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Lateral ray polydactyly: a case of duplicated metatarsal with normal phalanges.

Lateral ray polydactyly of the foot is morphologically classified on the basis of the external appearance and the anatomic patterns of bony structures. Classification is difficult when the level of duplication is not apparent. We encountered a case of a duplicated metatarsal with no duplication of phalanges. The anomaly was considered to be a case of polydactyly because there were supernumerous metatarsals. On the basis of embryological failure, limb malformations are classified into several categories, and polydactyly belongs to that of duplication. There are, however, some malformations that are difficult to classify clearly. We considered our case to be a result of duplication followed by fusion of the digits.

Child, Preschool↗

Ileal duplication cyst causing massive bleeding in a child.

Intestinal duplication is a rare congenital anomaly; nonetheless, it comprises more than half of all alimentary duplication disorders. Our case report describes the hemorrhagic sequelae of this entity with surgical and pathologic findings. A review of anatomical classification, embryology, and natural history of duplication cyst follows; differentiating characteristics of duplication cyst versus Meckel's diverticulum are outlined. Intestinal duplication cyst should be considered in the differential diagnosis of GI bleeding, especially in children.

Child↗

Partial duplication of the face: case report and review.

Complete or partial facial duplication is a rare congenital malformation. A spectrum of structural abnormalities varying in degrees of severity has been described in affected individuals. We present discordance for facial duplication between monozygotic twins in which maxillary and mandibular duplication was present in one. The involved twin showed the following findings: ocular hypertelorism, bifidity of the nose, duplication of the maxilla, macrostomia, cleft of the lower lip, hamartoma of the vomer, supernumerary teeth, duplication of the mandibular teeth, bifidity of the tongue, and hamartoma of the floor of the mouth. Surgical management of the facial anomalies is discussed. A review of the literature and discussion of this rare malformation are presented.

Cleft Palate↗

Lumbar spine duplication presenting as adolescent scoliosis. A case report.

STUDY DESIGN: A report of a case of lumbar spine duplication with the clinical appearance of adolescent scoliosis. OBJECTIVE: To increase knowledge about the pathogenesis and treatment of lumbar spinal duplication. SUMMARY OF BACKGROUND DATA: Although there have been other reports of lumbar spine duplication of this magnitude, these malformations typically are associated with severe neurologic abnormalities (dicephalus, myelomeningocele) or gastrointestinal abnormalities (omphalocele, neurenteric fistulas). Several investigators have recommended early surgical intervention for this abnormality because of the perceived risk of progressive neurologic abnormality from tethering of the cord. METHODS: In a 13-year-old girl who had truncal asymmetry, lumbar spine duplication was noted on plain radiographs. A magnetic resonance study was obtained, and the patient was observed with conservative treatment for 3 years. RESULTS: Although extensive abnormalities were noted on the magnetic resonance images, which were related to duplication of spinal cord and vertebral bodies, the patient was neurologically intact and remained so until skeletal maturity. CONCLUSIONS: This rare malformation typically has severe neurologic sequelae. Conservative management in the reported patient did not result in a progressive neurologic lesion at the time of skeletal maturity.

Adolescent↗

On the structure, genesis and significance of DNA duplications at the Rous sarcoma proviral insertion sites in Rat-1 cells.

We have previously shown that most Rous sarcoma proviruses in Rat-1 cells are simple insertions, at apparently random sites, and are not transcribed. A small minority of simple insertions are transcribed and these show a bias to insertion at sites closely 3' to presumptive cellular CG-rich islands. However, most transcribed proviruses are complex, typified by contiguous duplications of proviral DNA 5' to a complete proviral unit. The cellular sites of these complex insertions are unknown and their structure and significance incompletely documented. We report here more extensive analyses of proviral duplications, with the following findings. The 5' duplications predominantly involve proviral regions known to contain enhancer functions, substantiating earlier data. The cellular insertion sites are not biased to CG-rich loci at the level displayed by simple transcribed proviruses. The detailed structure of two duplications, and partial analysis of several others, strongly favours their genesis by illegitimate template transfer at reverse transcription, followed by self-recombination. These findings show that aberrant reverse transcription can generate duplications that dispense with the need for an expressed provirus to be integrated at a favourable cellular site.

