Dose-dependent expression of claudin-5 is a modifying factor in schizophrenia

Schizophrenia is a neurodevelopmental disorder that affects up to 1% of the general population. Various genes show associations with schizophrenia and a very weak nominal association with the tight junction protein, claudin-5, has previously been identified. Claudin-5 is expressed in endothelial cells forming part of the blood-brain barrier (BBB). Furthermore, schizophrenia occurs in 30% of individuals with 22q11 deletion syndrome (22q11DS), a population who are haploinsufficient for the claudin-5 gene. Here, we show that a variant in the claudin-5 gene is weakly associated with schizophrenia in 22q11DS, leading to 75% less claudin-5 being expressed in endothelial cells. We also show that targeted adeno-associated virus-mediated suppression of claudin-5 in the mouse brain results in localized BBB disruption and behavioural changes. Using an inducible 'knockdown' mouse model, we further link claudin-5 suppression with psychosis through a distinct behavioural phenotype showing impairments in learning and memory, anxiety-like behaviour and sensorimotor gating. In addition, these animals develop seizures and die after 3-4 weeks of claudin-5 suppression, reinforcing the crucial role of claudin-5 in normal neurological function. Finally, we show that anti-psychotic medications dose-dependently increase claudin-5 expression in vitro and in vivo while aberrant, discontinuous expression of claudin-5 in the brains of schizophrenic patients post mortem was observed compared to age-matched controls. Together, these data suggest that BBB disruption may be a modifying factor in the development of schizophrenia and that drugs directly targeting the BBB may offer new therapeutic opportunities for treating this disorder.

Social cognitive training in adolescents with chromosome 22q11.2 deletion syndrome: feasibility and preliminary effects of the intervention

BACKGROUND

Children with chromosome 22q11.2 deletion syndrome (22q11DS) often have deficits in social cognition and social skills that contribute to poor adaptive functioning. These deficits may be of relevance to the later occurrence of serious psychiatric illnesses such as schizophrenia. Yet, there are no evidence-based interventions to improve social cognitive functioning in children with 22q11DS.

METHODS

Using a customised social cognitive curriculum, we conducted a pilot small-group-based social cognitive training (SCT) programme in 13 adolescents with 22q11DS, relative to a control group of nine age- and gender-matched adolescents with 22q11DS.

RESULTS

We found the SCT programme to be feasible, with high rates of compliance and satisfaction on the part of the participants and their families. Our preliminary analyses indicated that the intervention group showed significant improvements in an overall social cognitive composite index.

CONCLUSIONS

SCT in a small-group format for adolescents with 22q11DS is feasible and results in gains in social cognition. A larger randomised controlled trial would permit assessment of efficacy of this promising novel intervention.

A tale worth telling: the impact of the diagnosis experience on disclosure of genetic disorders

BACKGROUND

Research suggests children with genetic disorders exhibit greater coping skills when they are aware of their condition and its heritability. While the experiences parents have at diagnosis may influence their decision to disclose the diagnosis to their children, there is little research into this communication. The aim of the current study was to examine the relationship between the diagnosis experience and the disclosure experience for parents of children with developmental disorders of a known genetic aetiology: parents of children with 22q11.2 deletion syndrome (22q11DS) were compared with a group of parents with children affected with other genetic diagnoses, with a similar age of diagnosis (e.g. fragile X syndrome) and a group where diagnosis generally occurs early (i.e. Down syndrome).

METHOD

The sample comprised 559 parents and caregivers of children with genetic developmental disorders, and an online survey was utilised. Items from the questionnaire were combined to create variables for diagnosis experience, parental disclosure experience, child's disclosure experience, and parental coping and self-efficacy.

