PubMed Health⌕ Search

Biomedical subjects

D S Krishna Murthy

Publications and source records attributed to D S Krishna Murthy.

16 recordsLinked to original sources
PubMed1995

Recurrent regular trisomy-21 in two Bedouin families. Parental mosaicism versus genetic predisposition.

Two young, unrelated multiplex families with Bedouin ancestors, each confirmed to have 3 sibs with recurrent regular trisomy-21 are reported. Low grade mosaicism for trisomy-21 (3/350 cells) was confirmed in the mother in one of the families but not in the other. However, two of the relatives (first degree) were confirmed to have Down syndrome. The recurrence risk for trisomy-21 based on livebirth and prenatal diagnosis data were estimated at 1 to 2 percent for couples 35 years old or younger at the time of conception. However, such risk estimates are not available for recurrence of simple trisomy-21 to a particular couple (<35 years). Clustering of trisomy-21, trisomy-18 has been reported among Bedouins. The possibility of cryptic parental mosaicism as well as < > should be considered in genetic counselling of families with sibships of regular trisomy-21 or other aneuploidy.

Arabs↗
PubMed1993

Disease profile of 400 institutionalized mentally retarded patients in Kuwait.

In this preliminary report we summarize the results of a 4-year multidisciplinary systematic, etiological clinicogenetic survey of 400 institutionalized mentally retarded patients in Kuwait. All had an intelligence quotient below 50. A constitutional disorder, as the direct cause of the mental retardation, was found in 203 patients (50.75%)): a chromosomal abnormality in 37 (9.25%), Mendelian disorders in 137 (34.25%), MCA/MR in 22 (5.55%) and CNS malformations in 7 cases (1.75%). In 157 patients (39.35%) a pre-, peri or postnatal cause was ascertained. No etiological diagnosis was detected in 40 patients (10%). A detailed analysis of the "disease profile" is given and compared with the results of previous diagnostic genetic surveys among different institutionalized mentally retarded populations in Western and developing countries.

Abnormalities, Multiple↗
PubMed1993

Familial pericentric inversion of chromosome 13, 46,XX,inv (13)(p13;q11): a new variant.

A 10-year-old female with right oblique inguinal hernia was investigated to exclude an XY karyotype. Chromosome analysis of peripheral blood showed 46,XX,inv(13)(p13;q11). In vitro aneuploidy was observed in two cells: a) 46,XX,inv(13), inv(13); b) 47,XX, +inv(13). Her father and three sisters were carriers for inv(13). Herein the authors review briefly familial inv(13)'s and report a new variant involving breakpoints (p13;q11).

Child↗
PubMed1990

Mosaicism 45,X/46,X, t dic(Xp:Xp) in a girl with short stature.

An eight-year-old girl with marked short stature and no apparent stigmata of Turner syndrome was investigated. Clinical features include bilateral epicanthic folds, frontal bossing, prominent ears and normal intelligence. Ultrasound scanning revealed an apparently normal vagina, streak ovaries and no uterus. Bone age was normal. Karyotype analysis of peripheral blood lymphocytes showed mos 45,X/46,X tdic(Xp:Xp) in the ratio 66:34, respectively. In addition, three cells with different abnormal X chromosomes were present which possibly originated from a 46,XX clone. Replication of the duplicated X chromosome was consistently late and symmetrical. Buccal smear confirmation of the karyotype showed Barr body negative in 90% and large or bipartite in 10% of the cells. Karyotypes of the parents were normal. The clinical manifestations in cases of Xp deletion due to terminal rearrangement associated with or without a 45,X cell line are discussed.

Body Height↗
PubMed1989

Inherited pericentric inversion of Y-chromosome with trisomy 21. A case report.

A 13-year-old boy with clinical features of Down syndrome was investigated. His karyotype was 47,X,inv(Y),+21. The proband's father and two elder brothers were also found to have the inv(Y). A spontaneous chromatid break was observed in the long arm of the X chromosome[? fra (X)] in 2% of the cells. The mother had two spontaneous abortions. This is the first case of trisomy-21 with inv(Y) in our population. This finding might be fortuitous. The frequency of inv(Y) in Down syndrome is not known.

Chromosome Inversion↗
PubMed1987

Robertsonian translocation t dic (14p;22p) with regular trisomy 21: a possible interchromosomal effect?

Robertsonian translocations occur in about 2.5% of Down syndrome. We report here a Down syndrome with karyotype, 46,XX,-14,-22,+der t dic(14p;22p)pat, +21. Proband's father, two sisters, and a brother are phenotypically normal, heterozygous carriers for dicentric t(14;22). This is the only case of a translocation t(14;22) with regular trisomy 21 in our series of 600 Down syndrome cases investigated. The prevalence of balanced Robertsonian translocations in parents of Down syndrome might be higher if all the parents of trisomy 21 individuals were routinely investigated. The case is of interest in understanding the possibility of interchromosomal effect in the etiology of non-disjunction in Down syndrome.

Child, Preschool↗
PubMed1986

Klinefelter's syndrome, mosaic 46,XX/46,XY/47,XXY/48,XXXY/48,XXYY: a case report.

A 35-year-old male was investigated for primary infertility. Clinical examination showed an intelligent man with normal facial appearance and moustache and small firm testes. Testicular histopathology revealed marked atrophy of the testes with no spermatogenesis and absence of germ cells. Hormonal profile showed elevated levels of FSH,LH and low levels of testosterone. Chromosome analysis from whole blood culture showed cells with 46,XX/46,XY/47,XXY/48,XXXY/48,XXYY mosaicism. The predominant cell line was 47,XXY (87.86%). 46,XY/47,XXY mosaicism is not uncommon. However, mosaicism of multiple sex chromosome aneuploidy is rarely observed. This is the first report of mosaicism in Klinefelter's syndrome variant with five cell lines.

Adult↗