X-linked congenital ptosis and associated intellectual disability, short stature, microcephaly, cleft palate, digital and genital abnormalities define novel Xq25q26 duplication syndrome.

Submicroscopic duplications along the long arm of the X-chromosome with known phenotypic consequences are relatively rare events. The clinical features resulting from such duplications are various, though they often include intellectual disability, microcephaly, short stature, hypotonia, hypogonadism and feeding difficulties. Female carriers are often phenotypically normal or show a similar but milder phenotype, as in most cases the X-chromosome harbouring the duplication is subject to inactivation. Xq28, which includes MECP2 is the major locus for submicroscopic X-chromosome duplications, whereas duplications in Xq25 and Xq26 have been reported in only a few cases. Using genome-wide array platforms we identified overlapping interstitial Xq25q26 duplications ranging from 0.2 to 4.76 Mb in eight unrelated families with in total five affected males and seven affected females. All affected males shared a common phenotype with intrauterine- and postnatal growth retardation and feeding difficulties in childhood. Three had microcephaly and two out of five suffered from epilepsy. In addition, three males had a distinct facial appearance with congenital bilateral ptosis and large protruding ears and two of them showed a cleft palate. The affected females had various clinical symptoms similar to that of the males with congenital bilateral ptosis in three families as most remarkable feature. Comparison of the gene content of the individual duplications with the respective phenotypes suggested three critical regions with candidate genes (AIFM1, RAB33A, GPC3 and IGSF1) for the common phenotypes, including candidate loci for congenital bilateral ptosis, small head circumference, short stature, genital and digital defects.

Duplication of 7q36.3 encompassing the Sonic Hedgehog (SHH) gene is associated with congenital muscular hypertrophy.

Muscular hypertrophy is a very rare finding on foetal ultrasonography. We present a case with recurrent muscular hypertrophy, liver enlargement and polyhydramnios in two pregnancies. One pregnancy was terminated due to suspicion of a storage disease, whereas the other led to delivery of a boy with muscular hypertrophy and mildly retarded psychomotor development. Array-CGH identified a small duplication of 7q36.3 including the Sonic Hedgehog (SHH) gene in both the aborted foetus and the live born male sib. Neither of the parents carried the 7q36.3 duplication. The consequences of overexpression of SHH in humans are not elucidated, but animal studies have suggested its importance in muscular hypertrophy. We suggest that the clinical findings in the presented case might be explained by the duplication and presumed overexpression of SHH.

Corpus callosum abnormalities, intellectual disability, speech impairment, and autism in patients with haploinsufficiency of ARID1B.

Corpus callosum abnormalities, intellectual disability, speech impairment, and autism in patients with haploinsufficiency of ARID1B. Corpus callosum abnormalities are common brain malformations with a wide clinical spectrum ranging from severe intellectual disability to normal cognitive function. The etiology is expected to be genetic in as much as 30-50% of the cases, but the underlying genetic cause remains unknown in the majority of cases. By next-generation mate-pair sequencing we mapped the chromosomal breakpoints of a patient with a de novo balanced translocation, t(1;6)(p31;q25), agenesis of corpus callosum (CC), intellectual disability, severe speech impairment, and autism. The chromosome 6 breakpoint truncated ARID1B which was also truncated in a recently published translocation patient with a similar phenotype. Quantitative polymerase chain reaction (Q-PCR) data showed that a primer set proximal to the translocation showed increased expression of ARID1B, whereas primer sets spanning or distal to the translocation showed decreased expression in the patient relative to a non-related control set. Phenotype-genotype comparison of the translocation patient to seven unpublished patients with various sized deletions encompassing ARID1B confirms that haploinsufficiency of ARID1B is associated with CC abnormalities, intellectual disability, severe speech impairment, and autism. Our findings emphasize that ARID1B is important in human brain development and function in general, and in the development of CC and in speech development in particular.

Complement factor H deficiency and endocapillary glomerulonephritis due to paternal isodisomy and a novel factor H mutation.

