Significance of assay of nucleated RBCs in umbilical cord blood in neonates with meconium-stained amniotic fluid

BACKGROUND

Approximately 8-15% of all infants are born with evidence of meconium-stained amniotic fluid (MSAF). MSAF is a potentially serious sign of fetal compromise and may indicate fetal hypoxia Objectives and aim of the work: The present study was designed to evaluate the relationship between meconium stained amniotic fluid and fetal nucleated red blood cell counts. As well, we aim to evaluate the relationship between the presence of meconium in amniotic fluid and Apgar scores in neonates.

SUBJECTS AND METHODS

A prospectively case-controlled study was performed on 40 women with clear amniotic fluid as control and 40 women with meconium-stained amniotic fluid as the study group. At delivery, 2 ml of umbilical cord blood was collected and analyzed for nucleated red blood cell (NRBC).

RESULTS

The mean NRBC counts in meconium-stained amniotic fluid was significantly higher than the control group (18.35 ± 7.7 and 9.6 ± 4.96), respectively (p < .001). There were statistically significant differences concerning 1- and 5-min Apgar scores with lower values in the MSAF group (p < .001 and .001, respectively).

CONCLUSION

Our results support previous studies which indicate the presence of meconium can be associated with chronic fetal hypoxia as demonstrated by elevated fetal NRBC levels.

Different-sized duplications of Xq28, including MECP2, in three males with mental retardation, absent or delayed speech, and recurrent infections

In XY males, duplication of any part of the X chromosome except the pseudoautosomal region leads to functional disomy of the corresponding genes. We describe three unrelated male patients with mental retardation (MR), absent or delayed speech, and recurrent infections. Using high-resolution comparative genomic hybridization (HR-CGH), whole genome array comparative genomic hybridization (array CGH), fluorescent in situ hybridization (FISH), and multiplex ligation probe amplification (MLPA), we have identified and characterized two different unbalanced Xq27.3-qter translocations on the Y chromosome (approx. 9 and 12 Mb in size) and one submicroscopic interstitial duplication (approx. 0.3-1.3 Mb) involving the MECP2 gene. Despite the differences in size of the duplicated segments, the patients share a clinical phenotype that overlaps with the features described in patients with MECP2 duplication. Our data confirm previous observations that MECP2 is the most important dosage-sensitive gene responsible for neurologic development in patients with duplications on the distal part of chromosome Xq.

Genotype-phenotype associations for ARX gene duplication in X-linked mental retardation

We screened 165 mentally retarded patients for ARX gene 428-451 base pair (bp) duplication. Eighteen individuals from five families were found to carry the duplication, and all had intellectual impairment. Twelve presented with focal hand dystonia, while six patients had EEG abnormalities including seizures. Other symptoms included speech difficulties (4/18), testis enlargement (4/18), lower limb spasticity or foot dystonia (4/18), and facial telangiectasia (3/18). These features confirm the pleiotropic effect of the duplication.