Prenatal differentiation of ventral abdominal wall defects. Are amniotic fluid markers useful adjuncts?

We retrospectively reviewed 29 cases of ventral abdominal wall defects to evaluate the usefulness of amniotic fluid markers in the prenatal assessment of those disorders. Amniotic fluid alpha-fetoprotein (AF-AFP) values were available in 17 cases diagnosed prior to 22 weeks' gestation and acetylcholinesterase (AF-ACE) values, in 21 cases. All 7 fetuses with a gastroschisis had an elevated AF-AFP, while only 2 of the 10 fetuses with an omphalocele had elevated values (P = .002). ACE was present in 80% of the cases of gastroschisis versus 27.3% of the cases of omphalocele (P = .03). With equivocal sonographic findings, a normal AF-AFP and negative AF-ACE may be more compatible with an omphalocele.

Fused eyelids, airway anomalies, ovarian cysts, and digital abnormalities in siblings: a new autosomal recessive syndrome or a variant of Fraser syndrome?

We describe two siblings of unlike gender born to non-consanguineous parents, with similar and unique congenital malformations. These include fused eyelids, craniofacial anomalies, ovarian cyst, subglottic stenosis, specific digital abnormalities, and no detected chromosomal abnormality. The specific digital abnormalities in both patients are characterized by extension of metacarpophalangeal joints with flexion of the proximal interphalangeal joint of both index fingers with resulting overlap of the second digit over the third. Similar changes were noted in both second toes. The brain weight of both infants was less than that expected for their birth weights. We reviewed the differential diagnosis of fused eyelids, airway anomalies, and ovarian cysts, and the manifestations resemble those seen in Fraser syndrome. We conclude that the dissimilarities warrant considering that our patients have a distinct autosomal recessive syndrome.

Second case report of del(4) (q25q27) and review of the literature.

We report a malformed infant with a de novo interstitial deletion of 4q. This is the second patient reported with del(4) (q25q27). Although there are several common features such as marked hypotonia, cardiac abnormalities, cleft palate, and micrognathia noted in our case and that of Chudley et al. (1988), we conclude from our comparison of the seven previously reported cases involving deletions of bands 4(q25q27) that a specific phenotype cannot yet be described for this deletion.

Polyasplenia complex with mesocardia and renal agenesis in an infant of a diabetic mother.

Despite improved prenatal care, infants of diabetic mothers (IDM) have an increased risk of congenital malformations. We report on an IDM with multiple congenital anomalies consistent with the polyasplenia complex with associated mesocardia and renal agenesis. The morphologic characteristics of these malformations are discussed. Special emphasis is given to the polyasplenia complex as an example of midline developmental field defect. The importance of maternal levels of hemoglobin A1c in relation to congenital malformations is addressed.

Prenatal detection of 46,XY,rec(5),dup q, inv(5)(p13q33) using DNA analysis, flow cytometry, and in situ hybridization to supplement classical cytogenetic analysis.

Distinguishing between balanced and unbalanced chromosome complements segregating from parental rearrangements may be difficult using only classical cytogenetic techniques if banding morphology is similar under both expectations. In these situations, supplementing cytogenetic analysis with molecular genetic techniques and flow cytometry may provide increased diagnostic accuracy. To illustrate this, we present a case in which similar band pattern morphology would be expected for both the balanced carrier (heterozygote) and the recombinant dup q chromosome complements segregating from a mother with a balanced inversion [46,XX,inv(5)(p13q33)]. The parents came to Northwestern for consultation after receiving conflicting interpretations of their first amniotic fluid cultures. An ultrasound examination was said to be normal. They inquired whether there were ways to increase their confidence that the complement was unbalanced. Their reluctance to terminate the pregnancy was due to a 6-year history of infertility. After extensive counselling, the couple elected repeat amniocentesis. Further cytogenetic analysis of repeat amniotic fluid cultures by G-banding and R-banding, molecular genetic analysis with highly polymorphic DNA probes, and quantitative flow cytometry were performed. Results agreed that an unbalanced fetal complement was present. Southern blot analysis with a 5p marker definitively demonstrated a lack of maternal 5p material in the fetus, and in situ hybridization showed a 5q marker at either end of the recombinant chromosome. Flow cytometry was consistent with this interpretation. Because of the advanced gestational age, the parents elected to terminate based on cytogenic results of the second amniocentesis, rather than to wait another 1-2 weeks for results of other methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Management of the fetus with urinary tract dilatation.

