A liveborn infant with tetraploidy.

We report on an 22-month-old white girl with tetraploidy who is growing well, but who is extremely delayed in psychomotor development. When counseling parents it is important to realize that, although quite rare, tetraploid individuals can be born alive and live for at least 22 months. The implications are also relevant to prenatal diagnosis.

Long survival in trisomy-13-syndrome: 21 cases including prolonged survival in two patients 11 and 19 years old.

The mean survival in Trisomy-13-syndrome patients is reported to be 130 days. We have diagnosed 21 cases of this syndrome in this institution (11 females and 10 males); 15 patients had regular trisomy 13 and 6 had translocation-trisomy 13 karyotypes. The mean survival of the 19 patients who died was 97.05 days; translocation patients survived longer than regular trisomy patients. The oldest living patients with trisomy 13 are a girl 19 and a boy 11 years old. Both are black, have regular trisomy 13 karyotypes and have had most of the manifestations of the syndrome. No mosaicism was detected in repeated cytogenetic studies. The 19-year-old patient is the oldest known living person with regular trisomy 13.

Duplication 2q33 leads to 2q37 due to paternal ins (12;2) translocation.

An 18 month-old boy with partial duplication of the long arm of chromosome 2, based on a paternal balanced translocation, 46,XY,ins (12,2)( q23;q33q37), is described and compared with five previously reported cases. These children have in common a short nose with broad flat bridge and small anteverted nostrils, long upper lip, low-set ears, and minor digital anomalies.

Brief clinical report: an infant with duplication of 17q21 lead to 17qter.

Duplication of the distal part of 17q has been reported in 4 patients [1,2]. We are reporting clinical, autopsy, and cytogenetic data on an additional patient whose condition was due to a familial translocation in which the patient's chromosome constitution is 46,XX, der(4),t(4;17)(p16;q21) pat. The phenotype of the five known patients with this duplication is very similar, and their manifestations are distinct enough to be clinically recognizable. Abnormalities common to all five patients are severe growth impairment, craniofacial anomalies with severe hypertelorism, frontal bossing and temporal narrowness, a widow's peak, narrow palpebral fissures, a thin upper lip overlapping a thin lower lip with down-turned corners of the mouth, micrognathia, apparently low-set and deformed ears, short webbed neck, and hyperlaxity of the limbs.

Prenatal diagnosis of a familial interchromosomal insertion of Y chromosome heterochromatin.

An apparently unbalanced karyotype containing an abnormal chromosome 11 was identified in a 16-week female fetus by analysis of cultured amniocytes. Fluorescence in situ hybridization (FISH) with a chromosome 11 paint identified the presence of an insertion in band 11q24. Parental karyotyping documented an unbalanced karyotype with the same der(11) chromosome in the phenotypically normal father. CBG-banding and FISH identified the insertion to be Yq12 heterochromatin: 46,XY, der(11)ins(11;Y)(q24;q12q12).ish der(11) (wcp11+,DYZ1+). The same der(11) chromosome was also found in the phenotypically normal paternal grandmother, demonstrating this additional Y chromosomal material did not affect normal female sexual development or fertility. The parents elected to continue the pregnancy and a normal girl was born at term, further confirming that this rare familial variant has no clinical significance. This case illustrates the importance of family studies, appropriate banding, and FISH analyses to accurately characterize apparent chromosomal abnormalities.

Chromosome analysis in cases with repeated spontaneous abortions.

G-banded chromosome complements were analyzed from couples and individuals who had experienced 3 unexplained spontaneous abortions. One woman was found to be a carrier of a t(13q14q) chromosome; all other subjects had normal-appearing karyotypes. Banded chromosome studies are recommended for couples with repeated abortions in the absence of any apparent cause.

The X isochromosome-X syndrome [46,X,i(Xq)]. Report of three cases with review of the phenotype.

It is important not to confuse the 46,X,i(Xq) syndrome with the 45,X classical Turner's syndrome. There are profound cytogenetic and clinical differences between the two syndromes, which must be borne in mind in the differential diagnosis of amenorrhea and of infertility.

Cytogenetic analysis of 1375 amniotic fluid specimens from pregnancies with gestational age less than 14 weeks.

Our laboratory has received 1375 early amniotic fluid (EA) specimens during the past 5-year period for cytogenetics analysis. The gestational ages of the EA specimens were less than 14 weeks as estimated by ultrasound. The average volume of specimen received was 16 ml. Specimens were typically received in two collection tubes and cultured in Chang A and in supplemented MEM media using the in situ technique. Of the 1375 EA specimens received, 1356 were successfully cultured and yielded results. Abnormal results were found in 67 (4.9 per cent) of the cases. Nineteen specimens (1.4 per cent) failed to yield a result. The mean turn-around time (TAT) for all EA specimens was 8.28 days. In 1991, the average TAT for the EA specimens was 8.00 days compared with a TAT of 6.59 days for all specimens received over 14 weeks gestational age. The number of EA specimens received has increased from 1.5 per month in 1986 to 57 per month in 1991. In summary, our experience with EA specimens for cytogenetic analysis has demonstrated that the success rate is 98.6 per cent and that an increasing number of obstetricians are performing early amniocentesis as they seek to provide their patients with earlier results and an alternative to chorionic villus sampling.

Prenatal diagnosis of inv(X)(q12q28) in a male fetus.

Amniocentesis and prenatal chromosome analysis were performed for advanced maternal age. The fetus was male with a paracentric inversion in the long arm of the X chromosome. The mother and a brother also carried the inversion. The pregnancy continued to term and the infant is developing normally at one year of age.

4p- phenotype in an infant with t(4p-;19p or q+)mat translocation.

Four family members had an apparently balanced t(4p-;19p or q+) translocation indentified by Giemsa banding. One of these individuals, a male infant, has a 4p- phenotype with seizures, large bilateral cleft palate, abnormal anterior fontanel, abnormally shaped ears, hypertelorism, small penis with third-degree hypospadias, and bilateral simian creases. It is theorized that 4p material containing loci essential for normal development was lost in this infant by a simple deletion or "aneusomy by recombination."