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Biomedical subjects

B Jay

Publications and source records attributed to B Jay.

At least 19 recordsLinked to original sources
PubMed1992

Relapse following goniotomy for congenital glaucoma due to trabecular dysgenesis.

Three hundred and thirty-five eyes of 210 patients with congenital glaucoma due to trabecular dysgenesis were treated by goniotomy as the primary procedure in infancy. In 313 eyes (93.5%) glaucoma was controlled at one year following surgery. Using Kaplan Meier actuarial survival analysis we found that eyes controlled in infancy by one or more goniotomies are at risk of relapse of glaucoma for at least 15 years although 93% of eyes are still controlled five years after the initial surgery. Patients whose symptoms of congenital glaucoma presented at birth were more likely to relapse than those whose symptoms developed in the first few months of life. Eyes requiring multiple goniotomies in infancy were more likely to relapse than those controlled by a single procedure.

Follow-Up Studies↗
PubMed1992

Nine generations of a family with autosomal dominant retinitis pigmentosa and evidence of variable expressivity from census records.

We present a nine generation family with autosomal dominant retinitis pigmentosa (ADRP). Evidence of blindness in the early generations, as obtained from census returns and clinical records, and examination of current patients show variable expressivity with a spectrum which ranges from asymptomatic in late life to blindness in the third decade of life. The family is not linked to any of the chromosomal locations so far described in ADRP and further illustrates the heterogeneity of the disorder.

Adolescent↗
PubMed1991

Autosomal dominant retinitis pigmentosa: four new mutations in rhodopsin, one of them in the retinal attachment site.

Several mutations in the rhodopsin gene in patients affected by autosomal dominant retinitis pigmentosa (ADRP) have recently been described. We report four new rhodopsin mutations in ADRP families, initially identified as hetero-duplexed PCR fragments on hydrolink gels. One is an in-frame 12-bp deletion of codons 68 to 71. The other three are point mutations involving codons 190, 211, and 296. Each alters the amino acid encoded. The codon 190 mutation has been detected in 2 from a panel of 34 ADRP families, while the remaining mutations were seen in single families. This suggests that, consistent with a dominant condition, no single mutation will account for a large fraction of ADRP cases. The base substitution in codon 296 alters the lysine residue that functions as the attachment site for 11-cis-retinal, mutating it to glutamic acid. This mutation occurs in a family with an unusually severe phenotype, resulting in early onset of disease and cataracts in the third or fourth decade of life. This result demonstrates a correlation between the location of the mutation and the severity of phenotype in rhodopsin RP.

Amino Acid Sequence↗
PubMed1991

Genetic localisation of the RP2 type of X linked retinitis pigmentosa in a large kindred.

Genetic linkage and deletion studies have led to the proposal that there are at least two loci on the X chromosome which are responsible for X linked retinitis pigmentosa (XLRP). One locus (RP3) has been closely defined by genetic linkage and deletion analyses and localised to the region between the ornithine transcarbamylase (OTC) and chronic granulomatous disease (CYBB) loci in Xp21.1-p11.4. The other locus (RP2) has been assigned by linkage analysis alone to region Xp11.4-p11.2, but its localisation is less well defined. The results of a multipoint linkage analysis of a single large XLRP kindred using eight informative loci provide further evidence on the localisation of RP2 to this region. The maximum likelihood location of this locus shows a multipoint lod score of 7.17 close to DXS255 (in Xp11.22) and TIMP (in Xp11.3-p11.23), neither of which show recombination with RP2, in an area extending from 2 cM proximal to DXS7 to 1 cM distal to DXS14 (approximate 95% confidence limits).

Bayes Theorem↗
PubMed1990

No evidence for linkage between late onset autosomal dominant retinitis pigmentosa and chromosome 3 locus D3S47 (C17): evidence for genetic heterogeneity.

Retinitis pigmentosa is an inherited form of blindness caused by progressive retinal degeneration. P. McWilliam et al. (1989, Genomics 5: 619-622) demonstrated close genetic linkage between autosomal dominant retinitis pigmentosa (ADRP) and locus D3S47 (C17) in a single early onset pedigree. The marker C17 maps to the long arm of chromosome 3. Clinically, the disease phenotype has been subdivided into at least two forms on the basis of age of onset, as well as electrodiagnostic criteria. We demonstrate that C17 is unlinked in a late onset pedigree, indicating that the phenotypic variation seen reflects underlying genetic heterogeneity.

Chromosomes, Human, Pair 3↗
PubMed1990

Linkage studies and deletion screening in choroideremia.

Fourteen families with choroideremia (TCD) have been examined for linkage to nine genetic markers located on the proximal long arm of the X chromosome. Linkage to three markers (DXYS1, DXS72, DXS3) located in Xq21 was found with a four point lod score of 8.25. No evidence of submicroscopic deletions was observed using DXS233 and DXS232, both thought to lie within about 1 Mb of the TCD gene.

Choroideremia↗
PubMed1990

Deletions in patients with classical choroideremia vary in size from 45 kb to several megabases.