RESULTS

Across all groups parents reported that the diagnosis experience was negative and often accompanied by a lack of support and appropriate information. Sixty-eight per cent of those in the 22q11DS and 58.3% in the Similar Conditions groups had disclosed the diagnosis to their child, whereas only 32.7% of the Down syndrome group had. Eighty-six per cent of the Down syndrome group felt they had sufficient information to talk to their child compared with 44.1% of the Similar Conditions group and 32.6% of the 22q11DS group. Parents reported disclosing the diagnosis to their child because they did not want to create secrets; and that they considered the child's age when disclosing. In the 22q11DS and Similar Conditions groups, a poor diagnosis experience was significantly associated with negative parental disclosure experiences. In the Similar Conditions group, a poor diagnosis experience was also significantly associated with a more negative child disclosure experience.

CONCLUSIONS

As expected this study highlights how difficult most parents find the diagnosis experience. Importantly, the data indicate that the personal experiences the parents have can have a long-term impact on how well they cope with telling their child about the diagnosis. It is important for clinicians to consider the long-term ramifications of the diagnosis experience and give the parents opportunities; through, for instance, psychoeducation to prepare for telling their child about the diagnosis. Further research is warranted to explore what type of information would be useful for parents to receive.

Practical considerations in the clinical application of whole-exome sequencing

Despite the exciting advent of whole-exome sequencing (WES) in medical genetics practices, the optimal interpretation of results requires further actions such as reconsidering clinical information and obtaining further laboratory testing. There are no published data to guide clinicians in this process. In a retrospective study on 93 patients who underwent clinical WES, we set out to assess and resolve these practical challenges. With the laboratories reporting a molecular diagnostic rate of 25.8%, the medical geneticists and the laboratories were 90% concordant in their interpretation of the WES results. Divergence occurred when the medical geneticist reconsidered clinical information and/or additional information regarding pathogenicity of a variant. Variants of uncertain significance were reported in 86% of patients, with 53.7% needing follow-up, such as additional laboratory tests and genotyping of family members. By layering clinical data (e.g. mode of inheritance and phenotypic fit) on to the laboratory results, we developed clinical categories for the WES results. These categories of definite diagnosis (14/93), likely diagnosis (8/93), possible diagnosis (13/93) and no diagnosis (58/93) could be used to convey results to patients uniformly. Our framework for a clinically informed interpretation of the results enhances the utility of WES within medical genetics practices.

The RBMX gene as a candidate for the Shashi X-linked intellectual disability syndrome

A novel X-linked intellectual disability (XLID) syndrome with moderate intellectual disability and distinguishing craniofacial dysmorphisms had been previously mapped to the Xq26-q27 interval. On whole exome sequencing in the large family originally reported with this disorder, we identified a 23 bp frameshift deletion in the RNA binding motif protein X-linked (RBMX) gene at Xq26 in the affected males (n = 7), one carrier female, absent in unaffected males (n = 2) and in control databases (7800 exomes). The RBMX gene has not been previously causal of human disease. We examined the genic intolerance scores for the coding regions and the non-coding regions of RBMX; the findings were indicative of RBMX being relatively intolerant to loss of function variants, a distinctive pattern seen in a subset of XLID genes. Prior expression and animal modeling studies indicate that loss of function of RBMX results in abnormal brain development. Our finding putatively adds a novel gene to the loci associated with XLID and may enable the identification of other individuals affected with this distinctive syndrome.

Association of the family environment with behavioural and cognitive outcomes in children with chromosome 22q11.2 deletion syndrome

BACKGROUND

Children with 22q11.2 deletion syndrome (22q11DS) are at risk for social-behavioural and neurocognitive sequelae throughout development. The current study examined the impact of family environmental characteristics on social-behavioural and cognitive outcomes in this paediatric population.

METHOD

Guardians of children with 22q11DS were recruited through two medical genetics clinics. Consenting guardians were asked to complete several questionnaires regarding their child's social, emotional and behavioural functioning, as well as family social environment and parenting styles. Children with 22q11DS were asked to undergo a cognitive assessment, including IQ and achievement testing, and measures of attention, executive function and memory.

