Lethal polymalformative syndrome with 13q deletion secondary to a maternal X; 13 translocation

The authors report the case of a newborn full term delivered by cesarean section for evolutive hydrocephalus, in the last month of pregnancy. This hydrocephalus was confirmed by echography after birth. This also having ambiguous genitalia and atresia ani, he died a few hours later. No evidence of infectious or toxic embryofetopathy was found out as an etiologic factor, but the karyotype of the baby showed a 13 q deletion and that of the mother a non reciprocal Xqter; 13q31.3 translocation. The study of inactivation of X indicated that the inactivated X chromosome in each cell was normal. On this occasion, the authors try to bring together the main points of "13q-syndrome" and discuss on the practical approach of antenatal diagnosis which they could propose to the couple.     

Characterization of microsatellites from flow-sorted porcine Chromosome 13

Porcine flow-sorted Chromosome (Chr) 13 was PCR amplified with primers based on porcine short interspersed element (SINE) sequences. The product was cloned, gridded in microtiter plates, and screened with a [GT]₁₀ oligonucleotide which gave 45 positive clones. Sequencing of these clones showed that 36 were unique, and 26 [GT]_n microsatellites were characterized. Six other simple repeat sequences, the majority of which were associated with the 3 end of the SINE sequence, were also detected. Twenty-one primers sets were selected, and 13 of these detected useful polymorphisms in the grandparents (n=26) of the European porcine mapping collaboration (PiGMaP) reference families. These 13 markers were mapped in the PiGMaP reference families, and a two-point linkage analysis was performed. The Lod scores indicated that three of the markers were not linked and the remaining 11 formed two linkage groups of two and nine markers respectively. The larger linkage group was also linked to the transferrin locus, permitting assignment of nine markers to porcine Chr 13.The nucleotide sequence data reported in this paper will appear in the EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accession numbers: X79915, 13N14F; X79916, 13N17R; X79917, 13N18R; X79918, 13N32R; X79919, 13R33R; X79920, 13R33U; X79921, 13R43U; X79922, 13R44R; X79923, 13N03R; X79924, 13N04R; X79925, 13N05R; X79926, 13N06R; X79927, 13N12U     

Translocation (X;13)(p11.21;q12.3) in a girl with incontinentia pigmenti and bilateral retinoblastoma

A de novo t(X;13)(p11.21;q12.3) translocation is described in an 19-month-old girl with incontinentia pigmenti (IP) and bilateral retinoblastoma. Based on previously reported two girls and this patient, each with a structural X chromosome abnormality and IP, it was assumed that the locus for IP is at Xp11.21. Q-banding analysis revealed that the translocated chromosomes were of paternal origin. The derivative X chromosome was late-replicating in 9% of cultured peripheral blood lymphocytes and in 1% of skin fibroblasts. The erythrocyte esterase D activity in the patient was normal. Several possibilities were considered for possible causative relationship between the X/13 translocation and the development of retinoblastoma. One possibility involved functional monosomy of 13q14 in a minority of retinoblasts due to the spreading of inactivation of the translocated X chromosome segment.     

A case of (13q;18q) translocation with proximal 13q monosomy

Summary A case of partial monosomy of the 13p terminal to 13q12, associated with a de novo 13/18 translocation, is reported. The symptoms appeared to be derived from both 18q- and partial monosomy 13, the latter giving rise to: high arched palate, epicanthus, antimongolian slant, small eye fissure, flat nasal bridge, hypoplastic helix, and large clitoris. Serum Ig-A and Ig-M levels were normal in our case.     

Chromosome landing near avirulence gene vH13 in the Hessian fly.

