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Biomedical subjects

T Kajii

Publications and source records attributed to T Kajii.

At least 127 records · Page 7Linked to original sources
PubMed1981

13S+. Giant satellites or de novo rearrangement?

A seven-year-old Japanese girl with mental retardation, epileptic seizures controllable by anticonvulsants, short stature, and multiple minor malformations was found to have apparent giant satellites on chromosome No.13. The karyotypes of her parents and elder brother were normal. Banding studies revealed that the apparent giant satellites consist of four G-bands, and are thus a de novo rearrangement product. The origin of the aberrant No. 13 was traced to a paternal meiotic error, using Q-banding and silver staining heteromorphisms as markers. Thus, the patient represents an unbalanced, de novo chromosomal rearrangement masquerading as giant satellites, with the origin of the extra chromosomal material unknown, a hitherto undescribed situation.

Abnormalities, Multiple↗
PubMed1981

Kabuki make-up syndrome: a syndrome of mental retardation, unusual facies, large and protruding ears, and postnatal growth deficiency.

A previously unrecognized mental retardation malformation syndrome was observed in five unrelated Japanese children. Consistent clinical features included moderate-to-severe mental retardation, progressive dwarfism of postnatal onset, a peculiar facies characterized by long palpebral fissures, with eversion of the lateral third of the lower eyelids, arched eyebrows, broad and depressed nasal tip, large prominent earlobes, short fifth fingers, abnormal dermatoglyphics including absence of digital triradius c or d, and frequent otitis media in infancy. Inconsistent abnormalities included epicanthal folds, cleft or high-arched palate, widely spaced teeth, low occipital hair line, scoliosis, and dislocation of the hip joint. Neither familial occurrence nor parental consanguinity was noted. The etiology of the malformation syndrome remains unknown.

Abnormalities, Multiple↗
PubMed1981

Monozygotic twins discordant for rubinstein-taybi syndrome.

A pair of male monozygotic twins discordant for Rubinstein-Taybi syndrome is reported. Monozygosity of the twins was established using blood grouping, typing of serum proteins, isozymes, HLA, and chromosomal heteromorphisms. The twins are the first twin pair discordant for the syndrome in which monozygosity has been firmly established. The pathogenesis of the syndrome is discussed in relation to the occurrence of both discordant and concordant monozygotic twins.

Abnormalities, Multiple↗
PubMed1980

13q-/r(13) mosaicism.

A 2-month-old female infant with typical features of the 13q-syndrome was found to be a hitherto unreported mosaic consisting of 46,XX,del(13)(q22)-46,XX,r(13)(p13q22). Both of the 13q- and r(13) chromosomes were Ag N banding positive. Therefore, it was assumed that they had retained the satellite stalks. Two possible mechanisms were proposed for the genesis of the mosaicism. Firstly, the patients started with the 13q- chromosome, which then underwent breakage and reunion at both ends to form the r(13) chromosome. Secondly, the patients started with the r(13) chromosome, which reopened at or close to the joining point to form the 13q- chromosome.

Abnormalities, Multiple↗
PubMed1979

Inverse maternal age effect in monosomy X.

The maternal age distribution of 45,X abortuses was significantly lower than that of chromosomally normal abortuses in two co-ordinated studies. One, carried out in Geneva, included 44 X-monosomic abortuses and the other, in Hiroshima, was based on 38 abortuses with a 45,X karyotype. It was deduced that 45,X conceptuses result from either non-disjunction during paternal meiosis or anaphase lag during meiosis or mitosis, and that anaphase lag is more frequent among young couples than among older ones.

Abortion, Spontaneous↗
PubMed1978

Anatomic and chromosomal anomalies in 944 induced abortuses.

A total of 944 induced abortuses, 922 of which apparently were anatomically normal and 22 of which were anatomically abnormal, were set up in culture. Of these abortuses, 910 (96.4%) were successfully karyotyped. The study can be divided into two periods. In the initial period, specimens without recovered fetal tissues were excluded, and no chromosome anomalies were found among the 182 abortuses karyotyped. In the later period of study, abortion specimens both with and without recovered fetal tissues were included, and 23 chromosomally abnormal abortuses, 9 of which were without recovered fetal tissues, were found among the 728 abortuses karyotyped. This gives a chromosome abnormality rate of 3.2%. The mean ovulation age for the 728 abortuses was 63.4 days (range 33--109 days). The mean maternal age was 28.4 years (range 15--48 years). The chromosomally abnormal abortuses included 13 (10 nonmosaic and 3 mosaic) trisomics, 7 triploids, 2 abortuses with balanced D/D translocations and an abortus with an XXq- karyotype. Among the 616 abortuses in which both amniotic and fetal tissues were karyotyped, there was complete karyotypic agreement between the two tissues. Among the 339 abortuses in which tissue samples from both sides of the body were analyzed, complete agreement was also found. Factors that may influence the prevalence of abnormal karyotypes in induced abortuses are discussed.