RESULTS

Modest associations were found between aspects of the family social environment and parenting styles with social-behavioural and cognitive/academic outcomes. Regression models indicated that physical punishment, socioeconomic status, parental control and family organisation significantly predicted social-behavioural and cognitive outcomes in children with 22q11DS.

CONCLUSION

Characteristics of the family social environment and parenting approaches appear to be associated with functional outcomes of children with 22q11DS. Understanding the impact of environmental variables on developmental outcomes can be useful in determining more effective targets for intervention. This will be important in order to improve the quality of life of individuals affected by 22q11DS.

Evaluation of Clinical Manifestations in Patients with Severe Lymphedema with and without CCBE1 Mutations

The lymphedema-lymphangiectasia-intellectual disability (Hennekam) syndrome (HS) is characterised by a widespread congenital lymph vessel dysplasia manifesting as congenital lymphedema of the limbs and intestinal lymphangiectasia, accompanied by unusual facial morphology, variable intellectual disabilities and infrequently malformations. The syndrome is heterogeneous as mutations in the gene CCBE1 have been found responsible for the syndrome in only a subset of patients. We investigated whether it would be possible to predict the presence of a CCBE1 mutation based on phenotype by collecting clinical data of patients diagnosed with HS, with or without a CCBE1 mutation. We report here the results of 13 CCBE1 positive patients, 16 CCBE1 negative patients, who were clinically found to have classical HS, and 8 patients in whom the diagnosis was considered possible, but not certain, and in whom no CCBE1 mutation was identified. We found no statistically significant phenotypic differences between the 2 groups with the clinical HS phenotype, although the degree of lymphatic dysplasia tended to be more pronounced in the mutation positive group. We also screened 158 patients with less widespread and less pronounced forms of lymphatic dysplasia for CCBE1 mutations, and no mutation was detected in this group. Our results suggest that (1) CCBE1 mutations are present only in patients with a likely clinical diagnosis of HS, and not in patients with less marked forms of lymphatic dysplasia, and (2) that there are no major phenotypic differences between HS patients with or without CCBE1 mutations.

Social skills and associated psychopathology in children with chromosome 22q11.2 deletion syndrome: implications for interventions

BACKGROUND

Although distinctive neuropsychological impairments have been delineated in children with chromosome 22q11 deletion syndrome (22q11DS), social skills and social cognition remain less well-characterised.

OBJECTIVE

To examine social skills and social cognition and their relationship with neuropsychological function/behaviour and psychiatric diagnoses in children with 22q11DS.

METHODS

Sixty-six children with 22q11DS and 54 control participants underwent neuropsychological testing and were administered the Diagnostic Analysis of Non-Verbal Accuracy (DANVA) for face and auditory emotion recognition, a measure of social cognition: their parents/guardians were administered the Social Skills Rating System (SSRS) - parent version, Child Behavior Checklist (CBCL) - parent version and the Computerised Diagnostic Interview Schedule for Children (C-DISC).

RESULTS

The 22q11DS group exhibited significantly lower social skills total score and more problem social behaviours, lower neurocognitive functioning, higher rates of anxiety disorders and more internalising symptoms than the control group. Participants with 22q11DS also exhibited significant deficits in their ability to read facial expressions compared with the control group, but performed no differently than the control participants in the processing of emotions by tone of voice. Within the 22q11DS group, higher social competency was correlated with higher global assessment of functioning and parental socio-economic status. Social competency was worse in those with anxiety disorders, attention deficit hyperactivity disorder, more than two psychiatric diagnoses on the C-DISC and higher internalising symptoms. No significant correlations of SSRS scores were seen with IQ, executive functions, attention, or verbal learning and memory. No correlations were found between social cognition and social skill scores.

CONCLUSION

Our results indicate that social skills in children with 22q11DS are associated with behaviour/emotional functioning and not with neurocognition. Thus, treating the behaviour or emotional problems such as attention deficit hyperactivity disorder and anxiety disorders may provide a pathway for improving social skills in these children.

