Cochlear implantation in superficial siderosis

Superficial siderosis is a rare central nervous system disorder characterized by deafness, ataxia, and pyramidal signs. The hearing loss is believed to be predominantly neural and is usually progressive and bilateral. Careful assessment is therefore necessary to determine the best approach to hearing rehabilitation. A case is presented of superficial siderosis in a young woman who has benefitted significantly from cochlear implantation using the Nucleus device.

Exclusion of candidate loci and cholesterol biosynthetic abnormalities in familial Pallister-Hall syndrome

Pallister-Hall syndrome (PHS) was originally described in 1980 in six sporadic cases of children with structural anomalies including hypothalamic hamartoma, polydactyly, imperforate anus, and renal and pulmonary anomalies. In 1993, the first familial cases were reported, including affected sibs and vertical transmission. Three of these families are sufficiently large to allow initial evaluation by linkage studies to candidate genes or loci. We have evaluated candidate loci for PHS based on three clinical observations. The first is a patient with PHS-like malformations, including a hypothalamic hamartoma, and an unbalanced translocation involving 7q and 3p. The second is a family with familial PHS where the founder's father had an autosomal dominant hand malformation previously mapped to 17q. The third is the phenotypic overlap of PHS and Smith-Lemli-Opitz syndrome. In this report, we exclude these loci as candidates for linkage to the PHS phenotype on the basis of lod scores of less than-2.0. We conclude that hypothalamic hamartoma is not specific to PHS and that the dominant hand malformation in one of the families was a coincidence. To evaluate the relationship of PHS to Smith-Lemli-Opitz syndrome, we analysed levels of cholesterol and intermediate metabolites of the later stages of cholesterol biosynthesis. There is no evidence of a generalised disorder of cholesterol biosynthesis in patients with familial PHS. On genetic and biochemical grounds, we conclude that PHS and Smith-Lemli-Opitz syndrome are not allelic variants of a single locus.

Posterior rhinoscopy revisited

Posterior rhinoscopy remains a valuable yet often difficult examination by conventional means. Fibreoptics, although providing an excellent alternative, may not always be available. We have combined a St. Clair Thomson's mirror with a Lack's metallic tongue depressor for ease of examination and patient cooperation. It is possible to examine the nasopharynx with 6 mm, 8 mm, 10 mm and 12 mm mirrors. The instrument may be boiled, is sturdy, economical and extremely useful in paediatric practice.

Neurofibromatosis type 1--an update and review for the primary pediatrician

With an incidence of 1 in 3,000, neurofibromatosis type 1 (NF1), or von Recklinghausen disease, is one of the most common genetic disorders encountered by primary care physicians. NF1 is a multisystem disease that affects more than one million people worldwide (more than 80,000 in the United States). Although most pediatricians have patients with NF1 in their practices, many affected individuals go undiagnosed as children. This article is intended to facilitate the diagnosis and management of young patients with NF1.

Evaluation and treatment of the deformed and malformed auricle

Auricular malformations begin within the first few weeks of intrauterine growth. Less severe deformational abnormalities occur from abnormal fetal positioning. They can be corrected early after birth by simple reshaping and molding. No longer should the pediatrician wait for minor deformities to resolve spontaneously. The protruding ear may not be present at birth but may develop and worsen during the first year. The most severe anomalies require complex multistage reconstructions after other concomitant anomalies are excluded. The pediatrician must be an integral part of this reconstructive team.

Pallister-Hall syndrome

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A novel method for the rapid separation of plasma lipoproteins using self-generating gradients of iodixanol

We describe a new method for the rapid fractionation of plasma lipoproteins, which makes use of a new non-ionic, iodinated, density gradient medium, iodixanol, commercially available as Optiprep(TM). The method is simple: plasma or serum is mixed with iodixanol followed by centrifugation in a vertical or near vertical rotor. Separation of VLDL, LDL and HDL can be achieved in 3 h and the lipoprotein fractions are comparable in density and composition with those prepared using conventional salt based gradients. Each class of lipoprotein can be removed in a single fraction, or a profile of lipoprotein distribution can be obtained using a gradient fractionator. Because the medium is inert, fractions from the gradient can be analysed by agarose gel electrophoresis or assayed for lipid content or apolipoprotein composition by SDS-PAGE without removing the iodixanol. Small differences in electrophoretic mobility of HDL and LDL across several gradient fractions suggest that subfractionation of these classes may occur. The new method is simple, rapid and versatile with potential application for preparation of lipoproteins and for analysis of lipoprotein profiles in the research or clinical laboratory.

