Search PubMed⌕ Search

Biomedical subjects

K Kucheria

Publications and source records attributed to K Kucheria.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Study of sex determination gene (SRY) in 46,XY gonadal dysgenesis].

During mammalian embryogenesis, the presence of the SRY gene determines the bipotential gonad to develop as a testis. 46,XY sex reversal has been described in man. It is associated with an essentially female phenotype and a streak gonad. In a collaborative study, we analysed 36 patients with a 46,XY sex reversal. The testis determining region of the Y chromosome was analysed by Southern blotting and by DGGE analysis of the SRY open reading frame (orf). We found a total of 7 mutations in the testis determining region including the SRY gene. This brings to 19 the total number of mutations in SRY associated with sex reversal. No relationship was found between the SRY status and the presence or absence of gonadoblastoma. However, a correlation was observed between the SRY genotype and the histology of the gonad. A mutant in SRY is associated with a completely dysgenetic gonad. The presence of immature testicular tubules is usually observed when SRY is normal. These latter results suggest the existence of as yet unidentified testis determining genes.

DNA-Binding Proteins↗
PubMed1992

XY sex reversal associated with a deletion 5' to the SRY "HMG box" in the testis-determining region.

The human testis-determining factor resides within a 35-kilobase (kb) region of the Y chromosome immediately adjacent to the pseudoautosomal boundary. A candidate gene for human sex determination (SRY) was isolated in this region. Here, we describe a study of 25 cases of XY females with pure gonadal dysgenesis for mutations on the Y chromosome short arm, including SRY. Southern blotting revealed a sex-reversed female harboring a deletion extending from approximately 8 kb from the pseudoautosomal boundary of the Y chromosome to at least 33 kb and no more than 60 kb upstream, toward the centromere. The deletion begins no more than 1.8 kb upstream from the first ATG of the SRY open reading frame present in the clone pY53.3. To our knowledge, no mutation has been described previously outside the SRY "HMG box" on the short arm of the Y chromosome, which is associated with sex reversal. Since the 5' extent of the SRY transcriptional unit has not been defined, the deletion may remove upstream exons of SRY and/or transcriptional regulatory motifs, either situation resulting in lack of testicular development. It cannot be formally excluded that the mutation removes a second locus, independent of SRY, that is critical for sex determination. Denaturant gradient gel electrophoresis analysis of the SRY open reading frame in the remaining 24 cases revealed de novo single base-pair transitions in the SRY conserved domain in 4 cases.

Amino Acid Sequence↗
PubMed1992

Sister-chromatid exchanges are increased in epileptics, but not by sodium valproate.

Sister-chromatid exchange (SCE) frequency has been studied from peripheral blood lymphocyte cultures of 21 patients with epilepsy on sodium valproate, 20 patients who had not started therapy (untreated) and 20 normal healthy controls. Treated and untreated patients with epilepsy were observed to have higher SCE frequencies (mean 9.05 and 9.82 respectively) than healthy controls (mean 4.8; P < 0.001). There was no significant difference in SCE frequency between treated and untreated patients. This suggests that the disease itself may be associated with an increased frequency of SCEs.

Adolescent↗
PubMed1992

A transsexual male with 47,XYY karyotype.

Transsexuals are usually found to have a normal chromosome complement. The literature to date documents four transsexuals with 47,XYY pattern. This paper reports a fertile male with major cell line of 47,XYY and a gender identity disorder.

Adult↗
PubMed1992

Induction of sister chromatid exchanges in phenytoin treated & untreated patients with epilepsy.

The mutagenic potential of phenytoin (PHT) was studied using the sister chromatid exchange (SCE) assay. Twenty nine PHT treated epileptics, 32 untreated and 32 normal healthy controls were analysed. Similar SCE frequencies were observed in untreated patients and patients on PHT monotherapy. Both groups had significantly increased SCE frequency as compared to controls. No positive correlation of SCE frequency with sex and duration of therapy was observed. The results of the present study suggest the role of the disease condition in inducing genetic damage as assessed by increased SCE frequencies.

Adolescent↗
PubMed1990

Primary amenorrhoea in a triple X female.

The incidence of trisomy X in the newborn population is estimated to be 1 in 1,000 liveborn females. Most of them have normal physical appearance and puberty. Therefore, the reported number of triple X females in the literature is low. We herein report one patient with triple X chromosomes, primary amenorrhoea and normal intelligence. Steroid hormonal levels, clinical and ultrasound findings were suggestive of ovarian failure/gonadal dysgenesis. This case emphasizes the need for chromosomal analysis in women presenting with premature ovarian failure leading to primary or secondary amenorrhoea.

Adult↗
PubMed1981

An Indian family with postaxial polydactyly in four generations.

An Indian family was observed with postaxial polycactyly in four generations. Of the twelve affected cases, eleven were male and one was female. The affected males showed postaxial polydactyly Type A in both hands and feet. The affected female showed polysyndactyly and both Types A and B postaxial polydactyly. Study of this family strongly suggests a common causal factor for postaxial polydactyly Types A and B and polysyndactyly. The observations also support an autosomal dominant pattern of inheritance and a high degree of genetic heterogeneity in ths malformation.

Abnormalities, Multiple↗