Making use of the p1bD5 probe (DXS165), we have isolated several markers from the choroideremia locus by chromosomal jumping, preparative field-inversion gel electrophoresis, and cloning of a deletion junction fragment. With these clones we were able to identify and characterize eight deletions in 69 choroideremia patients investigated. The deletions are heterogeneous, in both size and location. The smallest deletion (patient LGL1134) comprises approximately 45 kb of DNA, whereas the largest ones (patients 25.6 and LGL2905) span a DNA segment of at least 5 megabases, which is comparable in size to the smallest deletion detected in a TCD patient (patient XL45) showing a complex phenotype. The TCD deletions encompass variable parts of 150-200-kb DNA segment that is flanked by p1bD5 (DXS165) at the centromeric side and by pZ 11 at the telomeric side. The deletions in patients 33.1, LGL1101, and LGl1134 do not span a translocation breakpoint which was previously mapped on the X chromosome of a female with TCD. The clones isolated from the TCD locus are valuable diagnostic markers for deletion analysis of patients or carrier females. In addition, they should be useful for the isolation of expressed sequences that are part of the TCD gene.

Blotting, Southern↗
PubMed1988

Colour discrimination in pseudophakia.

A study was undertaken to examine the colour discrimination of fifty pseudophakic patients and to compare results with fifty age matched normal observers. Using the Farnsworth-Munsell 100-Hue test and Desaturated panel D15, performance does not differ significantly from the age matched normals, although a theoretically superior colour discriminative ability might be expected in pseudophakia. A slight trend for increasing error scores with advancing age in pseudophakia lends some support to the importance of neural factors in the ageing of colour discrimination. Several other factors influencing colour vision in pseudophakia are discussed.

Aged↗
PubMed1987

Prenatal diagnosis of X-linked choroideremia with mental retardation, associated with a cytologically detectable X-chromosome deletion.

We describe a family in which an X-chromosome deletion is segregating with choroideremia, and X-linked recessive condition. The DNA sequences DXYS1 and DXS3, defined by the probes pDP34 and 19.2 respectively, are absent in the affected male (who is also mentally retarded), and hemizygous in his mother and in his carrier sister, who presented early in pregnancy. Analysis of chorionic villus DNA formed the basis of prenatal exclusion of choroideremia in her male fetus. In three female relatives, studied with late-labelling techniques, the deleted X was preferentially inactivated in 86-100% of cells studied. This family confirms the localisation of the choroideremia locus to within Xq13----21, and places the loci for anhidrotic ectodermal dysplasia and the X-linked immunodeficiencies outside this region.

Choroid↗
PubMed1987

Molecular genetic approaches to the analysis of human ophthalmic disease.

In this review of the recent literature, the contribution that the new techniques of molecular genetics has made in the analysis and diagnosis of human ophthalmic conditions is presented and discussed. Among the disorders reviewed are X-linked retinitis pigmentosa, Norrie's disease, gyrate atrophy and retinoblastoma, and there are also sections on crystallins and visual pigments.

Chromosome Mapping↗
PubMed1987

Linkage relationships between X-linked retinitis pigmentosa and nine short-arm markers: exclusion of the disease locus from Xp21 and localization to between DXS7 and DXS14.

Linkage data between X-linked retinitis pigmentosa (XLRP) and nine X-chromosomal markers are reported. To test the assignment of XLRP to the Xp21 region (as considered at Human Gene Mapping 8), an analysis of XLRP and six markers flanking this region was undertaken. The XLRP locus was found to be excluded from the chromosome distal to ornithine transcarbamylase (OTC) (P = 6.5 X 10(-5]. Further data were accumulated with three more probes proximal to DXS7 (L1.28), the closest linked probe. Multipoint analysis of these data suggests a posterior probability of .94 that XLRP is proximal to DXS7 (L1.28), which has been mapped to the region Xp11.3.

Chromosome Mapping↗
PubMed1986

A genetic linkage study of choroideremia.

One hundred and twenty-two members of 15 choroideremia families have been used in a genetic linkage study of choroideremia (TCD) using four DNA probes situated on the X chromosome. Linkage was analysed using DNA probes DXS14 (p58-1), DXYS1 (pDP 34), DXS178 (p212) and DXS177 (lambda 2.7). Statistically significant linkage was demonstrated with DXYS1 (theta = 0.00, lod 4.95), in agreement with the findings of Nussbaum et al. (1985). Evidence consistent with loose linkage to TCD was also found with DXS14 (theta = 0.31, lod 0.23), DXS178 (theta = 0.18, lod 1.41) and DXS177 (theta = 0.27, lod 0.20). The results suggest that TCD is located in the region Xq13-q21. Probe DXYS1 is likely to prove useful in the prenatal diagnosis of this condition.

Choroid↗
PubMed1985

Plasma 5-S-cysteinyldopa concentrations in oculocutaneous albinism.

5-S-cysteinyldopa concentrations were determined by high-pressure liquid chromatography and electrochemical detection in plasma from normally pigmented patients and patients with oculocutaneous albinism, both tyrosinase-positive and tyrosinase-negative. The plasma 5-S-cysteinyldopa concentrations were similar in all three groups, suggesting that 5-S-cysteinyldopa can be produced by mechanisms which do not involve tyrosinase.

Albinism↗
PubMed1985

X-linked retinal disorders and the Lyon hypothesis.

The heterozygous states in X-linked ocular albinism, choroideremia and X-linked retinitis pigmentosa are described. Their fundus appearances differ, to a greater or lesser extent, from those of hemizygous (affected) males and a possible explanation for these differences is briefly discussed.

Adult↗