FGFR2 exon IIIa and IIIc mutations in Crouzon, Jackson-Weiss, and Pfeiffer syndromes: evidence for missense changes, insertions, and a deletion due to alternative RNA splicing

Fibroblast growth factor receptor 2 (FGFR2) mutations have been associated with the craniosynostotic conditions Crouzon, Jackson-Weiss, and Pfeiffer syndromes. Previously, mutations were described in the exons IIIa and IIIc, which form the extracellular, third immunoglobulin-like domain (IgIII) and adjacent linker regions, both of which are normally involved in ligand binding. For all three conditions, mutations were found in exon IIIc. Only in Crouzon syndrome were mutations identified in exon IIIa. In this study, 39 cases with one of these three conditions were screened for exon IIIa or IIIc mutations. Eleven mutations are reported in 17 unrelated cases. Mutations in exon IIIa are identified for not only Crouzon but also Jackson-Weiss and Pfeiffer syndromes. Four mutations in either exon IIIa or exon IIIc reported only in Crouzon syndrome are present also in one of the other two syndromes. Two insertions, one in exon IIIa in a Crouzon syndrome patient and the other in exon IIIc in a Pfeiffer syndrome patient, were observed. The latter mutation has the same alternative RNA splicing effect as a reported synonymous mutation for Crouzon syndrome. A missense mutation was detected in one Pfeiffer syndrome family in which two members had craniosynostosis without limb anomalies. The inter- and intrafamilial variability in expression of FGFR2 mutations suggests that these three syndromes, presumed to be clinically distinct, are instead representative of a spectrum of related craniosynostotic and digital disorders.

Transient leukemia with trisomy 21: description of a case and review of the literature

Transient myeloproliferative disease (TMD) is often associated with a trisomy 21 cell line, but it is not always associated with clinical signs of Down syndrome. We report on a phenotypically normal newborn boy who presented with a high white blood cell count, undifferentiated blasts, and cutaneous leukemic infiltrates and compare this patient with the literature on TMD and trisomy 21. Chromosome analysis of bone marrow, and subsequently of skin fibroblasts, documented constitutional mosaicism for trisomy 21. A decrease in the frequency of blast cells paralleled a decrease in cells demonstrating trisomy 21 in hematopoietic tissues, and a complete clinical recovery was seen without the use of chemotherapy. Recognition of this transient form of congenital leukemia is important to prevent the unnecessary use of toxic chemotherapeutic agents in such patients.

Clinical and molecular studies in full trisomy 22: further delineation of the phenotype and review of the literature

Trisomy 22 is commonly found among spontaneous abortions, second in frequency of occurrence only to trisomy 16. Most earlier reports of surviving trisomy 22 cases in the literature are thought to represent the product of unbalanced 11;22 translocations or the result of undetected mosaicism, since this condition is thought to manifest early embryonic or fetal lethality. We present two strikingly similar cases of non-mosaic trisomy 22 surviving to late gestation. In this paper we emphasize the unique phenotype of this trisomy which included intrauterine growth retardation, microcephaly, broad flat nasal bridge with epicanthal folds and ocular hypertelorism, microtia, variable cleft palate, webbed neck, congenital heart defects involving anomalous great vessels, anorectal and renal anomalies, and hypoplastic distal digits with thumb anomalies. We also explore why some cases survive to late gestation. Confined placental mosaicism, a frequent finding in other lethal trisomies, has been ruled out in one of the cases. Molecular studies done to assess the parental origin of the extra chromosome in the other case showed that the non-disjunction originated during maternal meiosis II. Parental origin of the extra chromosome does not seem to play a role in late survival for trisomy 22.