Animals↗

Landmarks in the early duplication cycles of Aspergillus fumigatus and Aspergillus nidulans: polarity, germ tube emergence and septation.

When the spores of filamentous fungi break dormancy, nuclear division is accompanied by a series of ordered morphological events including the switch from isotropic to polar growth, the emergence of a second germ tube from the conidium and septation. Correlation of these morphological events with nuclear number allows them to serve as duplication cycle landmarks. Early duplication cycle landmarks have been characterized in Aspergillus nidulans, but not in other filamentous fungi. To learn more about duplication cycle control in filamentous fungi, a study was undertaken to compare the timing of landmarks in Aspergillus fumigatus and A. nidulans. Nuclear duplication took approximately 45 min in A. fumigatus, with mitosis occupying roughly 5% of this period. Under the same conditions, nuclear duplication in A. nidulans took approximately 60 min, with mitosis occupying roughly 4% of this period. In A. fumigatus the isotropic to polar switch preceded the first mitosis in 22% of cells, while in A. nidulans the isotropic to polar switch did not occur until after the first mitosis. In both A. fumigatus and A. nidulans the earliest emergence of a second germ tube from the conidium occurred after the third mitotic division. However, by the fifth mitosis only 19% of A. fumigatus conidia had a second germ tube, compared to 98% of A. nidulans conidia. In both A. fumigatus and A. nidulans, formation of the first septum occurred after the fourth mitotic division. In all experiments a few cells lagged behind the others in nuclear number. In this delayed group, it was common to see landmark events at an earlier mitotic division. Differences in nuclear number when identical landmarks occur in A. fumigatus versus A. nidulans, and uncoupling of mitotic division and landmarks in delayed cells suggest that nuclear division and morphogenesis lie in parallel pathways, perhaps coordinated by checkpoints.

Aspergillus fumigatus↗

Segmental duplications containing tandem repeated genes encoding putative deubiquitinating enzymes.

Both inter- and intra-chromosomal segmental duplications are known occurred in human genome during evolution. Few cases of such segments involving functional genes have been reported. While searching for the human orthologs of murine hematopoietic deubiquitinating enzymes (DUBs), we identified four clusters of DUB-like genes on chromosome 4p15 and chromosome 8p22-23 that are over 90% identical to each other at the DNA level. These genes are expressed in a cell type- and activation-specific manner, with different clusters possessing potentially distinct expression profiles. Examining the surrounding sequences of these gene duplication events, we have identified previously unreported conserved sequence elements that are as large as 35 to 74 kb encircling the gene clusters. Traces of these elements are also found on chromosome 12p13 and chromosome 11q13. The coding and immediate upstream sequences for DUB-like genes as well as the surrounding conserved elements, are present in the chimpanzee trace database, but not in rodent genome. We hypothesize that the segments containing these DUB clusters and surrounding elements arose relatively recently in evolution through inter- and intra-chromosomal duplicative transpositions, following the divergence of primates and rodents. Genome wide systematical search of the segmental duplication containing duplicated gene cluster has been performed.

Animals↗

Interchromosomal duplication for the short arm of chromosome no. 9: report of three cases due to a familial translocation t(9; 11) and one case with a de novo 47, XX, +9p karyotype.

Four cases of the 9p duplication syndrome are described. Three affected sibs resulted from a maternal t(9;11) translocation and have a duplication of the segment 9p13 leads to 9pter. They have the typical facies, hands and other features of the syndrome but are relatively mildly retarded. The fourth case has a de novo duplication of the short arm of chromosome 9. Her features are also typical although she is more retarded, particularly in expressive speech, than the other three individuals and had club feet. These observations further confirm the distinctive clinical features of this type of duplication, and support previous suggestions that the severity is roughly correlated with the length of the duplicated segment.

Adolescent↗

An intragenic tandem duplication in a transcriptional regulatory gene for anthocyanin biosynthesis confers pale-colored flowers and seeds with fine spots in Ipomoea tricolor.

