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PubMed1975

Duplication of the haemoglobin alpha-gene.

Gene duplication is one of the basic processes underlying evolutionary changes. The gamma-chains of human foetal haemoglobin is coded by multiple structural genes. The delta-chains of Hb A2 can be regarded as a duplication of the beta-locus. We have presented the first evidence for the presence of two major alpha-chain loci in man. The alpha-gene appears to have duplicated recently, since apart of the single point mutations characterizing Hb J-Buda and Hb G-Pest, the two alpha-gene products seem to be identical. Sensitive immunochemical measurement techniques may reveal structural differences which might escape detection by chemical methods based on differences in charge and/or chromatographic behaviour. Anti-alpha-chain sera recognizing the single amino acid substitution in alphaJ-Buda could be raised in rabbits. The anti-alpha-chain sera were found to be more powerful tools for detecting differences in the primary structure of the chain than the immune sera raised against the whole tetramer. None of the immune sera could reliably differentiate Hb G-Pest from Hb A1. The relative strength of complement fixation of the alpha-chains from haemoglobin A1 F and A2 was compared by hybridizing these human haemoglobins with caninehaemoglobin and measuring the quantitative complement fixation of the different hybrids with anti-Hb A1 and anti-alphaA1 rabbit immune sera. No antigenic difference among the alpha-chains from haemoglobins A1, A2 and F could be detected by this method either with anti-A1 or with anti-alphaA1 sera. These results do not exclude the possibility of conformational differences between the alpha-chains in native Hb A and Hb F. The antigenic activity of the alpha-chains of Hb A from normal subjects (alphaA1) and of the alpha-chains of Hb A from a double heterozygote for alphaJ-Buda and alphaG-Pest (alphaA1) were compared by the complement fixation technique. Definite differences could be detected in the relative strength of complement fixation by alphaA1 and alphaA1 with anti-alphaA1 serum. Final decision as to whether alpha-chain duplication is a universal phenomenon or whether it is restricted to only a part of mankind cannot be drawn until the presence of a silent alpha-thalassaemia gene is not excluded in some debated cases by reliable chemical methods. Measurement of alpha-globin genes in Hb H disease with cDNA enriched in alpha-globin sequences provided direct evidence that a non-thalassaemic subject has to have at least four alpha-globin genes per diploid cell.

Chromosome Mapping↗
PubMed1981

Ocular abnormality associated with partial duplication of chromosome 13.

We studied a one-year-old child with multiple malformations and a tandem duplication of the distal two-thirds of 13q. The overall findings were similar to those usually found with partial duplication of chromosome 13. The ocular pathologic findings, including monocular spherophakia, were not suggestive of any known chromosomal syndrome, and their cytogenetic significance is not known. A review of 42 other cases of partial duplication 13 revealed a high (85%) incidence of ocular anomalies, most of which were comparatively minor or involved the ocular adnexa. Although ocular anomalies in this syndrome are associated with changes in different regions of chromosome 13, the major ones are usually associated with duplication of the proximal third of 13q and minor ones with the distal two-thirds of 13q.

Abnormalities, Multiple↗
PubMed1983

Position-dependent motor innervation of the chick hindlimb following serial and parallel duplications of limb segments.

In this paper we report investigations of the innervation of duplicated limb segments to test whether the addition of limb segments along the proximodistal axons could stimulate the growth of appropriate motoneurons into double occurrences of these muscles. Our evidence indicates that it does not. Using retrograde horseradish peroxidase nerve-tracing techniques and reconstructions of experimental limbs, we investigated the motor projection to parallel and serially duplicated legs. In all cases, host limb segments were normally innervated. In a control experiment involving a host thigh connected to a graft calf, the innervation of both segments was normal. In serially duplicated limb segments, however, we found abnormal innervation. In limbs of the type thigh-thigh-calf-foot, the innervation of the second thigh was accomplished by calf motoneurons. In limbs consisting of thigh-calf-calf-foot, the duplicated calf was served by foot motoneurons. The general pattern was that muscles were innervated as a function of their position along the proximodistal axis, irrespective of their identity. In no limb were axons found distal to the third limb segment even before the period of normal cell death. Despite the mismatched innervation with regard to the thigh/calf/foot distinction, axons retained their characteristic selectivity for either dorsally or ventrally derived muscles. The findings suggest that the projection of axons along the proximodistal axis of the limb is influenced by proximal growth cues associated with the formation of the limb plexus as well as by competitive interactions in the distal limb tissue.