AFLP markers in linkage disequilibrium with vH13, an avirulence gene in the Hessian fly (Mayetiola destructor) that conditions avirulence to resistance gene H13 in wheat (Triticum spp.), were discovered by bulked segregant analysis. Five AFLPs were converted into codominant site-specific markers that genetically mapped within 13 cM of this gene. Flanking markers used as probes positioned vH13 near the telomere of the short arm of Hessian fly chromosome X2. These results suggest that the X-linked avirulence genes vH6, vH9, and vH13 are present on Hessian fly chromosome X2 rather than on chromosome X1 as reported previously. Genetic complementation demonstrated that recessive alleles of vH13 were responsible for the H13-virulence observed in populations derived from four different states in the U.S.A.: Georgia, Maryland, Virginia, and Washington. Results support the hypothesis that a gene-for-gene interaction exists between wheat and Hessian fly.     

Trisomy 13 with a 13q14q translocation.

A sporadic case of Patau syndrome with 46,XY,14-,t(13q14q)+ karyotype is reported in a 2-month-old child. Dermatoglyphic and cytogenetic findings of the propositus and cytogenetic study of his parents are presented.     

The structural gene for human coagulation factor X is located on chromosome 13q34

The gene coding for coagulation factor X was studied in a family segregating chromosomal abnormalities involving chromosomes 13 and 6. An individual monosomic for 13q34 was deficient in levels of clotting factors VII and X, while her brother, who is trisomic for 13q34, had elevated levels. DNA dosage studies with a cloned human factor X gene demonstrated that the low levels of factor X expression in the individual with the chromosome 13q34 deletion were due to the absence of one copy of the factor X structural gene. This confirms the assignment of the human gene coding for factor X to 13q34.     

13C-NMR study of the binding of [1-13C]galactose-labelled N-acetyllactosamine and [1-13C]galactose-enriched hen ovalbumin to soybean agglutinin

The binding of the tide compounds to soybean agglutinin was investigated using 13C-NMR spectroscopy. The equilibrium constant for the binding of N-acetyllactosamine was found to be smaller than that obtained for the binding of ovalbumin (1.1 X 10(3) vs. 7.4 X 10(3) M-1). Only two binding sites per lectin tetramer were determined for the binding of ovalbumin, which is half the number of binding sites reported for the binding of small ligands to the lectin. Steric interference between the bulky ovalbumin molecules is believed to be the reason for the observed decrease in the apparent number of binding sites on the lectin.     

Two cases of terminal deletion of chromosome 13: clinical features, conventional and molecular cytogenetic analysis

We report the cases of two unrelated patients with psychomotor retardation and craniofacial abnormalities, in whom cytogenetic studies have revealed a terminal deletion of chromosome 13 confirmed by fluorescence in situ hybridization (FISH). This del(13)(q33.2) is the smallest terminal deletion of the 13q reported so far. Interestingly enough, the serum level of coagulation factors VII and X, whose genes are located in 13q34, were reduced in both patients. These cases illustrate the difficulties in identifying precisely chromosome deletions and demonstrate that FISH techniques allow to obtain a more precise correlation between clinical phenotype and cytogenetic abnormalities.     

Chromosome analysis of spermatozoa from a male heterozygous for a 13;14 Robertsonian translocation

Summary Cytogenetic analysis of 78 spermatozoa from a man heterozygous for a t(13;14) Robertsonian translocation was performed. R banding was applied for chromosomal identification. Incidence of normal and balanced complements were respectively 50% and 41.3%. Six unbalanced complements (7.7%) were observed, resulting from adjacent segregation. Although alternate segregation is the most common mode of distribution, the possibility of producing unbalanced zygotes exists. The frequency of abnormalities unrelated to the translocation was 16.5% including 12.8% hypohaploïdy, 2.5% hyperhaploidy, and 1.2% of structural aberrations. An excess of t(13;14) X complements was observed (24 with X versus 14 with Y). This may result from the close association between trivalent (13;14) and X chromosome observed in the pachytene spermatocyte nucleus.     