Complement factor H (CFH) is a regulator of the alternative complement activation pathway. Mutations in the CFH gene are associated with atypical hemolytic uremic syndrome, membranoproliferative glomerulonephritis type II and C3 glomerulonephritis. Here, we report a 6-month-old CFH-deficient child presenting with endocapillary glomerulonephritis rather than membranoproliferative glomerulonephritis (MPGN) or C3 glomerulonephritis. Sequence analyses showed homozygosity for a novel CFH missense mutation (Pro139Ser) associated with severely decreased CFH plasma concentration (<6%) but normal mRNA splicing and expression. The father was heterozygous carrier of the mutation, but the mother was a non-carrier. Thus, a large deletion in the maternal CFH locus or uniparental isodisomy was suspected. Polymorphic markers across chromosome 1 showed homozygosity for the paternal allele in all markers and a lack of the maternal allele in six informative markers. This combined with a comparative genomic hybridization assay demonstrated paternal isodisomy. Uniparental isodisomy increases the risk of homozygous variations in other genes on the affected chromosome. Therefore, we analyzed other susceptibility genes on chromosome 1 and found no sequence variation in membrane cofactor protein, but homozygosity for the common deletion of CFH-related proteins 1 and 3, which may contribute to the early onset of disease.

Diagnostic yield by supplementing prenatal metaphase karyotyping with MLPA for microdeletion syndromes and subtelomere imbalances.

OBJECTIVE: The aim of the study was to retrospectively assess the relevance of using multiplex ligation-dependent probe amplification (MLPA) for detection of selected microdeletion syndromes (22q11, Prader-Willi/Angelman, Miller-Dieker, Smith-Magenis, 1p-, Williams), the reciprocal microduplication syndromes and imbalance at the subtelomere regions of chromosomes in a routine prenatal setting. METHOD: A total of 530 prenatal samples were analysed by commercial MLPA kits (SALSA P064, P036 and P069) in addition to rapid aneuploidy testing and G-band karyotyping. RESULTS: Among the prenatal samples with a normal metaphase karyotype, nine submicroscopic imbalances were detected: seven 22q11 deletions (Velocardiofacial/DiGeorge syndrome), one 15q11 deletion (Prader-Willi syndrome) and one terminal deletion of the short arm of chromosome 4 (Wolf-Hirschhorn syndrome). All imbalances were found in amniocentesis (AC) taken due to fetal structural malformation and/or other ultrasound scan (US) detected abnormality. The diagnostic yield was 4.1% in the subgroup with structural malformation and 1.6% in the subgroup with other US abnormality. CONCLUSION: The data set substantiates that additional MLPA analyses for selected microdeletions and subtelomere imbalances are valuable in routine prenatal diagnostics, when a malformation(s) and/or other abnormalities are detected by US. In contrast, the additional MLPA analyses gave no diagnostic yield in case of increased nuchal translucency (NT).

Increased nuchal translucency with normal karyotype: a follow-up study of 100 cases supplemented with CGH and MLPA analyses.

OBJECTIVE: To evaluate whether high-resolution comparative genomic hybridization (HR-CGH) and subtelomeric and syndrome-specific multiplex ligation-dependent probe amplification (MLPA) would detect minor chromosomal aberrations in fetuses with increased nuchal translucency thickness (NT) and normal karyotype on conventional karyotyping. METHODS: Chorionic villus samples from 100 fetuses with NT > or = 99(th) percentile and normal G-banding analysis and MLPA for detection of aneuploidies for chromosomes 13, 18, 21, X and Y were included. Examinations were supplemented by HR-CGH and MLPA for syndromes and subtelomeric regions. Pregnancy outcome was followed up. RESULTS: Among 80 liveborn children who were followed up, three (4%) had syndromes involving mental retardation, including a case of Sotos syndrome caused by a de novo mutation. 15% of fetuses were lost during pregnancy due to abnormalities and termination. The rate of adverse outcome overall was 18%. HR-CGH and MLPA did not detect any chromosomal aberrations associated with the syndromes. CONCLUSION: The rate of adverse outcome was similar to levels recorded in the literature. Using CGH and MLPA did not increase the detection rate of genetic disease, which supports the current approach of repeated ultrasound examinations in these high-risk pregnancies.

A new microduplication syndrome encompassing the region of the Miller-Dieker (17p13 deletion) syndrome.

BACKGROUND: The use of array comparative genome hybridisation (CGH) analyses for investigation of children with mental retardation has led to the identification of a growing number of new microdeletion and microduplication syndromes, some of which have become clinically well characterised and some that await further delineation. This report describes three children with de novo 17p13.1 duplications encompassing the PAFAH1B1 gene, who had similar phenotypic features, including mild to moderate developmental delay, hypotonia and facial dysmorphism, and compares them to the few previously reported cases with this duplication. METHODS: Multiplex ligation-dependent probe amplification (MLPA) or array-CGH was used to diagnose three developmentally delayed children with duplications of 17p13. The duplications were characterised further using Agilent array technology, revealing duplication sizes from 1.8 to 4.0 Mb, with a region of overlap corresponding to 1.8 Mb. Detailed clinical information was obtained from patient files and personal examinations. RESULTS: The developmental delay and similar clinical features in the three patients were most likely due to a common microduplication of 17p13. CONCLUSIONS: In contrast to patients with deletion of the region (Miller-Dieker syndrome) the patients reported here had mild to moderate retardation and displayed no lissencephaly or gross brain malformations. Further cases with similar duplications are expected to be diagnosed, and will contribute to the delineation of a potential new microduplication syndrome of 17p13.