Animals↗
PubMed1980

[Rare duplications of the alimentary tract (author's transl)].

Three rare cases of spherical duplication of the alimentary tract and a duplication with a pedicle associated with the ileum are reported. The treatment advocated for the duplication of the cervical oesophagus and of the ano-rectal region is the removal of the mucosa with suturing of the partially removed cyst edges. The rare intraluminous duplication of the pylorus can be removed by a duodenoantrostomy which can be performed easily in the new-born.

Anal Canal↗
PubMed1995

[Epipadiac duplication of the urethra].

Urethral duplication is a less frequent malformation. The Williams classification, which is currently admit, classifies them in sagital, hypospadias or complex and collateral duplications. They can be complete, incomplete or reduced to an incomplete sinus. The most severe cases are often accompanied by multi-abnormality syndromes. Clinical manifestations are various: asymptomatic, urinary infection, incontinence, double urinary stream,... We will report two new cases of incomplete epispadias duplication. The first case presents a purulent flow from the fistula, the second a frank epispadiac status. In both cases, corrective surgical treatment was performed, after a complete balance-sheet. The embryological, diagnostical and therapeutical aspects of the different forms of urethral duplication will be studied based on data from literature.

Child↗
PubMed1995

[Duplication of the digestive tract in children. Apropos of 12 cases].

Duplications of the gastro intestinal tract are characterised (Ladd and Gross) by the following histological features two muscular layers with myenteric cells inside. Cystic or tubular, they are always situated on the mesenteric border of the gastro intestinal tract with a common blood supply. The pathogenesis of duplication affects early fetal development via various mechanisms. Located anywhere along the alimentary tract as in our review of 12 cases, clinical manifestations vary according to the site. Abdominal cystic mass, mediastinal compression or intestinal obstruction bleeding or perforation are possible symptoms, but the presentation is very variable. The age of presentation is usually within the first year of life. The diagnosis can be made preoperatively by several investigations but the malformation is frequently discovered during surgery. Surgery is the only treatment for these duplications, but smaller cystic lesions are easily treated. However surgery of extensive duplications remains difficult.

Adolescent↗
PubMed1994

Partial duplication of the EGF precursor homology domain of the LDL-receptor protein causing familial hypercholesterolemia (FH-Salerno).

A novel mutation of low density lipoprotein (LDL)-receptor gene was found in an Italian family hypercholesterolemia (FH) patient during a screening of 300 FH patients. The proband as well as her daughter were found to be heterozygotes for the mutation. Binding, internalization, and degradation of 125I-labeled LDL by the proband's fibroblasts were reduced to approximately 50% compared to values found in control cells. DNA analysis by Southern blotting showed that the mutant allele was characterized by an insertion of about 10 kb, which resulted from a duplication of exons 9-14 of the LDL-receptor gene. In addition, Northern blot analysis of the proband's RNA showed, besides the normal sized LDL-receptor mRNA (5.3 kb), an additional mRNA of about 6.2 kb. The junction between exon 14 and the duplicated exon 9 was amplified by polymerase chain reaction (PCR) from the cDNA. The sequence of the amplified fragment showed that exon 14 joined the duplicated exon 9 without changing the reading frame. The derived amino acid sequence indicated that the mutated receptor protein had a partial duplication of the EGF precursor homology domain. Ligand and immunoblotting revealed that proband's fibroblasts contained one-half of the normal amount of LDL-receptor protein (molecular mass 130 kDa) and an abnormally large receptor of approximately 160 kDa. The amount of this abnormal receptor as detected by two monoclonal antibodies (10A2 and 4B3) was found to be approximately 30% that of the normal LDL-receptor present in the same cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

Two yeast chromosomes are related by a fossil duplication of their centromeric regions.