Dysregulation of DGCR6 and DGCR6L: psychopathological outcomes in chromosome 22q11.2 deletion syndrome

Chromosome 22q11.2 deletion syndrome (22q11DS) is the most common microdeletion syndrome in humans. It is typified by highly variable symptoms, which might be explained by epigenetic regulation of genes in the interval. Using computational algorithms, our laboratory previously predicted that DiGeorge critical region 6 (DGCR6), which lies within the deletion interval, is imprinted in humans. Expression and epigenetic regulation of this gene have not, however, been examined in 22q11DS subjects. The purpose of this study was to determine if the expression levels of DGCR6 and its duplicate copy DGCR6L in 22q11DS subjects are associated with the parent-of-origin of the deletion and childhood psychopathologies. Our investigation showed no evidence of parent-of-origin-related differences in expression of both DGCR6 and DGCR6L. However, we found that the variability in DGCR6 expression was significantly greater in 22q11DS children than in age and gender-matched control individuals. Children with 22q11DS who had anxiety disorders had significantly lower DGCR6 expression, especially in subjects with the deletion on the maternal chromosome, despite the lack of imprinting. Our findings indicate that epigenetic mechanisms other than imprinting contribute to the dysregulation of these genes and the associated childhood psychopathologies observed in individuals with 22q11DS. Further studies are now needed to test the usefulness of DGCR6 and DGCR6L expression and alterations in the epigenome at these loci in predicting childhood anxiety and associated adult-onset pathologies in 22q11DS subjects.

Cognitive correlates of a functional COMT polymorphism in children with 22q11.2 deletion syndrome

Chromosome 22q11.2 deletion syndrome (22q11DS) is a common microdeletion syndrome associated with a markedly elevated risk of schizophrenia in adulthood. Cognitive impairments such as a low IQ and deficits in attention and executive function are common in childhood. The catechol O-methyltransferase (COMT) gene maps within the deleted region and is involved in the degradation of dopamine, a neurotransmitter thought to be important in cognition and the development of schizophrenia. Thus, we examined the correlation between neurocognitive deficits and a common polymorphism Val(158)Met in the COMT gene in a cohort of children with 22q11DS. Our results show that children with 22q11DS who have the Met allele have higher IQ and achievement scores and perform better on measures of prefrontal cognition, such as the Continuous Performance Task, as compared with those with the Val allele. These results confirm that the hemizygous COMT Val(158)Met genotype impacts upon cognition in children with 22q11DS.

Ring chromosome 17: phenotype variation by deletion size

Ring chromosome 17 is a rare cytogenetic abnormality, with 12 previous reports in the literature. Some have a relatively mild phenotype characterized by seizures, mental retardation, skin changes and short stature. Other patients have Miller-Dieker syndrome (MDS), which includes lissencephaly, multiple dysmorphic features, severe mental retardation and shortened life expectancy. We describe two new cases of ring chromosome 17 and review the literature. Our cases and the other reports of patients without a deletion encompassing the Miller-Dieker region, delineate a fairly distinctive subgroup of individuals with ring 17, whose phenotype consists of growth and mental retardation, seizures, minor dysmorphic features, café-au-lait spots and retinal flecks. This classification of ring 17 into two distinct groups based on the size of the deletion and the phenotypic manifestations should facilitate clinical suspicion of this rare chromosomal abnormality.

Prenatal diagnosis of complete sole trisomy 1q

The prenatal diagnosis of a complete trisomy of the long arm of chromosome 1 is reported. Major ultrasound findings included: nuchal thickening, bi-temporal narrowing, a single choroid plexus cyst, and mild ventriculomegaly. There was a mass in the chest and abdomen, pleural effusion, ascites and a hyperechoic bowel. Skin edema was present. The fetus died at 26 weeks' gestation. A literature review is presented of 17 de novo and two inherited cases with only trisomy 1q. Of note is the fact that 3/5 prenatally detected 1q trisomies have teratomas. A review of the literature reveals a dismal outcome for trisomy 1q cases if the duplication involves bands 1q25-->q32.

