PubMed Health⌕ Search

Biomedical subjects

D S Borgaonkar

Publications and source records attributed to D S Borgaonkar.

At least 37 records · Page 2Linked to original sources

Segregation analysis in reciprocal translocation carriers.

Segregation analysis of the offspring of balanced translocation carriers was performed on 327 pedigrees collated from published sources and personal communications. Correction was made for bias of ascertainment. Translocations studied involved chromosome arms 1p, 4q, 6p, 6q, 7p, 8p, 10p, 10q, 11q, 14q, 16q, and 17p. Findings included similar rates of occurrence of abnormal liveborn offspring in male and female carriers except for a reduction of risk in male carriers of translocations segregating by 3:1 mode; an elevated risk of fetal loss (spontaneous abortions and stillbirths) in female carriers of 6q, 11q, and 16q translocations compared to male carriers of these translocations; a fetal loss rate exceeding general population estimates in female carriers of 6q and 10q translocations and in male carriers of 6p, 8p, 10q, and 14q translocations including a rate of nearly 50% among female 6q translocation carriers; a higher than expected number of balanced carriers among liveborn offspring; and a low risk of abnormal liveborn children among carriers ascertained by means other than through unbalanced probands. We propose that some translocation carriers may be helped by consideration of more specific empiric risk figures than have traditionally been used.

Abortion, Spontaneous↗

Sister chromatid exchanges in the peripheral blood of cigarette smokers and in lung cancer patients; and the effect of chemotherapy.

Peripheral blood sister chromatid exchange (SCE) rates in chronic cigarette smokers and in subjects with cancer do not differ from those in healthy nonsmokers. SCE patterns were normal in 69 chronic cigarette smokers, including 62 patients with untreated lung cancer. In three chronic smokers with lung cancer, high SCE levels were related to recent intravenous chemotherapy.

Aged↗

Atlantoaxial malformation in a 46,XY, 17q+ child.

A child with 46,XY, 17q+ chromosome aberration and unusual skeletal abnormalities had the presenting symptom of respiratory arrest after a fall and minor head trauma. He exhibited proportionate short stature, peculiar facies with antimongoloid slant, simian creases, postaxial hexadactyly, metatarsus adductus deformity, and anomalous penoscrotal configuration. Delayed speech and mild mental retardation were also present. Atlantoaxial dislocation secondary to odontoid process hypoplasia was demonstrated. Additional skeletal abnormalities included dysplastic changes in the first and fourth metacarpals, the middle phalanx of the second finger, and hypoplasia of the first metatarsal, with medial insertion of the great toe. Treatment consisted of halo jacket cast and fusion of the occiput to C1, C2, and C3. Early detection and preventive surgery for atlantoaxial dislocation is necessary to prevent neurological deficit and possibly death by respiratory failure.

Axis, Cervical Vertebra↗

Break points in human chromosomes.

Break points of structural rearrangements of human chromosomes can be identified by banding techniques. The present study attempts to analyze the randomness and the distribution of the reported spontaneous break points in the human genome. Reports of break points in structural rearrangements of human chromosomes from the published sources up to October 1976 were analyzed. Based on the assumption that each unit length of band has an equal chance of being broken, chi2 tests show that positions of breakage are highly non-random; that is, breaks are more frequent in the negative band areas and in the centromeric and terminal regions. In double-break rearrangements the same band types tend to rejoin. The distribution of breaks is not proportional to the chromosome length. The longer chromosomes (i.e., 1--12, X) have a lower number of breaks per unit length, while the shorter chromosomes (i.e., 13--22, Y) have a greater number of breaks per unit length with the exception of chromosomes 4, 9, 10, 16, 17, 19, 20 and X. Out of the whole genome, chromosomes 9, 13, 18, 21, 22 and Y have the most breaks per unit length and chromosomes 16, 6, 2, 3 and 19 have the fewest. 18p11, 21q22 and Yp11 are the three bands with most frequent breaks. There are 53 bands where no breaks have been reported.

Chromosome Aberrations↗