A 15 kbp fragment of the Saccharomyces cerevisiae genome was cloned and localised to the centromeric region of chromosome XIV by genetic linkage and DNA sequencing. It had a strong sequence similarity and a conserved gene linkage and transcriptional orientation relatively to the centromeric region of chromosome III, indicating a fossil interchromosomal duplication of several linked genes. On chromosome XIV, the duplicated fragment included the centromere, four genes (FUN34, CIT1 and two tDNAs), one open reading frame (DOM34) and a truncated delta element. Additional inserts bearing unique genes were present on the centromeric region of chromosome III. The level of silent substitutions indicated a relatively ancient genetic separation, pre-dating the emergence of S. cerevisiae and S. douglasii as distinct species. The ensuing evolution of the duplicated regions retained strict sequence identity for the two tDNAs pairs, but was partially divergent for CIT1 and FUN34, and generated a probable pseudogenic equivalent of DOM34 on chromosome III. Extant multigenic duplications of this type might play an important role in the evolution of eukaryotic genomes.

Centromere↗
PubMed1993

Extent of duplication in lower-limb malformations suggests the time of the teratogenic insult.

Investigations of vertebrate limb development have suggested that a process called "specification" instructs the cells of the future limb as to which tissues they should form. This process proceeds in a wave-like manner, starting at the most proximal levels of the future limb and ending at its distal tip. Human limb specification probably occurs during the fourth and fifth weeks of development. It is proposed that human limb duplications result from errors of specification and, furthermore, that the more distal the duplication, the later the occurrence of the teratogenic event during the specification process. Therefore, among human lower limbs with duplications, one may be able to estimate the relative time of the teratogenic event by comparing the levels at which the duplications occur.

Cell Polarity↗
PubMed1993

[Duplication of the small intestine. Unusual cause of abdominal pain].

Duplications of the alimentary tract are rare. Since 1982 only three patients with such anomalies have been treated in the Department of Paediatric Surgery at the University Hospital in Trondheim, Norway. We describe the last patient treated, where duplication of the ileum was found upon laparotomy, performed because of exaggerated recurrent abdominal pain. Duplications may be found anywhere along the alimentary tract and diagnosis can be difficult. The duplications can be found upon laparotomy for suspected appendicitis or bowel obstruction. The condition may also be suspected upon antenatal ultrasonography and in the event of abdominal symptoms after birth.

Abdomen, Acute↗
PubMed1993

Duplication of small segments within the major breakpoint cluster region in chronic myelogenous leukemia.

The t(9;22) in chronic myelogenous leukemia (CML) may be reciprocal or, in a minority of cases, may result in an extensive deletion of a portion of the major breakpoint cluster region (M-bcr) of the BCR. This report provides evidence of the duplication of small segments within the M-bcr in a small group of patients with CML. Southern blots of Bgl II and Bgl II/BamHI double-digested DNA from the blood or bone marrow of 46 patients with CML were probed with a 5' 1.4-kb Taq I/HindIII M-bcr probe and a 3' 2-kb HindIII/BamHI M-bcr probe. In three patients, rearrangements were noted with both probes in Bgl II-digested DNA, but were not present in Bgl II/BamHI-digested DNA with either probe. Southern analysis of DNA samples double-digested with Bgl II and BspHI from two of these three cases showed no rearrangements with either probe; the M-bcr BspHI site is located 26 bp 3' of the BamHI site in the second intron of the M-bcr. The presence of a rearranged M-bcr with both probes in Bgl II-digested DNA and the lack of rearrangement in Bgl II/BamHI and Bgl II/BspHI double-digested DNA suggest the presence of M-bcr BamHI and BspHI sites on both 9q+ chromosome (9q+) and the Philadelphia chromosome (Ph). This implies a duplication of at least the 26-bp M-bcr BamHI/BspHI fragment in these two samples. Sequence data from one of these two cases confirmed the M-bcr breakpoints to be staggered; the Ph M-bcr breakpoint occurred 258 bp downstream from the 9q+ M-bcr breakpoint. It is concluded that a duplication of small segments within the M-bcr occurs in a small group of patients with CML, which may lead to pseudogermline patterns on Southern blot. Such a duplication may provide insight into the mechanism of some chromosomal translocations in neoplasia.