While the wild-type morning glory (Ipomoea tricolor) displays bright-blue flowers and dark-brown seeds, its spontaneous mutant, Blue Star, carrying the mutable ivory seed-variegated (ivs-v) allele, exhibits pale-blue flowers with a few fine blue spots and ivory seeds with tiny dark-brown spots. The mutable allele is caused by an intragenic tandem duplication of 3.3 kbp within a gene for transcriptional activator containing a basic helix-loop-helix (bHLH) DNA-binding motif. Each of the tandem repeats is flanked by a 3-bp sequence AAT, indicating that the 3-bp microhomology is used to generate the tandem duplication. The transcripts in the pale-blue flower buds of the mutant contain an internal 583-bp tandem duplication that results in the production of a truncated polypeptide lacking the bHLH domain. The mRNA accumulation of most of the structural genes encoding enzymes for anthocyanin biosynthesis in the flower buds of the mutant was significantly reduced. The transcripts identical to the wild-type mRNAs for the transcriptional activator were present abundantly in blue spots of the variegated flowers, whereas the transcripts containing the 583-bp tandem duplication were predominant in the pale-blue background of the same flowers. The flower and seed variegations studied here are likely to be caused by somatic homologous recombination between an intragenic tandem duplication in the gene encoding a bHLH transcriptional activator for anthocyanin biosynthesis, whereas various flower variegations are reported to be caused by excision of DNA transposons inserted into pigmentation genes.

Anthocyanins↗

Deletions, duplications and novel restriction fragment length polymorphism in Duchenne and Becker muscular dystrophies.

To determine the mutations of Southern Chinese with Duchenne and Becker muscular dystrophies (DMD, BMD), we analysed 28 DMD and BMD patients in 24 unrelated families for intragenic deletions and duplications by using cDNA probes covering the entire 14 kb of the dystrophin gene. Deletions were detected in nine unrelated patients (seven patients by probe 8 and two by probe 2b-3). Gene duplications were detected by probe 1-2a in two patients with the duplication bands confirmed in both Hind III and Bgl II digests and by densitometry. A third patient was found to have a junction fragment with Bgl II and a duplication band with Hind III by probe 5b-7. Therefore 50% of the 24 unrelated families were found to have either deletions or duplications. A previously undescribed restriction fragment length polymorphism (RFLP) was found in one family with probe 5b-7 in Bgl II digests which was found to segregate with the disease phenotype. This new RFLP was not detected in over 70 unrelated X chromosomes we have examined so far, and appeared to be "private" for this family. The presence of this new restriction site may or may not be the mutation responsible for the disease phenotype.

Asian People↗

Charcot-Marie-Tooth disease type 1A: the parental origin of a de novo 17p11.2-p12 duplication.

Charcot-Marie-Tooth disease type 1A (CMT1A) is an autosomal dominant peripheral neuropathy associated with a DNA duplication on chromosome 17p11.2-p12 in the majority of cases. Most of the sporadic cases are due to a de novo duplication. We have screened for this duplication in 11 Danish patients with CMT type 1, using four different techniques, and identified a de novo duplication in a sporadic case. Analysis of the fully informative pVAW409R3a alleles in this family showed the duplication to be of paternal origin.

Adult↗

Ileal duplication cyst associated with heterotopic pancreas: report of a case and literature review.

A rare case of solitary ileal duplication cyst accompanied by heterotopic pancreas in the terminal ileum is presented. An 8 year old boy with an ovoid shaped, elastic soft and pendant-growing ileal duplication cyst associated with aberrant pancreatic tissue but not communicating with the lumen of the ileum, underwent an adhesiotomy for a small intestinal adhesion that caused bowel obstruction. The obstructive state of the intestine seemed to be caused by an inflammation of the duplication cyst which was 4.5 x 2.7 x 2.5 cm and oval in shape. Excision of the cyst and the heterotopic pancreas was curative. The histological findings were identical to heterotopic pancreas accompanied by ileal duplication without any clinical features of heterotopic pancreas. A review of the literature is presented along with the author's experience in a case of ileal duplication cyst associated with heterotopic pancreas located in the ileum.

Child↗

Duplication of the cervical oesophagus in adults.

