Leukemoid reaction in extremely low-birth-weight infants.

The objective of this paper was to determine the incidence of leukemoid reaction and to evaluate its relationship with maternal and neonatal factors in extremely low-birth-weight (ELBW) infants. The design a case-controlled retrospective study of all live-born ELBW infants (<1000 g) over a period of 2 years, from July 1994 to June 1996. A total of 60 preterm infants were born during the study period, and are included in this report. The infants who demonstrated leukemoid reaction formed the study group, while the remainder formed the control group. Leukemoid reaction was defined as a white blood cell (WBC) count > or = 50,000/mm3. The relationship between maternal and neonatal variables and WBC counts was studied. Nine of the 60 infants studied demonstrated counts >50,000/mm3, with an incidence of 15%. There was no significant association demonstrated between maternal or neonatal variables and leukemoid reaction. Patients with leukemoid reaction had a better overall survival. Leukemoid reaction in ELBW infants is a rare and recently documented phenomenon. In our study the incidence was 15%. Although many factors have been postulated as a cause of this phenomenon, we could not demonstrate any relationship between these factors and high WBC counts, including sepsis and the use of antenatal steroids, the two most likely variables. It was interesting to note that the infants who were able to mount a leukemoid response had a better chance of survival than those who did not.

Paracentric inversion involving the long arm of chromosome 9 resulting in deletion of abl gene.

We report on a new chromosomal finding in a newborn male with hypertelorism, apparently low-set malformed ears with patent canal, micrognathia with narrow high-arched palate, bilateral webbing of neck with low posterior hairline, widely spaced nipples, and complex heart anomalies. Initially, what appeared to be a simple paracentric inversion of the long arm of chromosome 9, that is, 46,XY, inv(9)(q31q34) by routine GTG-banding technique was later determined to be a paracentric inversion with deletion of the band 9q34.1 by FISH technique using an abl unique sequence DNA probe. Thus the cytogenetic diagnosis was modified to 46,XY,der(9) inv(9)(q31q34.1)del(q34.1). Nevertheless, the presence of telomeric repeat sequences in the inverted chromosome 9 suggests that either healing has occurred by adding [TTAGGG]n sequences to the non-telomeric end (q31) by the enzyme telomerase or telomeric sequences were not affected during this inversion process. This abnormality is a rare occurrence and has never been reported before either because of a high rate of lethality or it has been undetected by routine cytogenetic techniques. The other abnormal cases with apparent paracentric inversions could also have a complex nature with congenital anomalies associated with loss of "few" DNA sequences as exemplified here.

Clinical manifestations of trisomy 4p syndrome.

UNLABELLED: Trisomy 4p syndrome is a distinct clinical entity which was noted almost a quarter century ago by Wilson et al. [71] and later was delineated by Gonzalez and colleagues [29]. The variation in the length of duplicated segment usually associated with monosomy of other genetic material which has resulted in confusion and as a result a so-called 4p syndrome could not be recognized without cytogenetic analysis. We wish to draw the attention of clinicians to this subject by presenting the description of over 75 cases including one from our clinic and stress the point that molecular approaches are imperative to characterize this anomaly. After extensive review, it appears that patients retaining at least the distal two-thirds to the entire short arm share an overlapping phenotypic expression that constitutes pure trisomy 4p syndrome which includes prominent glabella, bulbous nose with flat or depressed nasal bridge, retrognathia, pointed chin, short neck with low hairline, enlarged ears with abnormal helix and antihelix, rocker-bottom feet with prominent heel. Arachnodactyly and camptodactyly. Molecular characterization of 4p is imperative. We have also included an extensive bibliography for clinicians who may find it useful as a single reference source for evaluating their future cases. CONCLUSION: The 4p-syndrome is a distinct entity but without cytogenetic evaluation, the syndrome can not be recognized.

Postnatal decline in pyridoxal phosphate and riboflavin. Accentuation by phototherapy.

Riboflavin is a cofactor in the conversion of pyridoxine (vitamin B6) to pyridoxal phosphate (PALP), an essential coenzyme in numerous metabolic pathways, including neurotransmitter synthesis. Riboflavin and pyridoxine are light sensitive in vitro, and conflicting results have been reported on the in vivo effects of phototherapy on riboflavin. We studied 25 full-term neonates receiving phototherapy and 16 healthy controls to evaluate their riboflavin and PALP status. Both vitamin cofactors decreased in both sets of infants, but significantly more so in the irradiated group. While the biologic or clinical importance of a modest biochemical decline in the level of PALP has not been established, it is possible that transient behavioral changes in irradiated, jaundiced neonates could be mediated by decreased availability of PALP. The mechanism for the postnatal decline and the desirability of routine supplementation with pyridoxine, especially in irradiated infants, require further study.