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Biomedical subjects

J L Watt

Publications and source records attributed to J L Watt.

At least 37 records · Page 2Linked to original sources
PubMed1987

Trisomy 1 in an eight cell human pre-embryo.

The high incidence of chromosome abnormalities in clinically recognised pregnancies is well documented, but experience of these problems at the time of conception is extremely limited. Using donated oocytes from women seeking surgical sterilisation, we have established reliable cytogenetic techniques for chromosome analysis of human pre-embryos. These have resulted in the first report of trisomy 1. The pre-embryo showed no other obvious abnormality in relation to follicular characteristics, embryo morphology, and cleavage kinetics. The usefulness of such data in explaining the high incidence of occult human pregnancy loss and the current poor success following embryo replacement is emphasised.

Chromosome Banding↗
PubMed1987

Structural rearrangements in the parents of children with primary trisomy 21.

A retrospective cytogenetic study was carried out on the parents of children with regular trisomy 21 Down's syndrome. In a total of 128 parents referred routinely to our laboratory after the birth of their affected child, three structural abnormalities, a reciprocal translocation and two pericentric inversions not involving chromosome 21, were detected. This is about 10 times the frequency expected based on current figures from consecutive newborn studies. In addition, the brother of one of nine older people with trisomy 21 referred for cytogenetic analysis for the first time was found to have a reciprocal translocation. This supports the contention made by others that an interchromosomal effect does exist in man. It is suggested that centres who routinely analyse the parents of their trisomy 21 referrals in an unbiased fashion should review their records. They will almost certainly contain useful information regarding the possible existence of this phenomenon and may even contain clues as to its nature. In addition to its undoubted scientific value, such data should prove useful in the genetic counselling of carriers of structural rearrangements.

Chromosome Aberrations↗
PubMed1986

Variation of SCE frequency in lymphocyte cultures from patients with Hodgkin's disease before, during, and after treatment.

Seven patients with newly-diagnosed Hodgkin's disease, having standard mustine-vinblastine-prednisolone-procarbazine therapy, had a large and regular pattern of rise in SCE frequency in their peripheral lymphocytes, which apparently started to fall before the end of the course (32 wk). In contrast, SCE frequency fell below normal in the lymphocytes of nine patients having mantle radiotherapy. Twenty-eight patients studied 2-13 yr after initial chemotherapy or radiotherapy for Hodgkin's disease had normal or near normal SCE frequencies.

Adult↗
PubMed1986

Cytogenetic analysis in 100 spontaneous abortions in North-East Scotland.

The results of an extremely detailed cytogenetic analysis on 100 spontaneous abortions occurring in the Aberdeen area over a 3 year period is presented. A comparison with other published series reveals that there is a higher culture success rate (93%) accompanied by a lower incidence of trisomy and a higher incidence of triploidy, although the percentage of chromosomally abnormal foetuses in first trimester abortions is comparable with other studies. However, these apparent discrepancies can largely be explained on the basis of gestational age and sampling variation.

Abortion, Spontaneous↗
PubMed1986

Chorion in culture.

This study is based on the processing of 115 samples of pure chorion. The different types of colony morphology, together with cytogenetic analysis, indicate the predisposition of chorion cells to artefacts of culture. Chorion survives longer than other foetal tissues and can be cultured when those are dead or contaminated (e.g. in macerated foetuses and missed abortions) making it a suitable and popular tissue for cytogenetic purposes. However, our results indicate that it is slow in culture and prone to chromosome variation so that pseudomosaicism frequently arises and may lead to misdiagnosis. We therefore suggest that cytogenetic analysis of spontaneous abortion material is interpreted with caution in cases where chorion is the only tissue cultured, especially when mosaicism is found.

Cell Division↗
PubMed1986

A paracentric inversion of 7q illustrating a possible interchromosomal effect.

A family is described in which the proband has a rearranged X chromosome involving monosomy Xp and trisomy Xq, while the mother has a paracentric inversion of chromosome 7. It is suggested that the phenomenon of interchromosomal effect may link these observations. A brief review of the published and computer catalogued data on paracentric inversion in man is included.

Chromosome Inversion↗
PubMed1986

Partial trisomy 7 (q32----qter) syndrome in two children.