An adult male patient with duplication cyst of the cervical oesophagus is reported. Benign tumours of the oesophagus are rare and amongst them the congenital cysts form a small group. Only four cases of duplication of the cervical oesophagus have been reported in the literature, all initially presenting in children. Patients usually present with pressure symptoms due to rapid enlargement of the cyst secondary to bleeding or infection. Diagnosis previously has been suggested by barium swallow and oesophagoscopy. Computed tomography (CT) clearly demonstrated the oesophageal duplication. This report describes the first patient to present with a cervical duplication of the oesophagus in adulthood and only the second in whom CT has been used to establish the diagnosis. Surgical excision is recommended in all patients with duplication cysts of the cervical oesophagus.

Adult↗

Lower pole pelvi-ureteric junction obstruction in duplicated collecting systems.

OBJECTIVE: To determine the incidence and efficacy of treatment for pelvi-ureteric junction obstruction (PUJO, the most common cause of hydronephrosis in the fetal kidney) in duplicated systems. PATIENTS AND METHODS: We retrospectively assessed patients with PUJO in a duplex collecting system, reviewing each case for age, sex, anatomy, presenting symptoms and type of management. RESULTS: From 1994 to 2004, 1413 patients were identified to have hydronephrosis; 243 of them had pyeloplasty for PUJO, and five (2%) involved the lower pole of a duplicated collecting system. In two of the patients the presentation was prenatal hydronephrosis (mean age at diagnosis 6 weeks) and the remainder presented with flank pain and pyelonephritis (mean age 5 years); all were boys. There was only one incomplete duplication (Y type). Four patients had a dismembered pyeloplasty and one a ureteric calycostomy. Vesico-ureteric reflux was present in three patients and two required common sheath reimplantation. On a radioisotope scan during the follow-up (mean 12 months) the five patients showed an improvement and no evidence of functional obstruction. CONCLUSION: The incidence of PUJO in duplicated systems was 2%; treatment should be individualized and requires a careful preoperative evaluation. This anomaly appears to be more common in boys and in completely duplicated systems.

Child↗

Y-type urethral duplication in the male.

OBJECTIVE: To present a single series of Y-type duplication with an analysis of the presenting features, the management and outcome, as complete Y-type urethral duplication in the male is a rare congenital anomaly that presents many challenges. PATIENTS AND METHODS: We retrospectively reviewed patient charts, identifying those with urethral duplication, and then those with complete Y-type duplication. The age at presentation, investigations, management and outcomes were reviewed. RESULTS: Of 49 patients with a diagnosis of urethral duplication, 13 had the complete Y-type. Three were lost to follow-up and were therefore excluded from the study. The median (range) age at presentation was 2 months (birth to 10 years). All patients had other comorbidities, with anorectal malformations in seven, renal agenesis in four, sacral agenesis/partial agenesis in two, and unilateral/bilateral cryptorchidism in four. Presenting features included passage of urine perineally or rectally in seven, and dribbling from the orthotopic urethral meatus in one. The diagnosis was confirmed by micturating cysto-urethrography. A mean of 14 procedures was required to achieve a final complete repair, and included urethral reconstruction, repair of fistulae, urethral dilatation, and evaluative cystoscopy. Excluding cystoscopy and urethral dilatation, a mean (range) of 3 (1-5) reconstructive procedures was required in each patient. The median follow-up was 8 years. Five boys developed urethral strictures and one developed multiple fistulae. The best outcomes were in boys who had a staged urethral reconstruction. CONCLUSION: Due to the strong association with other congenital anomalies we recommend that all patients should be evaluated thoroughly, including a detailed physical examination, renal tract ultrasonography and spinal radiography. Surgical management remains a significant challenge, requiring many procedures with unpredictable outcomes, the goals of which should be to maintain continence and reconstruct the urethra with good cosmesis. The optimum management scheme must be individualized in this rare condition.

Abnormalities, Multiple↗

New insights into the genomic organization and origin of the major histocompatibility complex: role of chromosomal (genome) duplication in the emergence of the adaptive immune system.