Inversion of chromosome 2 (p11p13): Frequency and implications for genetic counselling

Summary We report a case of an X-autosome translocation t(X;4)(q13;p16) found in both sexes in three generations. The anomaly was diagnosed in a couple referred for cytogenetic investigation as a result of three spontaneous abortions. With the exception of the miscarriages there are no particularities in the gynecologic data of the woman or in the pedigree. In all 50 lymphocytes and in 66 of 68 fibroblasts investigated the normal X chromosome was the late replicating one.     

A dysmorphic newborn with 45,X,der(1)inv(1)(p13;qter)t(Y;1)(pter-->q11;p13),-Y de novo karyotype

A dysmorphic newborn with 45,x,der(1)inv(1)(p13;qter)t(y;1)(pter-->q11;p13),-Y de novo karyotype: Y/autosome translocations are very rare chromosomal rearrangements. In most cases, the long arm of the Y chromosome is translocated onto an autosome and most patients are referred because of male infertility. Y/1 translocations are very rare, and have been reported in seven patients so far. Pericentric inversions may be seen in all chromosomes and are not associated with phenotypic abnormalities. Here we report a 6-day old male baby with prenatal growth retardation, frontal bossing, hypertelorism, micrognathia, cleft soft palate, absent uvula, hypospadias, simian line in both hands and hammer toes. Cytogenetic analysis was performed with GTG-banding, C-banding and FISH analysis containing X centromeric probe, Yq12-qter locus specific probe and whole chromosome Y probe. An unbalanced Y/1 translocation was diagnosed: 45,X,der(1)inv(1)(p13;qter)t(Y;1)(pter-->q11;p13),-Y.     

First prenatally detected small supernumerary neocentromeric derivative chromosome 13 resulting in a non-mosaic partial tetrasomy 13q

Neocentromeres are functional centromeres located in non-centromeric euchromatic regions of chromosomes. The formation of neocentromeres results in conferring mitotic stability to chromosome fragments that do not contain centromeric alpha satellite DNA. We present a report of a prenatal diagnosis referred to cytogenetic studies due to ultrasound malformations such as large cisterna magna, no renal differentiation, hypotelorism and ventriculomegaly. Cytogenetic analysis of GTG-banded chromosomes from amniotic fluid cells and fetal blood cells revealed a de novo small supernumerary marker chromosome. Molecular cytogenetic studies using fluorescence in situ hybridization and comparative genomic hybridization showed this marker to be an inverted duplication of the distal portion of chromosome 13q which did not contain detectable alpha satellite DNA. The neocentromeric constriction was located at band 13q31. The presence of a functional neocentromere on this marker chromosome was confirmed by immunofluorescence with antibodies to centromere protein-C. The anatomopathologic study revealed a female fetus with facial dysmorphisms, low set ears and renal dysplasia. Ten small supernumerary neocentromeric chromosomes originating from the distal region of chromosome 13q have been reported to date. There are only three additional cases described with the location of the neocentromere in band 13q31. This is the first reported case detected prenatally.     

A case of D13 ring chromosome

Summary A case of D ring chromosome identified with trypsin banding as a 13 with loss of the bands p12 and q34 is reported. The clinical features characteristically associated with the loss of these specific segments were present.     

Congenital heart defect and mental retardation in a patient with a 13q33.1-34 deletion

13q deletion syndrome is a rare genetic disorder caused by deletions of the long arm of chromosome 13. Patients with 13q deletion display a variety of phenotypic features. We describe a one-year-old female patient with congenital heart defects (CHD), facial anomalies, development and mental retardation. We identified a 12.75Mb deletion in chromosome region 13q33.1-34 with high resolution SNP Array (Human660W-Quad, Illumina, USA). This chromosome region contains about 55 genes, including EFNB2, ERCC5, VGCNL1, F7, and F10. Comparing our findings with previously reported 13q deletion patients with congenital heart defects, we propose that the 13q33.1-34 deletion region might contain key gene(s) associated with cardiac development. Our study also identified a subclinical deficiency of Factors VII and X in our patient with Group 3 of 13q deletion syndrome.     