Two unrelated children are described with a partial trisomy 7 (q32----qter). Their phenotypes are compared with other reported cases with both this trisomy and others of the 7q arm. Several apparently useful pathognomonic features are distinguished. The phenotypic variability between trisomic persons within and between families is discussed. It is suggested that the disparate monosomies always associated with these trisomies may not make a major contribution to this variability. The importance for genetic counselling of reporting in detail the clinical appearance and development of all children with this rate trisomy is emphasised.

Abnormalities, Multiple↗
PubMed1985

Chromosome damage and sister chromatid exchanges in lymphocyte cultures from patients with two primary cancers.

Sister chromatid exchanges (SCEs) and chromosome damage were scored in lymphocyte cultures from 11 patients with two or more primary cancers and were compared with normal controls. None of the patients had a constitutional chromosome anomaly, but six showed evidence of chromosome instability, which could not be accounted for by treatment, expressed either as elevated SCE frequency or increased nonspecific chromosome damage and chromosome loss. Chromosome damage included major rearrangements as well as deletions and gaps. The possibility of common mechanisms in chromosome instability leading to susceptibility to a heterogeneous group of primary cancers is discussed.

Aged↗
PubMed1984

Triploidy, partial mole and dispermy. An investigation of 12 cases.

Twelve triploid abortuses were investigated to determine the origin of the additional haploid set and were retrospectively examined for the development of partial hydatidiform mole. Eight out of ten suitable triploids were diagnosed as partial mole. Dispermy was indicated as the cause of triploidy in 6 informative cases of which 3 were also partial moles. However, one diandric triploid had no features of partial mole. The problem of maternal cell contamination in triploids and the difficulty of diagnosing partial moles on pathological grounds alone are discussed.

Abortion, Spontaneous↗
PubMed1984

A familial insertion involving an active nucleolar organiser within chromosome 12.

As far as the authors are aware this is the first report of the insertion of an active NOR into a non-acrocentric chromosome, although a simple translocation involving an active NOR has been previously recorded. More specifically, this case involves the non-reciprocal translocation of the centromere and stalk of an acrocentric into 12p, generating an apparently stable dicentric chromosome. The insertion is seen in three generations and may be relatively genetically benign. The abnormality is fully described by G and sequential C banding, DA/DAPI fluorescence, kinetochore staining, and Ag-NOR staining, and the findings are discussed in the light of the limited published reports of insertion in man.

Chromosomes, Human, 6-12 and X↗
PubMed1983

The heterogeneity of the 5q--chromosome marker in refractory anemia.

A patient presenting with an unusual case of refactory anemia is described in whom acquired markers originating from chromosomes No. 5 and 8 are identified by G- and sequential C-banding. Comparison with various published illustrations of chromosome No. 5 deletions in this general broad category of disease raises the possibility that karyotypic misclassification in cases of absent or substandard banding (typical of bone marrow) may help to explain the considerable variation in size and morphology of the 5q--marker.

Adenocarcinoma↗
PubMed1983

De novo translocation heterozygote with three reciprocal translocations.

An extremely rare case of a child with three balanced reciprocal translocations involving six different autosomes is described. These abnormalities have apparently arisen de novo and seem to have only relatively minor phenotypic effects. The meiotic possibilities are discussed and cytogenetic markers suggest that the damage may have occurred in a paternal gamete.

Child↗
PubMed1983

A complex double translocation involving four chromosomes and five breakpoints in a child with mild mental retardation.

A 6-year-old boy with speech delay and mild mental retardation (IQ 82) was found to have a complex double translocation involving four chromosomes and a total of five breakpoints, two being on the same arm. This resulted in the karyotype 46,XY,t(2;4;7)(7;8)(q14;q31;q11q22;q13). As far as the authors are aware this is the first time that such a complex double translocation has been reported. Both parents had normal karyotypes.

Child↗
PubMed1982

An unusual karyotype in preleukemia.

A case of a myeloproliferative disorder classified as preleukemia is described in which the patient developed a single, complicated, abnormal karyotype in 100% of the bone marrow cells (45, XY, -2, -5, -7, -8, -11, -12, -13, -14, + t(2;5), +t(11;12), +t(16;17), +17, plus three or four dicentric markers). The possible significance of these unusual, if not unique, chromosome changes is discussed in relation to hematologic and clinical findings and with particular reference to the existing nonrandom patterns of chromosome changes in myeloproliferative disorders and acute nonlymphoblastic leukemias.

Aged↗