Chromosomal deletion unmasking a recessive disease: 22q13 deletion syndrome and metachromatic leukodystrophy.

A deletion on one chromosome and a mutant allele on the other may cause an autosomal recessive disease. We report on two patients with mental retardation, dysmorphic features and low catalytic activity of arylsulfatase A. One patient had a pathogenic mutation in the arylsulfatase A gene (ARSA) and succumbed to metachromatic leukodystrophy (MLD). The other patient had a pseudoallele, which does not lead to MLD. The presenting clinical features and low arylsulfatase A activity were explained, in each patients, by a deletion of 22q13 and, thereby, of one allele of ARSA.

Impact of low copy repeats on the generation of balanced and unbalanced chromosomal aberrations in mental retardation.

Low copy repeats (LCRs) are stretches of duplicated DNA that are more than 1 kb in size and share a sequence similarity that exceeds 90%. Non-allelic homologous recombination (NAHR) between highly similar LCRs has been implicated in numerous genomic disorders. This study aimed at defining the impact of LCRs on the generation of balanced and unbalanced chromosomal rearrangements in mentally retarded patients. A cohort of 22 patients, preselected for the presence of submicroscopic imbalances, was analysed using submegabase resolution tiling path array CGH and the results were compared with a set of 41 patients with balanced translocations and breakpoints that were mapped to the BAC level by FISH. Our data indicate an accumulation of LCRs at breakpoints of both balanced and unbalanced rearrangements. LCRs with high sequence similarity in both breakpoint regions, suggesting NAHR as the most likely cause of rearrangement, were observed in 6/22 patients with chromosomal imbalances, but not in any of the balanced translocation cases studied. In case of chromosomal imbalances, the likelihood of NAHR seems to be inversely related to the size of the aberration. Our data also suggest the presence of additional mechanisms coinciding with or dependent on the presence of LCRs that may induce an increased instability at these chromosomal sites.

Further delineation of the 22q13 deletion syndrome.

A chromosomal deletion syndrome associated with a 22q13 microdeletion has previously been reported in approximately 75 children. We report six cases from Denmark with a deletion of 22q13. One was cytogenetically visible by conventional karyotyping, one was diagnosed by high resolution karyotyping after the demonstration of low arylsulfatase A activity. Two were diagnosed by high resolution CGH analysis, one was diagnosed by multisubtelomeric FISH analysis and one was diagnosed serendipitously as lack of the control signal in a FISH analysis for 22q11 deletion. One of the cases was a mosaic with 16% of cells showing two signals. The phenotype of the children included: generalized developmental delay, compromised language development, hypotonia, normal or accelerated growth and minor facial dysmorphism. Other features were partial agenesis of the corpus callosum, bilateral ureteropelvic stricture, gastroesophageal reflux and hearing loss. One case had a different phenotype, and showed a deletion as well as a duplication. The extent of the deletion was studied by quantitative PCR analysis of a number of DNA markers in the 22q13 region. The deletions varied in size, extending from 4.0 to 9.0 Mb. The clinical phenotype seemed rather similar although some specific features might be attributable to differences in deletions.

Engineering high-temperature stable nanocomposite materials.

The low thermal stability of nanoparticles typically restricts their use in catalytic and other applications to low- to moderate-temperature conditions. We present a novel approach to the stabilization of nanosized noble metal particles by embedding them in a high-temperature stabilized hexa-aluminate matrix. The simple 'one-pot' approach is based on a microemulsion-templated sol-gel synthesis and yields mesoporous nanocomposite materials with pure textural porosity and excellent high-temperature stability up to about 1200 °C. To our knowledge, this is the first time that metal nanoparticles have been stabilized to such high temperatures. We furthermore find that the microemulsion templating allows a tailoring of the ceramic matrix without influencing the size of the embedded Pt particle. This opens up the possibility of a true multiscale engineering of nanocomposite materials. We see these novel materials therefore not only as very promising candidates for a broad range of high-temperature catalytic applications, but generally view this versatile synthesis route as a first step towards expanding the parameter range for nanoparticle applications.