Autopsy Report of a 7-Year Old Patient with the Mosaic Trisomy 13

We present here a long survival case of a patient with the mosaic form of trisomy 13 who died of aspiration pneumonia at the age of 7 years and 4 months. The autopsy revealed olfactory aplasia and fenestration of the septum pellucidum, and dilated lateral ventricles and atrophic hippocampus. Furthermore, there were numerous “torpedos” (i.e., swollen fusiform Purkinje cell axons), mostly in the granular layer underneath the Purkinje cell layer, and, occasionally, in the granular layer. Similar neuropathological findings have been reported in elderly cases of essential tremor, Parkinson’s disease, or Alzheimer’s disease. Precise mechanism for this axonal change is still unclear. These pathological changes have never previously been reported in the literature on trisomy 13, and the present patient is one of the oldest autopsied individuals with the mosaic trisomy 13.     

DNA heteroduplex analysis of the relation between bacteriophages phiX174 and S.13

When observed in the electron microscope using the isodenaturing methods of Davis &; Hyman (1971), only one small segment (4.7 ± 1.9%) of the DNA of phage φX174 is highly homologous with phage S.13 DNA; the rest is partially homologous with an over-all average 36% base mismatch. The two phage DNA molecules appear to be identical in length and have no regions of complete base non-homology. The phage-coded proteins were compared by electrophoresis on slab polyacrylamide gels and only one of the S.13 coded proteins migrated identically with its φX174 counterpart. The other eight S.13 coded proteins varied in size from their φX174 counterparts by +4.6% to ?6.0% (± ten amino acid residues). The relevance of these data to the complementation and recombination between these two phages is discussed.     

In vivo 13C-NMR studies of polymer synthesis in rhizobium meliloti M5N1 strain

The use of in vivo 13C-NMR approach for the monitoring of the synthesis of various polymers within cells of Rhizobium meliloti (M5N1 strain) is reported. Significant differences in polymer biosynthesis have been shown as a function of the metabolic state of the cells and the labeled carbon source used. Consumption of carbon source and produced glycogen was complete with mid-exponential phase harvested cells. This was not the case with stationary phase harvested cells, for which polyhydroxybutyrate synthesis was higher and gluconate synthesis was lower than the former. [1-13C]fructose-grown cells produced more exopolysaccharide and polyhydroxybutyrate, but less beta-(1,2) glucan and gluconate than [1-13C]glucose-grown cells. This approach offers a suitable tool to examine the kinetics of polymer biosynthesis by Rhizobia. Copyright 1998 John Wiley & Sons, Inc.     

M13 endopeptidases: New conserved motifs correlated with structure,and simultaneous phylogenetic occurrence of PHEX and the bony fish

M13 endopeptidase alignments have focused mainly on mammalian sequences and on the active site region defining the catalytic sequence signatures. Aligning all available M13 from bacteria to human on a full-length basis, we have performed a sequence analysis. This enabled us to highlight the origin and function of the M13 PHEX subtype family endopeptidase (phosphate regulating gene with homologies to endopeptidases on the X chromosome). New evolutionary conserved regions in both prokaryotes and eukaryotes have been detected and eukaryotic-specific regions clearly delineated. Using the recently solved neprilysin structure, we have observed that all new motifs, except one, localize in the spatial vicinity of the previously reported catalytic signatures. Interestingly, a highly hydrophobic pocket containing three newly reported motifs is centered by the C-terminal tryptophan residue. Extensive M13 searches in complete and in progress higher eukaryotic genomes have lead to the identification of Danio rerio as the simplest organism having PHEX. Finally, the human PHEX substrate, the parathyroid hormone-related peptide, PTHrP(107-139), is absent in bony fish: this suggests the existence of further PHEX substrates common to both bony fishes and higher vertebrates.