Longitudinal observations on 15 children with Wiedemann-Beckwith syndrome

We conducted a follow-up study on 15 patients with Wiedemann-Beckwith syndrome (WBS) to further clarify major and minor diagnostic clinical characteristics and longterm expectations for growth and development. We found patients with WBS tended to have polyhydramnios with large placentas which were almost twice normal placental weight. The large fetal size and polyhydramnios often resulted in early delivery with occasional perinatal mortality (three cases). Increased placental size, with associated polyhydramnios resulting in excessive umbilical cord length, may be useful in suspecting WBS prior to delivery, thereby facilitating perinatal management. The presence of abdominal wall defects and/or macroglossia may help to confirm the diagnosis. At birth, patients were almost 2 standard deviations above the expected mean for gestational age, length, and weight. This trend continued through early childhood and then excessive size became less dramatic with increasing age. We detected no cytogenetic variations in nine patients who had studies done and, to date, no tumors have been detected other than a gastric teratoma that was evident in one infant at birth. Longitudinally, the children have not had an unusual incidence of medical problems, and long-term ultrasound monitoring was not burdensome to the families. In comparison, mental and social development to unaffected siblings and cousins appeared normal.

Clinical and molecular characterization of patients with distal 11q deletions

Jacobsen syndrome is caused by segmental aneusomy for the distal end of the long arm of chromosome 11. Typical features include mild to moderate psychomotor retardation, trigonocephaly, facial dysmorphism, cardiac defects, and thrombocytopenia, though none of these features are invariably present. To define the critical regions responsible for these abnormalities, we studied 17 individuals with de novo terminal deletions of 11q. The patients were characterized in a loss-of-heterozygosity analysis using polymorphic dinucleotide repeats. The breakpoints in the complete two-generation families were localized with an average resolution of 3.9 cM. Eight patients with the largest deletions extending from 11q23.3 to 11qter have breakpoints, between D11S924 and D11S1341. This cytogenetic region accounts for the majority of 11q- patients and may be related to the FRA11B fragile site in 11q23.3. One patient with a small terminal deletion distal to D11S1351 had facial dysmorphism, cardiac defects, and thrombocytopenia, suggesting that the genes responsible for these features may lie distal to D11S1351. Twelve of 15 patients with deletion breakpoints as far distal as D11S1345 had trigonocephaly, while patients with deletions distal to D11S912 did not, suggesting that, if hemizygosity for a single gene is responsible for this dysmorphic feature, the gene may lie distal to D11S1345 and proximal to D11S912.

A prospective randomised trial of the use of sodium bicarbonate and hydrogen peroxide ear drops to clear a blocked tympanostomy tube

This randomised prospective trial compared the efficacy of sodium bicarbonate and hydrogen peroxide ear drops in clearing a blocked tympanostomy tube. Tympanostomy tubes, 110 in number, obstructed with blood or inspissated secretions were randomised into treatment and control groups. Details of the operative procedure were retrospectively collected from the patients notes. The patients were reviewed after 2 weeks for both clinical and tympanometric evidence of clearance of the tube and evidence of complications of the drops. There was no significant therapeutic advantage between the two drops (P > 0.9), but in both treatment arms there was a significant therapeutic advantage over a period of observation (P < 0.05 in both groups). Otorrhoea and pain on instilling the drops occurred with equal incidence in both treatment groups. As obstruction of tympanostomy tubes is a common occurrence which often prompts surgical reventilation, there is great potential for cost savings if conservative treatment can be used effectively. The treatments for obstructed tympanostomy tubes are reviewed and methods of prevention of this common occurrence are discussed.

Familial Pallister-Hall syndrome

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Nonorganic hearing loss in cochlear implant candidates

Five patients undergoing assessment for cochlear implantation have been found to have a nonorganic hearing loss (pseudohypacusis). This phenomenon has not been reported previously in this patient population. The cases are presented and the causes, detection, and management of this condition are discussed.

