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Biomedical subjects

J W Towner

Publications and source records attributed to J W Towner.

At least 19 recordsLinked to original sources
PubMed1979

Syndromes associated with deletion of the long arm of chromosome 18[del(18q)].

We studied eight persons whose karyotypes demonstrated deletion of a portion of the long arm of chromosome 18. Seven of these persons who showed the typical del(18q) syndrome had a common deletion in band 18q21, most likely band q21.3, and in at least two persons the deletion was interstitial. Another mentally retarded child, dissimilar in appearance, had a more proximal deletion within band 18q12. Two different clinical syndromes resulted from deletions of these different segments of the long arm of chromosome 18.

Abnormalities, Multiple↗
PubMed1978

A fetus with recombinant of chromosome 8 inherited from her carrier father.

A pericentric inversion of chromosome 8, inv(8)(p23q22), in a male carrier resulted in an unbalanced recombinant, rec(8)dup q, inv(8)(p23q22), which was diagnosed prenatally. The features seen in the aborted fetus resembled the features seen in a previously affected child who received the identical recombinant from her carrier mother. In this particular inversion involving chromosome 8, both male and female carriers risk producing an unbalanced progeny. Different familial pericentric inversions are reviewed for the presence or absence of unbalanced recombinants.

Abortion, Spontaneous↗
PubMed1977

Chromosomal anomalies in patients with retinoblastoma.

Karyotypes from 50 persons with retinoblastoma confirmed by histopathological examination were studied by conventional staining and Giemsa-banding techniques. Two chromosomal anomalies were found. An interstitial deletion of the long arm of No. 13 chromosome was identified by Giemsa-banding in the karyotypes from a boy with unilateral retinoblastoma. Another boy with unilateral tumor had a karyotype of 47,XXY. These findings provide additional evidence that a deletion of chromosome No. 13, most likely involving band 13q14, is associated with the development of retinoblastoma. In conjunction with other reports, our findings also suggest that retinoblastoma may be found more frequently in children with chromosomal aneuploidy.

Adolescent↗
PubMed1976

Ring Y chromosome without mosaicism.

A 53-year-old man with a short stocky build, mild mental retardation, gynecomastia and hypogonadism was found to have a small ring Y chromosome unassociated with mosaicism. The ring Y was represented by a minute portion of chromatin or sometimes paired dots which were no larger than the short arm of the normally expected Y. No brightly fluorescent segment of the ring Y was present nor was it observed elsewhere in the karyotype. A primary medical problem was severe osteoarthritis, necessitating bilateral hip arthroplasties. Plasma testosterone was markedly decreased and plasma gonadotropins were increased. Potency was improved following testosterone injections. We conclude that genes responsible for testicular differentiation, maleness and possibly height are located close to the centromere of the Y chromosome, possibly on both the short and long arm. We also conclude that multiple genes are required for a fully developed male phenotype and apparently some of these genes were deleted or not expressed in this patient.

Chromosome Aberrations↗
PubMed1975

Sex chromosome mosaicism of X/XY or X/XY/XYY.

To date, we have studied 7 patients with X/XY mosaicism, one of whom showed an X/XY/XYY pattern. Four patients presented as newly born infants because of incomplete male development, ambiguity of external genitalia or Turner syndrome. The other 3 patients presented in midchildhood or early adult life. Bilateral gonadectomy, histologic examination of the gonads for tumor or testicular tissue, and chromosome analysis from blood and gonad specimens (and usually skin) were done in these 7 patients. The Y cell line and mosaicism were always detected in the blood culture although the predominant cell line in the majority of tissues was 45,X. The Y chromosome in one of the patients failed to show the expected bright fluorescence over the long arm, and the Y chromosome of another patient previously reported had a terminal nonfluorescing portion of the long arm. Patients with masculinization showed normal height and, on laparotomy, mixed gonadal dysgenesis. Patients with Turner syndrome showed bilateral streak gonads (2) and, in one 2 1/2-year-old girl, a bilateral gonadoblastoma. All patients with Turner syndrome were less than the third percentile in height. All 7 patients were reared as female, 4 of them requiring surgery to diminish the size of the clitoris. All 7 patients appeared to be developing normally. Nonrecognition or delay of the diagnosis, which still occurs in this condition, appears to be a result of the mild physical abnormalities in some patients and a clinical diagnosis of Turner syndrome supported only by a negative X-chromatin result.

Adolescent↗
PubMed1975

Familial inversion of chromosome No. 8: an affected child and a carrier fetus.

An infant with multiple congenital anomalies was found to have a duplication-deficiency disorder involving chromosome No. 8. The abnormality was identified as an unbalanced recombinant inherited from the mother who was a carrier of a pericentric inversion of chromosome No. 8. The inversion was observed in several members of this family, including a fetus who was diagnosed by an amniocentesis. The inverted chromosome was demonstrated only with the use of a differential staining technique, in this case, by trypsin-Giemsa banding.

Amniocentesis↗