Recently, it became clear that the human and mouse genomes contain at least three regions paralogous to the major histocompatibility complex (MHC) region. This observation led us to the proposal that the MHC region emerged as a result of chromosomal duplication that took place at an early stage of vertebrate evolution. Here I briefly review this proposal. Accumulating evidence indicates that (a) genome-wide duplication(s) took place close to the origins of vertebrates. Taking this and others into account, I suggest that the duplication(s) involving the MHC region probably took place as a part of the genome-wide duplication(s). The human T cell receptor (TCR) and immunoglobulin (Ig) genes also appear to be located on paralogous chromosomal segments. These findings raise the possibility that the genome-wide duplication provided a major impetus not only to the emergence of the full-fledged MHC system, but also to the appearance of other key molecules of the adaptive immune system such as TCR and Ig.

Animals↗

IS1630 of Mycoplasma fermentans, a novel IS30-type insertion element that targets and duplicates inverted repeats of variable length and sequence during insertion.

A new insertion sequence (IS) of Mycoplasma fermentans is described. This element, designated IS1630, is 1,377 bp long and has 27-bp inverted repeats at the termini. A single open reading frame (ORF), predicted to encode a basic protein of either 366 or 387 amino acids (depending on the start codon utilized), occupies most of this compact element. The predicted translation product of this ORF has homology to transposases of the IS30 family of IS elements and is most closely related (27% identical amino acid residues) to the product of the prototype of the group, IS30. Multiple copies of IS1630 are present in the genomes of at least two M. fermentans strains. Characterization and comparison of nine copies of the element revealed that IS1630 exhibits unusual target site specificity and, upon insertion, duplicates target sequences in a manner unlike that of any other IS element. IS1630 was shown to have the striking ability to target and duplicate inverted repeats of variable length and sequence during transposition. IS30-type elements typically generate 2- or 3-bp target site duplications, whereas those created by IS1630 vary between 19 and 26 bp. With the exception of two recently reported IS4-type elements which have the ability to generate variable large duplications (B. B. Plikaytis, J. T. Crawford, and T. M. Shinnick, J. Bacteriol. 180:1037-1043, 1998; E. M. Vilei, J. Nicolet, and J. Frey, J. Bacteriol. 181:1319-1323, 1999), such large direct repeats had not been observed for other IS elements. Interestingly, the IS1630-generated duplications are all symmetrical inverted repeat sequences that are apparently derived from rho-independent transcription terminators of neighboring genes. Although the consensus target site for IS30 is almost palindromic, individual target sites possess considerably less inverted symmetry. In contrast, IS1630 appears to exhibit an increased stringency for inverted repeat recognition, since the majority of target sites had no mismatches in the inverted repeat sequences. In the course of this study, an additional copy of the previously identified insertion sequence ISMi1 was cloned. Analysis of the sequence of this element revealed that the transposase encoded by this element is more than 200 amino acid residues longer and is more closely related to the products of other IS3 family members than had previously been recognized. A potential site for programmed translational frameshifting in ISMi1 was also identified.

Amino Acid Sequence↗

Bacillus subtilis SMC is required for proper arrangement of the chromosome and for efficient segregation of replication termini but not for bipolar movement of newly duplicated origin regions.

SMC protein is required for chromosome condensation and for the faithful segregation of daughter chromosomes in Bacillus subtilis. The visualization of specific sites on the chromosome showed that newly duplicated origin regions in growing cells of an smc mutant were able to segregate from each other but that the location of origin regions was frequently aberrant. In contrast, the segregation of replication termini was impaired in smc mutant cells. This analysis was extended to germinating spores of an smc mutant. The results showed that during germination, newly duplicated origins, but not termini, were able to separate from each other in the absence of SMC. Also, DAPI (4',6'-diamidino-2-phenylindole) staining revealed that chromosomes in germinating spores were able to undergo partial or complete replication but that the daughter chromosomes were blocked at a late stage in the segregation process. These findings were confirmed by time-lapse microscopy, which showed that after duplication in growing cells the origin regions underwent rapid movement toward opposite poles of the cell in the absence of SMC. This indicates that SMC is not a required component of the mitotic motor that initially drives origins apart after their duplication. It is also concluded that SMC is needed to maintain the proper layout of the chromosome in the cell and that it functions in the cell cycle after origin separation but prior to complete segregation or replication of daughter chromosomes. It is proposed here that chromosome segregation takes place in at least two steps: an SMC-independent step in which origins move apart and a subsequent SMC-dependent step in which newly duplicated chromosomes condense and are thereby drawn apart.

Bacillus subtilis↗