Maternal homozygosity for the common MTHFR mutation as a potential risk factor for offspring with limb defects

A common mutation, C677T, in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene leads to altered homocysteine metabolism, and has been associated with the occurrence of neural tube defects (NTD). Administration of folic acid decreases this risk. There is also evidence that periconceptional supplementation of mothers with folic acid can decrease the risk of limb defects in the offspring. Here we describe a child with a transverse terminal defect of one hand, whose mother is homozygous for the C677T MTHFR mutation. We suggest that homozygosity for the MTHFR mutation may be a risk factor for transverse terminal limb defect/s by an effect mediated through altered folate and homocysteine metabolism. Further studies of mothers of infants with limb reduction defects for the MTHFR mutation may be of help in establishing this association. A simple intervention in the form of folic acid supplementation would be protective, should an association be established.

A unique form of mental retardation with a distinctive phenotype maps to Xq26-q27

We report a novel X-linked mental retardation (XLMR) syndrome, with characteristic facial dysmorphic features, segregating in a large North Carolina family. Only males are affected, over four generations. Clinical findings in the seven living affected males include a moderate degree of mental retardation (MR), coarse facies, puffy eyelids, narrow palpebral fissures, prominent supraorbital ridges, a bulbous nose, a prominent lower lip, large ears, obesity, and large testicles. Cephalometric measurements suggest that the affected males have a distinctive craniofacial skeletal structure, when compared with normative measures. Obligate-carrier females are unaffected with MR, but the results of cephalometric skeletal analysis suggest craniofacial dysmorphisms intermediate between affected males and normative control individuals. Unaffected male relatives show no clinical or cephalometric resemblance to affected males. The blood-lymphocyte karyotype and the results of DNA analysis for fragile-X syndrome and of other routine investigations are normal. Linkage analysis for polymorphic DNA markers spanning the X chromosome established linkage to Xq26-q27. Maximum LOD scores were obtained at marker DXS1047 (maximum LOD score = 3.1 at recombination fraction 0). By use of haplotype analysis, we have localized the gene for this condition to an 18-cM genetic interval flanked by ATA59C05 and GATA31E08. On the basis of both the clinical phenotype and the mapping data, we were able to exclude other reported XLMR conditions. Therefore, we believe that a unique recessive XLMR syndrome with a distinctive and recognizable phenotype is represented in this family.

Partial duplication of 4q12q13 leads to a mild phenotype

We report on the second case of duplication (4)(q12q13) with microcephaly, mental retardation, and minor facial anomalies. Duplications involving the distal region of chromosome 4q are well described and share common clinical findings. However, phenotypic abnormalities of duplications of the proximal portion of chromosome 4q are relatively unknown. A comparison of the clinical manifestations of our patient and the single published case suggests that the phenotype of this proximal 4q duplication is relatively mild. This study emphasizes the need to perform chromosome analysis in similar mildly affected/nonspecific cases.

Genetic heterogeneity of gingival fibromatosis on chromosome 2p

Gingival fibromatosis (GF) occurs in several genetic forms as a simple Mendelian trait, in malformation syndromes, and in some chromosomal disorders. Specific genes responsible for GF have not been identified. An autosomal dominant form of hereditary gingival fibromatosis (HGF, MIM 135300) was recently mapped to chromosome 2p21 in a large Brazilian family and there was an earlier report of GF in a boy with a cytogenetic duplication involving 2p13-->p21. We thus hypothesised that a common gene locus may be responsible for GF in both the Brazilian family and the boy with the chromosome 2p duplication. We performed additional genetic linkage studies on the Brazilian family and molecular cytogenetic studies on the patient with the cytogenetic duplication to correlate more precisely the genetic interval of the HGF phenotype with the duplicated 2p interval. Additional linkage analysis of new family members resulted in refinement of the candidate region for HGF to an 8 Mb region. Molecular cytogenetic analysis of the 2p13-->p21 duplication associated with GF showed that the duplicated region was proximal to the candidate interval for HGF. Thus, our results support the presence of two different gene loci on chromosome 2p that are involved in GF.

