus did not disclose any significant physical malformation.     

Osteocraniostenosis in a fetus with a 46,XX/46,XY karyotype

Osteocraniostenosis is a disorder characterized by thin tubular bones, dymorphic facies and splenic hypoplasia/aplasia in some cases. We report a further case of this rare skeletal dysplasia in a 31 week male fetus with ambiguous external genitalia and asymmetry in whom a 46,XX/46,XY karyotype was demonstrated in both cartilage and skin.     

Prenatal diagnosis of a case of 46,XY,18p-/46,XY,18p+ mosaicism

A case of mosaicism involving structural abnormality of chromosome 18 found in cultured amniotic fluid is reported.     

Prenatal diagnosis of 45,X/46,XX mosaicism in the fetus. Should the pregnancy be terminated?

45,X/46,XX True mosaicism was found in the amniotic fluid cell culture study in our patient and was confirmed by rapid fetal blood karyotyping. Elective termination of the pregnancy revealed a morphologically normal female fetus with true mosaicism but no features of Turner's syndrome.     

Prenatal diagnosis of 45,X/46,XY mosaicism with cleft lip and epispadias

Introduction  

45,X/46,XY mosaicism is an uncommon chromosomal anomaly with a range of phenotypes from normal males to cases of multiple congenital anomalies.     

Prenatal diagnosis of trisomy 21 and X/XX sex chromosome mosaicism

Double aneuploidy involving Down syndrome and Turner syndrome is a rare chromosomal abnormality presumed to occur with a frequency of about 1 in 2 million births. Twenty-one cases of this combined anomaly have been reported and two infants were born with this anomaly after a mistake in prenatal diagnosis. We report the first prenatal diagnosis of Down syndrome combined with Turner mosaicism and suggest that this polysyndrome may be more common than previously estimated. We, therefore, wish to alert cytogenetic laboratories performing prenatal diagnoses of the potential risks of misdiagnosis of this polysyndrome if banding is not performed and if a sufficient number of mitotic cells are not analysed.     

Prenatal diagnosis of a mosaic 46,XY/47,X,i(Xq)Y

A case of mosaic 46,XY/47,X,i(Xq)Y is diagnosed at 18 gestational weeks in amniotic fluid cells and confirmed at birth in the lymphocytes of the child. The literature on Klinefelter's syndromes with structural chromosome X rearrangements is reviewed. This is the first case reported of a mosaic isochromosome Xq in a boy.     

Prenatal detection of 45,X/46,XX/47,XXX mosaicism through amniocentesis: mosaicism confirmed in cord blood, amnion, and chorion.

Sex chromosome mosaicism in amniotic fluid cells poses a serious dilemma in prenatal diagnosis. Chromosome analysis of 56 primary clones of amniocytes revealed three distinct cell lines. Nine cells (16.1 per cent) demonstrated a 45,X karyotype, 11 cells (19.6 per cent) a 47,XXX karyotype, and the remaining 36 cells (64.3 per cent) had a modal number of 46 chromosomes (46,XX). Cytogenetic evaluation of 100 cells from cord blood, amnion, and chorion following delivery confirmed this triple mosaicism. However, the distribution of the three karyotypes in the pre- and postnatal samples was not found in the same proportions. The cord blood had the most similar frequency to that of the amniotic fluid sample, while the chorion had a significantly increased frequency of 47,XXX cells (41 per cent) and a decreased frequency of 45,X cells (2 per cent). Physical examination of the infant at birth revealed no discernible phenotypic abnormalities. Parental karyotypes were normal. This case highlights the difficulty in determining whether a prenatally detected abnormality will be associated with postnatal phenotypic deviation.     

Prenatal diagnosis of 45,X/46,XX mosaicism: true mosaicism in only one of four primary cultures

45,X/46,XX mosaicism was found in only one of four primary amniotic fluid cultures. Repeat amniocentesis revealed 45,X/46,XX mosaicism in all four primary cultures. Mosaicism was confirmed in tissues from the abortus.     

Mosaicism of 46,XX/47,XX,+9/47,XX,+?mar in the same amniotic fluid with apparent loss of one cell line after delivery

A 46,XX;47,XX,+9;47,XX,+?mar karyotype was detected in an amniotic fluid cell culture and confirmed in a subsequent fetal blood sample from a 40-year-old woman. After termination of the pregnancy, none of the 186 mitoses obtained from a second blood sample was trisomic for chromosome 9 (p less than 0.001). Selection against cells containing trisomy 9 is postulated to explain the disappearance of the lymphocyte clone.     

Prenatal diagnosis of 46,XX male fetuses

Ultrasonography can accurately determine phenotypic sex differences from those of the genetic sex. Two cases were identified; they were the result of a translocation of the SRY gene from the Y chromosome to the X chromosome during meiosis. An ultrasonographic difference may represent an otherwise unsuspected genetic abnormality.     

Prenatal diagnosis of tetrasomy 47,XY,+i(12p) confirmed by in situ hybridization

A case of tetrasomy i(12p) detected prenatally is reported. The patient, a black, 32-year-old G3P2002 at 24 weeks' gestation with an unremarkable family history presented herself for prenatal care. Ultrasound examination showed a fetus with diminished femoral and humeral lengths, and hydramnios. A level II scan confirmed the presence of an omphalocele. Amniocentesis at 31 weeks showed 47,XY,+i(12p) karyotype. An infant with multiple congenital anomalies was delivered at 34 weeks. The infant died after 5 h. Genetic and ultrasonographic examinations in the third trimester were helpful in the investigation of this fetus with multiple congenital anomalies. The careful, complete team counselling afforded by this approach enabled the mother and family to be well adjusted to the strong possibility (and subsequent reality) of an abnormal infant.