Mixoploidy in humans: two surviving cases of diploid-tetraploid mixoploidy and comparison with diploid-triploid mixoploidy

We report on 2 cases of diploid/tetraploid (2n/4n) mixoploidy in surviving females, 11 and 21 years old. Both individuals manifested severe mental retardation, reduced peripheral limb muscle bulk, asymmetric growth deficiency, seizure disorder, and skin pigmentary dysplasia. Previous lymphocyte karyotypes had been normal on 2 occasions, but when skin fibroblast karyotypes were done, 33% of the cells were tetraploid on the younger woman, and over 60% were tetraploid in the older woman (on 2 separate occasions). In both individuals, the distal limbs and digits were long and thin, with reduced small muscle bulk. The similarity in distal limb findings prompted reexamination of the younger woman's chromosomal constitution in skin fibroblasts. We concluded that the clinical findings in these cases are unique and similar, and we caution clinicians about uniformly dismissing tetraploidy as artifactual in amniocytes from normal patients, especially since this phenotype would be very difficult to detect, even with directed prenatal ultrasonography. We compare the 2n/4n phenotype with that in diploid/triploid (2n/3n) mixoploidy and note subtle differences which might be detected postnatally. These findings should be useful in guiding clinicians on when to request skin fibroblast karyotypes in mentally-deficient individuals with asymmetric growth deficiency and pigmentary skin variation.

Formal reintubation for incipient neonatal subglottic stenosis

In a small prospective series of 10 children who presented with incipient subglottic stenosis following neonatal intubation a protocol of formal reintubation for two weeks, with sedation, enabled six of the children to avoid tracheostomy or other forms of surgery and in the remaining four it is unlikely that the trial of reintubation made the degree of laryngeal and subglottic damage worse.

Trisomy 8 mosaicism in chorionic villus sampling: case report and counselling issues

We report an unusual case involving chorionic villus sampling (CVS) and trisomy 8 mosaicism. CVS showed a normal direct preparation while the culture showed mosaicism for trisomy 8. Subsequent amniocentesis revealed only normal chromosomes. A peripheral blood culture after birth revealed low-level trisomy 8 mosaicism. The patient appeared phenotypically and developmentally normal at 30 months of age. We conclude that prenatal counselling for similar cases needs to include the rare but real possibility that chromosome mosaicism detected prenatally may be found postnatally with largely unknown consequences. Secondly, low-level chromosomal mosaicism may be more common than previously recognized. Thirdly, very low-level trisomy 8 mosaicism may be compatible with a normal phenotype but long-term follow-up is required. And lastly, the use of fetal blood sampling is questionable in these cases because the phenotype may not be accurately predicted. Further studies of such cases are needed to address these important and unanswered issues, including the potential implication of mosaicism on academic performance and cognitive functioning.

Prenatal diagnosis and dysmorphic findings in mosaic trisomy 16

We report two cases of mosaic trisomy 16 diagnosed by amniocentesis, with dysmorphic findings in both cases evident upon delivery. Following elective termination, case 1 demonstrated a trisomy 16 cell line in fetal skin (4 per cent) and placental tissue (64 per cent). Molecular studies on the disomic cell line indicated that both chromosome 16s were maternal in origin, suggesting loss of the paternal chromosome 16 from a trisomic zygote (uniparental heterodisomy). At birth, case 2 demonstrated only disomic cells in skin and blood, with trisomy 16 present in 4 per cent of cells from the amnion. Molecular studies confirmed both maternal and paternal contributions of the chromosome 16s. We analysed DNA from one previously reported case of mosaic trisomy 16 (Williams et al., 1992) and failed to find signs of uniparental disomy in this child with congenital heart defects. These cases had distinctive but different dysmorphic features. We suggest that trisomy 16 embryos may revert to disomy during the course of pregnancy, allowing for longer survival with various abnormalities in growth and morphogenesis. The clinical significance of prenatally detected mosaic trisomy 16 may not be completely defined by additional cytogenetic, molecular, and ultrasound studies.

Endometritis after cesarean: the effect of age

In this study, we compared the rate of endometritis after cesarean section in two age groups. The first group consisted of patients who were 17 years old or younger (teenage group) and the second group of patients were 35 years of age or older (advanced maternal age group). Patients in each group were matched for length of labor, length of rupture of membranes, and the use of prophylactic antibiotics. In the teenage group, 18 of 41 (43.9%) developed endometritis compared with 6 of 41 (14.6%) in the advanced maternal age group (P < 0.003). This study supports the concept that young age is a risk factor for endometritis after cesarean section.