This report describes our experience with 18 pregnant women who presented to our center with suspected fetal urinary tract dilatation. The patients were divided into 4 groups: group I had unilateral fetal urinary tract dilatation and normal amniotic fluid volume, group II had bilateral dilatation and normal amniotic fluid volume, group III had bilateral dilatation and oligohydramnios, group IV had nonurinary tract malformations in addition to urinary tract dilatation. Patients with normal amniotic fluid volume and either unilateral or bilateral fetal dilatation (groups I and II) had a good pregnancy outcome. Patients with oligohydramnios and bilateral dilatation had a poor pregnancy outcome. No intrauterine surgery or shunting was performed in any of the patients. The initial diagnosis of urinary tract dilatation led to the prenatal diagnosis of major nonurologic malformations (group IV) in 3 patients who also had a poor outcome. An algorithm is presented that reflects our experience with the management of these patients and could serve as a guide for others caring for similar patients.

Thanatophoric dysplasia and cloverleaf skull.

Nine infants with thanatophoric dysplasia (TD) and cloverleaf skull (CS) are reported. Twenty-two previously published CSTD cases are reviewed. These CSTD cases are compared to cases of TD without CS. It is concluded that there are two types of TD: type 1, with curved femora and very flat vertebral bodies; and type 2, with straight femora and taller vertebral bodies. Consistent but subtle histopathological characteristics differentiate the two types. Only a very few type 1 cases have CS, and the CS is mild. Almost all type 2 cases have severe CS.

Chromatid repulsion associated with Roberts/SC phocomelia syndrome is reduced in malignant cells and not expressed in interspecies somatic-cell hybrids.

Different cell types from a female patient with Roberts/SC phocomelia syndrome were evaluated quantitatively for the presence of repulsion of heterochromatin and satellite regions of mitotic chromosomes. Whereas EBV-transformed lymphoblasts from an established cell line revealed these phenomena at frequencies equal to those in PHA-stimulated lymphocytes and cultured skin fibroblasts, aneuploid cells from a metastatic melanoma displayed them at 50% lower frequency. Cocultivation of the patient's fibroblasts with either an immortal Chinese hamster cell line or with a human male fibroblast strain carrying a t(4;6)(p14;q21) translocation showed that the phenomenon was not corrected or induced by a diffusible factor or by cell-to-cell contact. In each experiment, only the patient's metaphase spreads revealed chromatid repulsion. In fusion hybrids between the patient's fibroblasts and an established Chinese hamster cell line, the human chromosomes behaved perfectly normally, suggesting that the gene product which is missing or mutant in Roberts/SC phocomelia syndrome is supplied by the Chinese hamster genome.

The tricho-rhino-phalangeal syndrome with exostoses (or Langer-Giedion syndrome): four additional patients without mental retardation and review of the literature.

We report on four patients with tricho-rhino-phalangeal syndrome with exostoses (TRPSE) who were not mentally retarded and review 32 previously published cases. These data enable more complete delineation of the phenotype and document the variability of the clinical and radiographic manifestations. Information on the genetics and the association with del(8q) is discussed, as are management and avenues for further investigation. The apparent variability of intelligence in TRPSE patients together with the high incidence of other problems, including significant delay in speech development and hearing loss, make systematic multidisciplinary evaluation and long-term treatment necessary to achieve the best outcome.

Assignment of the gene for cystathionine beta-synthase to human chromosome 21 in somatic cell hybrids.

Among several established mouse, rat, and Chinese hamster cell lines that were screened for cystathionine beta-synthase (CBS) activity, mouse 3T3 and Chinese hamster Don fibroblasts were found to contain no detectable activity. Somatic cell hybrids between human fibroblasts KG-7 with normal CBS activity and Don/a23TK- cells (series XXI) were examined for CBS activity and for human chromosome content. Only chromosome 21 cosegregated with CBS activity. Because the activities measured could represent either Chinese hamster or human gene products, we have prepared a new series of hybrids between Don/a23TK- cells and mutant human fibroblasts from a patient with homocystinuria due to deficiency of functional CBS mRNA. None of these (series XXV) hybrids contained detectable CBS activity, although collectively all human chromosomes were represented. Our results suggest that the human gene for CBS, called CBS, and thus for the most common form of homocystinuria, is located on chromosome 21.