Water intoxication in a patient with the Prader-Willi syndrome treated with desmopressin for nocturnal enuresis

PURPOSE

We report on a girl with the Prader-Willi syndrome who received desmopressin for nocturnal enuresis, and water intoxication developed after she ingested a large amount of fluid.

MATERIALS AND METHODS

The patient received 10 mg. desmopressin at bedtime for enuresis. She was hospitalized when a major motor seizure and coma (Glasgow coma scale 8) occurred after ingesting 48 ounces of fluid. Treatment included 3% saline, followed by 5% dextrose in water and sodium chloride given intravenously.

RESULTS

Serum sodium increased to 128 mEq./l. and serum glucose remained normal. Computerized tomography and magnetic resonance imaging of the head were normal and revealed no evidence of cerebral pontine myelinosis. Patient consciousness returned to normal by day 5 after the seizure.

CONCLUSIONS

In patients treated with desmopressin the risk of a seizure or altered level of consciousness can be minimized by not ingesting large quantities of fluid. We recommend that patients drink no more than 8 ounces of fluid on any evening that desmopressin is administered.

Molecular analysis of recombination in a family with Duchenne muscular dystrophy and a large pericentric X chromosome inversion

It has been demonstrated in animal studies that, in animals heterozygous for pericentric chromosomal inversions, loop formation is greatly reduced during meiosis. This results in absence of recombination within the inverted segment, with recombination seen only outside the inversion. A recent study in yeast has shown that telomeres, rather than centromeres, lead in chromosome movement just prior to meiosis and may be involved in promoting recombination. We studied by cytogenetic analysis and DNA polymorphisms the nature of meiotic recombination in a three-generation family with a large pericentric X chromosome inversion, inv(X)(p21.1q26), in which Duchenne muscular dystrophy (DMD) was cosegregating with the inversion. On DNA analysis there was no evidence of meiotic recombination between the inverted and normal X chromosomes in the inverted segment. Recombination was seen at the telomeric regions, Xp22 and Xq27-28. No deletion or point mutation was found on analysis of the DMD gene. On the basis of the FISH results, we believe that the X inversion is the mutation responsible for DMD in this family. Our results indicate that (1) pericentric X chromosome inversions result in reduction of recombination between the normal and inverted X chromosomes; (2) meiotic X chromosome pairing in these individuals is likely initiated at the telomeres; and (3) in this family DMD is caused by the pericentric inversion.

Constellation of congenital abnormalities in an infant: a new syndrome or tissue-specific mosaicism for trisomy 18?

A newborn infant born to consanguineous (first cousin) parents was noted to have complex congenital heart defect and minor anomalies suggestive of trisomy 18. Blood lymphocyte and skin fibroblast karyotypes were normal. He died in the neonatal period of postoperative complications. On interphase fluorescence in-situ hybridization (FISH) using autopsy specimens, a significant number of cells in the liver (17%) were trisomic for chromosome 18, compared to normal control liver tissue. However, interphase FISH analyses of blood lymphocytes, skin fibroblasts, and kidney tissue were normal. It is our opinion that this apparent mosaicism for trisomy 18 in the patient's liver may be spurious, though it brings into focus the issue of possible tissue/organ-specific mosaicism. The anomalies in this infant do not resemble a previously described malformation syndrome. Parental consanguinity raises the possibility that this represents a new autosomal recessive malformation syndrome.