Abortion, Induced↗
PubMed1978

Familial occurrence of a syndrome with mental retardation, nasal hypoplasia, peripheral dysostosis, and blue eyes in Japanese siblings.

Two Japanese siblings, a 2-year-old girl and a 7-month-old boy, had a syndrome of mental retardation, severe nasal hyp9plasia, peripheral dysostosis, and blue eyes. The mother showed nasal hyp9plasia of lesser degree and a mild form of peripheral dysostosis. This disorder bears a striking similarity to acrodysostosis, but in view of certain novel features its relationship to the disease is uncertain. The mode of inheritance could be either dominant with variable expressivity or autosomal recessive.

Bone Diseases, Developmental↗
PubMed1978

Successive spontaneous abortions including one with whole-arm translocation between chromosomes 2.

A family with five induced and seven spontaneous abortions and no live births is described. Four of the seven spontaneous abortuses were available for cytogenetic examination and three were successfully karyotyped. Their karyotypes were 46,XX; 46,XX/46,XX,t(2;2)(2p2p;2q2q); and 46,XY. The karyotypes of the parents were normal. The origin of the 2p/2p and 2q/2q translocation in one of the abortuses was assigned to an interhomologous whole-arm translocation in an early mitotic division in a conceptus with a 46,XX karyotype.

Abortion, Habitual↗
PubMed1977

Origin of acrocentric trisomies in spontaneous abortuses.

A total of 33 spontaneous abortuses with various acrocentric trisomies were studied for the origin of the extra chromosomes using Q- and R-band polymorphisms as markers. Eleven trisomic abortuses were informative: nine trisomic abortuses (one with trisomy 13, three with trisomy 21, and five with trisomy 22 including one with a 46,XX/47,XX,+22 mosaicism) originated at maternal first meiosis; a 21-trisomic abortus resulted from an error at maternal second meiosis (or first mitosis); and a 13-trisomic abortus was of maternal first or second meiotic origin. The abortus with mosaic trisomy 22 started as a 22-trisomic zygote resulting from an error at maternal first meiosis, followed by a mitotic (in vivo or in vitro) loss of the paternally derived chromosome 22.

Abortion, Spontaneous↗
PubMed1977

Origin of triploidy and tetraploidy in man: 11 cases with chromosomes markers.

Sixteen triploid and one tetraploid human abortuses were studied for the origin of polyploidy using a sequential Q- and R-banding technique. Ten triploid abortuses provided informative data: one originated in the maternal first meiotic division; five apparently resulted from dispermy; two derived from an error during either the paternal second meiotic division or the first mitotic division; and the last two were of paternal origin. The results indicate that paternal factors, especially dispermy, are the predominant sources of triploidy in man. The tetraploid abortus showed duplication of both the maternal and paternal haploid sets, suggesting normal division of chromosomes and suppression of cytoplasmic cleavage at the first mitotic division. No correlation was found between the origin of polyploidy and the phenotype of the triploid abortuses, nor between the origin of polyploidy and the maternal use of oral contraceptives.

Abortion, Spontaneous↗
PubMed1975

Sequential Q- and Acridine orange-marker technique.

A standardized Q- and acridine orange (AO)-fluorescence dual marker technique was described. It involved preservation of unstained chromosome slides in a vacuum desiccator up to 18 months, Q-staining, destaining, and treatment in Hanks' solution, pH 5.1, at 85 degrees C for 13 min, and acridine orange staining. Q-markers were found at the paracentromeric regions of chromosomes 3 and 4, the short arms and the satellites of the acrocentric chromosomes, while AO-marker spots were on the satellite-stalks of the acrocentrics. The advantage of the dual marker technique was illustrated by the determination of the origin of trisomy 22 in a spontaneous abortus.

Abortion, Spontaneous↗