The most common chromosome aberration detected by high-resolution comparative genomic hybridization in vulvar intraepithelial neoplasia is not seen in vulvar squamous cell carcinoma.

We analyzed genetic changes in condylomas (four cases), vulvar intraepithelial neoplasia I-III (VIN I-III, eleven cases), and primary vulvar squamous cell carcinomas (VSCC, ten cases) by high-resolution comparative genomic hybridization (HR-CGH) and flowcytometry. All samples were also human papilloma virus (HPV)-genotyped. Gain of chromosome 1, the aberration most often seen in VIN III (67%), was not seen in HPV-positive or -negative VSCCs (0%). Both VIN III and VSCC frequently showed gain of 3q (56 and 70%, respectively). The VIN III samples often demonstrated gain of 20q (56%) and 20p (44%), and the VSCC samples gain of 8q (60%), loss of 3p (50%), and 8p (40%). None of the four most frequent changes in the VSCC samples occurred exclusively in the HPV-positive or -negative samples. As expected, we did not find any cytogenetic changes in condylomas and nearly any changes in VIN I-II.

De novo complex chromosomal rearrangements (CCR) involving chromosome 1, 5, and 6 resulting in microdeletion for 6q14 in a female carrier with psychotic disorder.

A 23-year-old obese woman with a psychotic disorder was found to have a de novo apparently balanced complex chromosomal rearrangement involving chromosomes 1, 5, and 6. Molecular cytogenetic analyses using high-resolution comparative genomic hybridization (HR-CGH) showed a microdeletion at 6q14 in a der(6). Application of HR-CGH facilitated detection of micro-rearrangement of all de novo apparently balanced complex chromosomal rearrangements (CCR) and supported the localization of the breakpoint. According to our knowledge, no constitutional interstitial microdeletion of chromosome 6q14 has been found associated with a schizoid-type phenotype.

High resolution comparative genomic hybridisation in clinical cytogenetics.

High resolution comparative genomic hybridisation (HR-CGH) is a diagnostic tool in our clinical cytogenetics laboratory. The present survey reports the results of 253 clinical cases in which 47 abnormalities were detected. Among 144 dysmorphic and mentally retarded subjects with a normal conventional karyotype, 15 (10%) had small deletions or duplications, of which 11 were interstitial. In addition, a case of mosaic trisomy 9 was detected. Among 25 dysmorphic and mentally retarded subjects carrying apparently balanced de novo translocations, four had deletions at translocation breakpoints and two had deletions elsewhere in the genome. Seventeen of 19 complex rearrangements were clarified by HR-CGH. A small supernumerary marker chromosome occurring with low frequency and the breakpoint of a mosaic r(18) case could not be clarified. Three of 19 other abnormalities could not be confirmed by HR-CGH. One was a Williams syndrome deletion and two were DiGeorge syndrome deletions, which were apparently below the resolution of HR-CGH. However, we were able to confirm Angelman and Prader-Willi syndrome deletions, which are about 3-5 Mb. We conclude that HR-CGH should be used for the evaluation of (1) dysmorphic and mentally retarded subjects where normal karyotyping has failed to show abnormalities, (2) dysmorphic and mentally retarded subjects carrying apparently balanced de novo translocations, (3) apparently balanced de novo translocations detected prenatally, and (4) for clarification of complex structural rearrangements.

[Detection of submicroscopic chromosome abnormalities by comparative genomic hybridization]. / Påvisning af submikroskopiske kromosomfejl med komparativ genomisk hybridisering.

INTRODUCTION: The purpose was to detect chromosome abnormalities in dysmorphic and mentally retarded individuals with normal karyotypes by means of comparative genomic hybridisation (CGH). MATERIAL AND METHODS: One hundred and forty-four individuals with normal karyotype underwent CGH analysis with a new detection technique where fixed limits are replaced by dynamic standard reference intervals. This method provides improved resolution and thereby detects minor chromosome abnormalities. RESULTS: Fifteen minor abnormalities (10%) and one trisomy 9 mosaic were found. Eleven were interstitial deletions or duplications, which cannot be detected by screening with other cytogenetic techniques. Three were terminal deletions or duplications and one was a terminal unbalanced translocation. DISCUSSION: CGH analysis with dynamic standard reference intervals is a new objective and quantitative method, which is suitable for screening for small chromosome abnormalities that can not be detected by conventional chromosome analysis. The method is recommended for use in the investigation of dysmorphic and mentally retarded individuals, in whom abnormalities are not found by ordinary karyotyping.