Base Sequence↗
PubMed1993

Characterization of de novo duplications in eight patients by using fluorescence in situ hybridization with chromosome-specific DNA libraries.

Fluorescence in situ hybridization (FISH) with chromosome-specific DNA libraries was performed on samples from eight patients with de novo chromosomal duplications. In five cases, the clinical phenotype and/or cytogenetic evaluations suggested a likely origin of the duplicated material. In the remaining three cases, careful examination of the GTG-banding pattern indicated multiple possible origins; hybridization with more than one chromosome-specific library was performed on two of these cases. In all cases, FISH conclusively identified the chromosomal origin of the duplicated material. In addition, the hybridization pattern was useful in quantitatively delineating the duplication in two cases.

Aneuploidy↗
PubMed1993

[An exceptional combined malformation: duplication of the lower urinary tract, the vulva and the posterior intestine].

The authors report the case of a 6 year old girl with bladder duplication, urethral duplication, genital system duplication associated with colonic duplication and low double anorectal anomalies. This patient presented two hemivertebrae at T9 and T11. This girl died a few days after admission from internal obstruction and septicemia. The embryological features especially the possibility of associating two different embryopathogenic mechanisms in the pathogenesis of this combined malformation (Split notochord syndrome and fissure of the urogenital system), and diagnostic and therapeutic aspects are studied in relation to this case and a review of the literature.

Abnormalities, Multiple↗
PubMedDate not supplied

[A comparative analysis of UMUDC-dependent induction of tandem duplications, point and insertional reversions in Salmonella].

Comparative analysis of UV induction of tandem chromosome (Mtc+) duplications and reversions of point mutations (base pair substitutions) and of insertion mutations (precise excision of Tn10) was carried out. Salmonella (umuST) genes deficiency preventing dose-dependent UV induction of point mutation reversion were shown to have a less pronounced effect on the induction of tandem chromosome duplications. UV induction of tandem chromosome duplications is similar to UV induction of insertion mutation reversion: dose-dependent UV induction of both occurs in umuST Salmonella strains. E. coli umuDC+ genes included in Salmonella genome appreciably enhance the UV induction of both tandem duplications and insertion mutation reversion. The presence of umuDC+ genes ensures an expressed dose-dependent UV induction of point mutation reversion.

Chromosome Aberrations↗
PubMed1996

Common sheath reimplantation yields excellent results in the treatment of vesicoureteral reflux in duplicated collecting systems.