Ovarian granulosa cell tumors with bizarre nuclei: an immunohistochemical analysis with fluorescence in situ hybridization documenting trisomy 12 in the bizarre component [corrected]

Granulosa cell tumors with bizarre nuclei (GCT-BN) are rare lesions with a prognosis apparently similar to that of conventional granulosa cell tumors (GCT-NOS). The immunohistochemical features of GCT-BN have not been described, and the exact nature of the bizarre nuclei (BN) is unclear. Thirteen GCT-BN were studied with antibodies to cytokeratin, vimentin, epithelial membrane antigen, muscle-specific actin, alpha smooth muscle actin, desmin, and S-100 protein. Six cases were also examined by fluorescence in situ hybridization for trisomy 12, a nonrandom chromosomal aberration found in a proportion of ovarian sex-cord stromal tumors. Histologically, 12 tumors (86%) contained BN areas interspersed with large areas of GCT-NOS. The remaining tumor contained only microscopic foci of GCT-NOS. Immunohistochemically, the tumors stained for vimentin (13 tumors), S-100 protein (11 tumors), muscle-specific actin (10 tumors), cytokeratin (eight tumors), alpha smooth muscle actin (eight tumors), and desmin (one tumor), but none stained for epithelial membrane antigen. Immunostaining results for the BN and GCT-NOS areas were concordant in eight (73%) of the 11 tumors in which both areas could be independently assessed. The remaining three tumors (27%) showed discordant results for only one of the eight markers used. In five patients, trisomy 12 was detected by fluorescence in situ hybridization in areas of BN but not in areas of GCT-NOS present in the same tumor. Trisomy 12 was also present in another BN tumor in which the foci of GCT-NOS were too small to be evaluated. We conclude that within GCT-BN, areas with BN are immunohistochemically similar to areas of GCT-NOS present in the same tumor. The finding of trisomy 12 in areas with BN but not GCT-NOS in the same tumor, however, suggests that cells with BN represent a genetically distinct clone of tumor cells arising within GCT-NOS.

Vascular ring leading to tracheoesophageal compression in a patient with Rubinstein-Taybi syndrome

Mediastinal vascular rings cause tracheoesophageal obstruction, resulting in respiratory symptoms and dysphagia in children. Although a large number of children with Rubinstein-Taybi syndrome have frequent respiratory infections and feeding difficulties, there has been no firmly established association between this syndrome and the occurrence of vascular rings. We report on a patient with Rubinstein-Taybi syndrome who had a vascular ring. Since there was a previous report of a similar ring in a child with Rubinstein-Taybi syndrome, we suggest there may be an association between Rubinstein-Taybi syndrome and vascular rings.

Loss of chromosomes 22 and 14 in the malignant progression of meningiomas. A comparative study of fluorescence in situ hybridization (FISH) and standard cytogenetic analysis

The majority of meningiomas are classified as typical and have a relatively benign course. However, approximately 10% are diagnosed as atypical, anaplastic, or malignant and have a worse prognosis. The genetic differences between the typical and higher grade meningiomas are not well characterized, although there appear to be increasingly complex karyotypic changes associated with the higher grade tumors. Because higher grade meningiomas are not common tumors, and because of the inherent problems associated with the culturing of tumors, the use of interphase cytogenetic techniques with paraffin-embedded archival material is desirable for studying these neoplasms. To determine its accuracy in detecting aneuploidy, we performed fluorescence in situ hybridization (FISH) on 2-micron paraffin sections of nine previously karyotyped meningiomas using an alpha-satellite probe for chromosomes 14 and 22. Sections of normal tissue from six patients without malignancy were used as controls. FISH analysis detected all of the chromosome losses in the meningioma cases that had been characterized cytogenetically. In five cases, cell lines not detected by standard cytogenetics were identified by FISH. These results indicate that FISH is a reliable method for detecting chromosomal loss and may be more sensitive than standard cytogenetics alone. Furthermore, the results of this study support the concept that loss of chromosome 14 is associated with malignant progression in meningiomas.

Neuroectodermal (CHIME) syndrome: an additional case with long term follow up of all reported cases

A new neuroectodermal syndrome (designated CHIME syndrome) was described in 1983 with a total of four patients reported, it is presumed to be an autosomal recessive disorder because of recurrence in sibs. The main features include ocular colobomas, congenital heart disease, early onset migratory ichthyosiform dermatosis, mental retardation, conductive hearing loss, seizures, and typical facial features. We report a fifth child with the condition, confirming the unique nature of the condition. Long term follow up information on this patient, as well as the previously described cases, provides information regarding the outcome for these patients, which includes general good health, severe mental retardation, seizures that worsen after puberty, conductive hearing loss, and chronic migratory ichthyosiform skin rash without scarring.

