Biomedical subjects

S M Kleyman

Publications and source records attributed to S M Kleyman.

22 records · Page 2Linked to original sources

PubMed1996

A de novo interstitial deletion of chromosome 15 band q25 as revealed by FISH-technique.

We report a new chromosomal finding in a 20 month-old girl. The minor clinical features included: moderate mental retardation, microcephaly, mild hypotonia and hypertelorism. Initially, what appeared to be a terminal deletion of the long arm of one chromosome 15 [15q26-->qter] was determined to be an interstitial deletion involving band 15q25 as revealed by FISH-technique, showing the presence of intact telomeric hybridization signals. The cytogenetic diagnosis was thus modified to 46,XX, del (15) (pter-->q24::q26--> qter). Nevertheless, the function of the enzyme telomerase should not be ignored, as healing could occur following such terminal deletions. Consequently, it will remain a difficult task to distinguish terminal deletions from those that are interstitial.

Chromosome Banding↗

PubMed1996

Centromeric alphoid sequences are breakage prone resulting in pericentromeric inversion heteromorphism of qh region of chromosome 1.

Structural variations in the pericentromeric region of chromosome 1 are considered the norm. We characterized a chromosome 1 with an inversion by FISH-technique and suggested that the origin of pericentromeric heteromorphism is far more complex than previously suggested. It is postulated that similar to the centromeric alphoid DNA sequences of chromosome 9, chromosome 1 also possesses a "breakage prone" centromeric domain which may be a possible cause of such inversions involving the secondary constriction region.

Adult↗

PubMed1996

Incidence of breakpoints in pericentric inversions of chromosome 4.

We report a new pericentric inversion of chromosome 4 in a female who has had two consecutive fetal losses during the first trimester conception. Cytogenetic findings with GTG-banding revealed a 46,XX,inv(4) (p13q13) karyotype in her peripheral blood cells. The breakpoint on the long arm is different from any other previously described case. A comprehensive bibliography of reported cases with pericentric inversion is also tabulated.

Chromosome Breakage↗

PubMed1996

Characterization of a de novo t(Y;9) (q11.2;q22) by FISH technique.

A new case with a de novo translocation involving the long arms of chromosomes Y and 9 i.e. 46, X, t(Y;9) (q11.2;q22) was noted in a phenotypically normal male as revealed by GTG technique and subsequently confirmed using dual color whole chromosome painting probes. Since the Yq11.2 region was involved in the translocation the fecundity status of the individual has been questioned. Previous cases with (Y;autosomal) translocations have produced males with azoospermia, a variety of male gamete deformities and idiopathic sterility. The azoospermic factor (AZF) on the distal Yq11 band, which apparently controls spermatogenesis, may have been adversely affected due to a microdeletion, rearrangement or complete loss as a result of the translocation mechanism. Testicular histological and fertility tests of the proband at a postpubescent age will reveal the status. The sex determining region (SRY) on the Yp, which has been equated with the testis determining factor (TDF), is believed to be intact. Dual color whole chromosome painting probes, which served as an important adjunct to GTG banding, increased the degree of certainty for the characterization of the involved translocation. A concise review of balanced (Y ; autosome) translocation cases are annotated here.

Chromosomes, Human, Pair 9↗