Case of partial trisomy 2q3 with clinical manifestations of Marshall-Smith syndrome.

We describe a girl with physical anomalies, accelerated skeletal maturation, failure to thrive, and respiratory difficulties consistent with a diagnosis of Marshall-Smith syndrome (MSS). Chromosome analysis showed an inverted duplication of chromosome 2 [46,XX,inv dup(2)(q37q32) de novo] identified by G banding and confirmed by FISH. Several cases of trisomy 2q3 have been reported and established a syndrome, but the present case is the first to be associated with accelerated skeletal maturation and a clinical picture resembling MSS. This raises the possibility that the cause of MSS involves the q3 region of chromosome 2. Few reports of MSS include study of the karyotype, although the chromosomes were apparently normal in those cases where they have been examined. We suggest that karyotyping be undertaken with particular attention to the 2q3 region in patients with suspected MSS. It also would be prudent to assess bone age in all children with trisomy 2q.

Confined placental mosaicism, IUGR, and adverse pregnancy outcome: a controlled retrospective U.K. collaborative survey.

In a retrospective collaborative study involving 21 U.K. laboratories and 11,775 CVS prenatal diagnostic procedures, a total of 73 cases of confined placental mosaicism (CPM) were identified among the 8004 first-trimester referrals because of advanced maternal age, a previous child with a numerical chromosome abnormality, or a family history of the same. Data were collected on subsequent cytogenetic follow-up and pregnancy outcome for each case and a referral matched control. Comparison with the control population failed to demonstrate a marked increase in adverse pregnancy outcome in the CPM group, but a significant increase in both low and high birth weight infants was recorded. In a parallel study, 7 out of 108 cases, referred for prenatal diagnosis because of ultrasound detection of isolated intrauterine growth retardation (IUGR) in the second or third trimester, were shown to have a chromosome abnormality restricted to the extraembryonic tissues. These included cases of CPM involving trisomy 9 and del(13)(q13), neither of which has previously been reported in association with IUGR.

Early amniocentesis at 11-14 weeks' gestation for the diagnosis of fetal chromosomal abnormality--a clinical evaluation.

Early amniocentesis between 11 and 14 weeks' gestation was offered to 110 women at risk of a chromosomally abnormal fetus due to maternal age. Four were found to be unsuitable for the procedure, and 106 early amniocenteses were performed. In 102 cases, clear amniotic fluid was obtained with a single tap. There were two dry taps and two bloodstained taps; sampling was repeated in three of these cases before 15 weeks. In the fourth case, placental biopsy was performed at 16 weeks. Thus, we were able to obtain a satisfactory sample in all but three cases (2.8 per cent). Karyotyping of cells harvested from the early amniotic fluid samples was successful in all the 105 cases. Cell culture from the initial samples revealed a normal karyotype in 99 cases, two balanced translocations, two tetraploid karyotypes, and two cases of pseudomosaicism. Of the 105 pregnancies successfully sampled, there have been two losses to date (1.8 per cent). Two further patients presented with premature rupture of membranes, both pregnancies having successful outcomes. Sixty-two babies have delivered to date, with four congenital anomalies. There were no respiratory problems. Twenty-nine pregnancies are continuing without known complications, and details are not yet available on the remaining 12. The results indicate that early amniocentesis may replace the traditional test at 15-17 weeks.

Cytogenetic studies of amniotic fluid taken before the 15th week of pregnancy for earlier prenatal diagnosis: a report of 114 consecutive cases.

One hundred and fourteen samples of amniotic fluid taken before 15 weeks of gestation were cultured for cytogenetic studies. The results of culturing these early amniotic fluid (EAF) samples were compared with the results of culturing 114 standard amniotic fluid (SAF) samples taken after 15 weeks of gestation matched for maternal age and received in the laboratory within the same week. Cell culture was successful in all 114 of the EAF samples and in 111 SAF samples. There was no significant difference in the days to harvesting and days to reporting in the two groups. Three samples of SAF failed to grow and two EAF samples produced tetraploid karyotypes, so that in these five cases amniocentesis had to be repeated. These problems were attributed to toxicity of a fungicide used in the culture medium. Pseudo-mosaicism was noted in two EAF samples and one SAF sample; and maternal cell contamination was noted in one EAF and one SAF sample. Thus, culturing and karyotyping cells harvested from EAF and SAF are similar, indicating that EAF samples from 12-14-week pregnancies could be used for prenatal diagnosis.

A case of interstitial deletion of 10q25.2----q26.1.

A de novo interstitial deletion of chromosome 10, del(10)(pter----q25.2::q26.1----qter), was detected in a newborn female with facial anomalies, failure to thrive, and subsequent developmental delay. This case is compared with 10 previous reports of monosomy 10q within the q25----qter region.