Absent pituitary gland in two brothers with an oral-facial-digital syndrome resembling OFDS II and VI: a new type of OFDS?

The oral-facial-digital syndromes (OFDS) comprise a group of heterogeneous genetic disorders. Considerable clinical overlap exists within the nine described types [Toriello, Clin Dysmorph 2:95-105, 1993], and with other entities such as Pallister-Hall (PH) syndrome and hydrolethalus syndrome, leading to difficulties in the classification of OFDS. We report on two brothers with findings overlapping OFDS II, VI, and Pallister-Hall syndrome who had congenital absence of the pituitary gland. This may represent a new type of OFDS or, alternatively, an example of phenotypic variability within the OFDS. It also emphasizes that agenesis of the pituitary gland can occur in a variety of syndromes with midline defects.

Interphase fluorescence in situ hybridization for trisomy 12 on archival ovarian sex cord-stromal tumors

Trisomy 12 is a nonrandom chromosomal abnormality found in a large proportion of ovarian sex cord-stromal tumors (OSCTs), including thecoma-fibromas (TFs) and granulosa cell tumors (GCTs). The prognostic significance of trisomy 12 in these tumors, however, is unknown. A series of 16 OSCTs, obtained from patients with long-term follow-up, was analyzed for the presence of trisomy 12 by interphase fluorescence in situ hybridization on paraffin-embedded sections. Sections of the contralateral nonneoplastic ovary were available in five cases and utilized as controls. Evidence of trisomy 12 was detected in 9 of 10 TFs, and contrary to previous reports, in only one of six GCTs. One TF with trisomy 12 was a malignant variant that resulted in the death of the patient in 5 months, but the remaining TFs with trisomy 12 were cytologically and clinically benign in those with follow-up available. The single GCT with trisomy 12 was a nonaggressive, stage 1 lesion without evidence of recurrence after 264 months, whereas those GCTs without trisomy 12 included one stage 2 tumor and a cytologically atypical GCT with tumor necrosis and an elevated number of mitotic figures. The evidence suggests that the great majority of OSCTs with trisomy 12 is clinically benign, but not all benign OSCTs have trisomy 12. We conclude that the presence of trisomy 12 is of limited prognostic usefulness in OSCTs.

Malignant rhabdoid tumor of the kidney: involvement of chromosome 22

Cytogenetic and molecular studies have demonstrated that involvement of 22q is a non-random finding in malignant rhabdoid tumors (MRTs) of the brain. We present an MRT of the kidney with the karyotype 47,XY, + i(1)(q10), der(8)t(8;22)(q12;q11.2),der(22)t(8;22)(q23 or q24.1;q11.2). This unbalanced reciprocal translocation was confirmed by fluorescence in situ hybridization (FISH) with chromosome-specific paints for chromosomes 8 and 22. Molecular analysis demonstrated a partial deletion of 22q in the BCR region at q11.2, strengthening the suspicion that this is a critical region for the initiation or progression of these highly malignant neoplasms. Establishing non-random cytogenetic changes in MRTs arising from the kidney may be of value in distinguishing these rare, but often fatal tumors from other renal neoplasms that mimic them histologically. The similarity in cytogenetic and molecular abnormalities between renal and extra-renal MRTs argues against the concept that extra-renal MRTs are only representative of a rhabdoid phenotype, rather than being true rhabdoid tumors.

Choanal atresia in a patient with the deletion (9p) syndrome

We report on a child with choanal atresia and deletion 9p. A review of the literature documented one previous instance of choanal atresia in a patient with del(9p). Choanal atresia may be part of the spectrum of malformations in the deletion (9p) syndrome and its presence should prompt a search for this particular deletion as part of the differential diagnosis.