PURPOSE: We evaluated our 10-year experience with the surgical treatment of vesicoureteral reflux in uncomplicated duplicated collecting systems. MATERIALS AND METHODS: Between 1984 and 1994, 54 refluxing renal units (8 bilateral) in 37 female and 9 male patients required surgery. Patient age ranged from 7 months to 17 years (average 4.9 at surgery). Postoperative followup (average 14.2 months) included voiding cystourethrography and renal sonography or excretory urography. RESULTS: Common sheath ureteral reimplantation via an intravesical approach was performed in 48 of the 54 refluxing renal units. Of the remaining 6 renal units detrussorrhaphy was performed in 4, and ureteroureterostomy combined with ureteral reimplantation and partial lower pole nephrectomy were done in 1 each. Two treated renal units had persistent postoperative vesicoureteral reflux, which resolved after subureteral polytetrafluoroethylene (Teflon) injection. No renal had postoperative hydronephrosis. Contralateral reflux was identified in 1 patient who underwent unilateral reimplantation. Our overall success rate was 96% for the surgical correction of vesicoureteral reflux in uncomplicated duplicated collecting systems. Common sheath reimplantation had a 98% success rate. CONCLUSIONS: Although a duplicated collecting system increases the risk for surgical treatment, the presence of a duplication anomaly does not adversely affect surgical outcome. Modifications of procedures commonly performed in the surgical treatment of single system reflux to accommodate common sheath reimplantation have excellent surgical results with minimal morbidity.

Adolescent↗
PubMed1996

Duplication of the PMP22 gene in 17p partial trisomy patients with Charcot-Marie-Tooth type-1 neuropathy.

Autosomal dominant Charcot-Marie-Tooth type-1A neuropathy (CMT1A) is a demyelinating peripheral nerve disorder that is commonly associated with a submicroscopic tandem DNA duplication of a 1.5-Mb region of 17p11.2p12 that contains the peripheral myelin gene PMP22. Clinical features of CMT1A include progressive distal muscle atrophy and weakness, foot and hand deformities, gait abnormalities, absent reflexes, and the completely penetrant electrophysiologic phenotype of symmetric reductions in motor nerve conduction velocities (NCVs). Molecular and fluorescense in situ hybridization (FISH) analyses were performed to determine the duplication status of the PMP22 gene in four patients with rare cytogenetic duplications of 17p. Neuropathologic features of CMT1A were seen in two of these four patients, in addition to the complex phenotype asociated with 17p partial trisomy. Our findings show that the CMT1A phenotype of reduced NCV is specifically associated with PMP22 gene duplications, thus providing further support for the PMP22 gene dosage mechanism for CMT1A.

Blotting, Southern↗
PubMed1996

[Primary adenocarcinoma of renal pelvis and ureter associated with incomplete ureteral duplication: a case report].

We report a rare case of primary adenocarcinoma of the renal pelvis and ureter in an incomplete duplicated ureter. A 69-year-old male with macroscopic hematuria consulted our hospital. Retrograde pyelography revealed left incomplete duplicated ureter and a filling defect in the lower pole of the ureter. Transurethral ureteroscopy was employed to investigate the filling defect, and a papillary tumor was detected extending into the lower segment of the incomplete duplicated ureter. From these findings, the patient was diagnosed with tumor of renal pelvis and ureter, and left total nephroureterectomy was performed. Pathological diagnosis was adenocarcinoma of the renal pelvis and ureter, INF beta, pT2, pR0, pL0, PV0, PN0. No evidence of either tumor recurrence or metastasis was found on the 3-month postoperative follow up. This case is thought to be the first report of primary adenocarcinoma of the renal pelvis in an incomplete duplicated ureter.

Adenocarcinoma↗
PubMed1996

[Gastric duplication or pancreatic pseudocyst. Diagnostic difficulties apropos of a case].

Gastric duplication was diagnosed in a 50 year-old patient who was initially thought to have a pancreatic pseudo-cyst until laparotomy was performed. There are many clinical and radiological similarities between gastric duplication and pancreatic pseudo-cyst. However, the following elements can suggest the diagnosis of gastric duplication in the case of the discovery of a cystic mass in the gastric or pancreatic area: normal pancreatic enzyme levels, ultrasonic identification of a hyperechoic inner rim and a hypoechoic outer rim with peristaltic movements into the cyst, visualization of a communication between the cyst and the gastro-intestinal tract, and detection of associated vertebral abnormalities. Surgical treatment of gastric duplication is only necessary in symptomatic cases.

Diagnosis, Differential↗