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Biomedical subjects

J Bal

Publications and source records attributed to J Bal.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Inter-generational transmission of mutations responsible for fragile X syndrome].

Inter-generational transmission of normal and mutated (CGG)n sequences in the FMR1 gene was studied in 17 Polish fragile X families. All normal alleles were stable when transmitted to the progeny. Twenty-five of the 26 transmitted maternal premutations expanded to full mutation level. No correlation between the number of CGG repeats in the maternal premutation and the size of the mutation in the offspring was found. Analysis of the mutation size in siblings revealed that the length of full mutations is sex-dependent. The average length of the (CGG)n sequence in sons of fragile X female carriers was larger than in daughters.

Alleles↗
PubMed1995

Chondrosarcoma in a patient with relapsing polychondritis.

A case of a chondrosarcoma in a patient with relapsing polychondritis was presented. The association of these two unusual disorders of cartilaginous tissue has never been described before. The clinical presentation and radiologic and histologic features were discussed.

Bone Neoplasms↗
PubMed1995

[A study evaluating the correlation between the phenotype and genotype among 65 cystic fibrosis patients].

Among 65 CF diagnosed patients with both CFTR gene mutations known genotype-phenotype studies were performed. Correlation between pancreatic insufficiency and so called "severe mutations" was found. Respiratory tract symptoms do not seem to depend on one specific mutation as well as meconium ileus is not only limited to the group of patients with delta F508/delta F508 genotype. Some other genotype - clinical features correlation in CF patients are discussed.

Adolescent↗
PubMed1992

Simple non-radioactive detection of the CFTR mutation N1303K by artificial creation of a restriction site.

N1303K is one of the most frequent non-delta F508 mutations causing cystic fibrosis in Central Europe. Since no restriction site is altered by this mutation and no other frequent mutations are known so far in exon 21, the detection requires a separate and laborious test. A mismatched primer was used to create an artificial Hin dIII site in amplified wildtype DNA, which is destroyed by the mutation. This allows for rapid and convenient detection by restriction enzyme digestion.

Base Sequence↗
PubMed1992

[Martin-Bell syndrome. Improved possibilities for molecular genetic diagnosis].

In a former molecular segregation analysis of fra x mental retardation in 27 families at risk we had used marker gene probes with a relatively high recombination fraction. Thus, the resulting risk for a false diagnosis was comparatively high. To diminish this risk, all families were reanalyzed with the newly invented and more closely linked gene probes RN1A, VK23B, VK21C and U6.2. Using these probes as molecular markers we performed Southern hybridization experiments. The remaining diagnostic risk due to recombination events could be reduced to 2% up to 20% compared to preanalysis. The portion of informative families (91%) is in good agreement with the expected cumulative heterozygosis frequency of 93.4% for all 4 markers investigated. This high frequency and the very low remaining risk for a false diagnosis therefore enable a far more precise molecular diagnostic of the Martin-Bell-syndrome.

Abnormalities, Multiple↗
PubMed1991

Discrimination between recurrent mutation and identity by descent: application to point mutations in exon 11 of the cystic fibrosis (CFTR) gene.

A total of 75 non-delta F508 chromosomes from 59 German cystic fibrosis patients was screened for mutations in exon 11 of the cystic fibrosis (CFTR) gene. These Caucasian patients were found to possess an identical haplotype background for two common mutations (G551D, R553X) consistent with their being identical by descent. However, a different R553X associated haplotype found in American black patients was suggestive of recurrent mutation, a postulate supported by the location of the R553X alteration in a hypermutable CpG dinucleotide. Likelihood estimates for recurrent mutation and identity by descent were compared and strongly supported the hypothesis of recurrent R553X mutation. The ability to distinguish between these two alternatives provides an indication of whether or not the search for mutations should be restricted to chromosomes with similar haplotypes.

Cystic Fibrosis↗
PubMed1991

A cystic fibrosis patient homozygous for the nonsense mutation R553X.

A cystic fibrosis patient homozygous for the nonsense mutation R553X was identified by mutation screening and the genotype confirmed by DNA sequencing. This patient, the only one described to date who is homozygous for this stop codon in exon 11 of the CFTR gene, is moderately severely affected. Clinical and molecular findings are presented.

Alleles↗
PubMed1989

Different haplotypes for cystic fibrosis-linked DNA polymorphisms in Polish and Dutch populations.

We analyzed DNA from 34 Polish and 63 Dutch cystic fibrosis (CF) patients and their families using the polymorphic markers XV2c and KM19, which are in linkage disequilibrium with the CF mutation. Strong linkage disequilibrium was found in the Dutch population sample, but the haplotypes of the Polish chromosomes showed a significantly less extreme disequilibrium. Our data and previous studies indicate that the highest degree of homogeneity of the CF defect and hence the best possible use of the XV2c/KM19/CF linkage disequilibrium for CF carrier detection/exclusion is in populations of northern European origin.

Cystic Fibrosis↗