Comparative genomic hybridization reveals non-random chromosomal aberrations in early preinvasive cervical lesions.

We performed CGH analysis on 34 cervical lesions, which included 8 cases of koilocytosis, 6 mild dysplasias and 20 moderate dysplasias. Chromosome aberrations were detected in 11 cases of which 9 were moderate dysplasias. A total of 55 chromosome arms were involved. The most frequent aberrations were losses of 5p and Xq, each of which was present in 5/34 cases. Gain of 3q was detected in two moderate dysplasias. This aberration is the most frequent copy number change in advanced-stage cervical carcinoma. A considerable number of the aberrations found in the preinvasive cases of this study are frequently present in invasive cervical tumors. The presence of apparently non-random chromosome aberrations in early preinvasive cervical lesions has not previously been described.

Activation of Raf-1 is defective in annexin 6 overexpressing Chinese hamster ovary cells.

Annexin 6 is a Ca2+-dependent phospholipid-binding protein involved in membrane trafficking. In this study we demonstrate the association of Raf-1 with recombinant rat annexin 6. Raf-annexin 6 interaction was shown to be independent of cell activation by epidermal growth factor (EGF) or phorbol esters (12-O-tetradecanoyl-phorbol-13-acetate (TPA)). A stable Chinese hamster ovary (CHO)-anx6 cell line overexpressing annexin 6 was established to examine the function of annexin 6. In these cells, no increase of Ras-GTP levels, induced by EGF or TPA, was detected. In addition, the activity of Raf was completely inhibited, whereas the mitogen-activated protein kinase-P was unaffected.

[Can ingestion of cranberry juice reduce the incidence of urinary tract infections in a department of geriatric medicine?]. / Reducerer brug af tranebaersaft hyppigheden af urinvejsinfektioner i en geriatrisk afdeling?

INTRODUCTION: The incidence of urinary tract infections was compared in two geriatric units, where patients were offered cranberry juice and the usual mixed berry juice, respectively. METHODS: In all cases where urinary tract infection was suspected, the doctors noted symptoms and signs used as indication for urinary culture. The urine collected from men was the usual mid-flow specimen, whereas the specimens from women were taken from a bedpan and by catheter. End points were the prevalence of symptoms leading to urine culture, specimens with significant growth of bacteria, and the use of antibiotics. RESULTS: Urine specimens were cultured in 140/338 cases. The reason for culture in 23% was general symptoms and in 62% urinary tract symptoms. A significant growth of bacteria was found in 54% and this information led to antibiotic treatment in 44%. In all cases (n = 55) where bedpan and catheter specimens were taken, the results were identical. CONCLUSION: Cranberry juice in a geriatric department, where the mean stay was 4 weeks, did not influence the incidence of urinary tract infections.

Duplication or amplification of chromosome band 11q23, including the unrearranged MLL gene, is a recurrent abnormality in therapy-related MDS and AML, and is closely related to mutation of the TP53 gene and to previous therapy with alkylating agents.

Gene amplification is a rare phenomenon in acute leukemia, but recently amplification of specific chromosome bands containing genes rearranged in leukemia-specific balanced chromosome translocations has been reported in a few cases. We detected duplication or amplification of chromosome band 11q23 with 3-7 copies of the MLL gene by fluorescence in situ hybridization in 12 out of 70 unselected patients with therapy-related myelodysplasia or acute myeloid leukemia (17%). In all but one case, the supernumerary copies of MLL were located to previously unidentified marker chromosomes or unbalanced translocations. In 4 of the 12 patients, 2-6 copies were located together on the same chromosome arm representing amplification, 7 patients had single, extra duplicated copies of MLL, whereas both amplification and duplication were observed in the same cell in 1 patient. Comparative genomic hybridization demonstrated gain of varying, often large parts of 11q in five patients. The MLL gene was shown to be unrearranged in all 12 patients. Seven out of eight patients with duplication or amplification of MLL had mutations of TP53. Patients with supernumerary copies of MLL were in general older (P = 0.007) and had a shorter survival (P < 0.001) compared to other patients. Duplication or amplification of MLL was significantly associated with a complex karyotype (P = 0.002), with deletion or loss of 5q (P = 0.001), and with prior therapy with alkylating agents. These results support the existence of a specific genetic pathway in t-MDS and t-AML with many previously unidentified chromosome aberrations demonstrated to represent extra copies of parts of 11q, including the unrearranged MLL gene.