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Biomedical subjects

L Y Hsu

Publications and source records attributed to L Y Hsu.

At least 73 records · Page 4Linked to original sources

Association of 5q- and refractory anemia.

The association of refractory anemia with partial deletion of the long arm of one No. 5 chromosome (5q-) has been reported in six patients within the last two years. We wish to report an additional patient with refractory anemia and an acquired chromosomal deletion, del(5)(q15), in a direct bone-moarrow preparation. The specificity of this deletion for refractory anemia is discussed. It remains to be seen whether patients with refractory anemia and 5q- tend to develop acute leukemia, as has been recently suggested.

Acute Disease↗

Prenatal cytogenetic diagnosis: first 1,000 successful cases.

From February 1969 to August 1976, we studied 1,048 amniotic fluids. Of these, 958 (91.4%) were primarily for prenatal cytogenetic diagnosis. Cytogenetic studies were attempted in 1,021 cases; the diagnosis was successful in 1,000 of these. The failure rate of obtaining a diagnosis from the amniotic fluid cell culture of the first amniocentesis was 5% (50 cases); 29 cases had a repeat tap and successful diagnosis was achieved in all. In 21 cases, a repeat tap was refused. Thus, the overall failure rate of obtaining a final cytogenetic diagnosis was 2.06% (21/1,021). There were 32 fetal losses after amniocentesis including 16 spontaneous second trimester abortions, 7 fetal deaths in utero and 9 stillbirths. In two additional cases, fetal death had occurred before amniocentesis. This number of fetal losses does not exceed the number that would be expected in the same maternal age group without amniocentesis. In our series, the frequencies of trisomy in maternal age groups 40 years and over, 37-39 years, 35-36 years, and under 35 years were 4.5, 3.14, 0 and 0% respectively. These frequencies are comparable to those reported from other prospective prenatal studies and higher than those of retrospective live born studies. Various problems and pitfalls in prenatal cytogenetic diagnosis are discussed.

Adult↗

Trisomy 8 mosaicism syndrome. Report of monozygotic twins.

Monozygotic twins were born with the phenotypical appearance of the trisomy 8 syndrome. The first twin, a stillborn, had autopsy findings suggestive of trisomy 8 syndrome. Cultured lymphocytes and skin fibroblasts of the second, liveborn twin, showed trisomy 8. While the lymphocyte culture showed 46/47, +8 mosaicism, with normal cells predominating, skin fibroblasts yielded only cells with trisomy 8. Bone marrow preparation showed only normal cells, 46,XY. Repeat lymphocyte culture at age 14 months, showed a reduced number of trisomy 8 cells. We would like to emphasize the importance of cytogenetic studies in early infancy, using both peripheral lymphocyte and skin fibroblast cultures, to increase the chance of detecting chromosomal abnormalities.

Abnormalities, Multiple↗

Prenatal diagnosis of 5p-.

With the combination of the various banding techniques (G,Q, and R), a small deletion of the short arm of a No.5 chromosome was detected prenatally in the pregnancy of a 39-year-old woman. The deletion appeared to be either intersitial in nature, involving part of p13 and p14, or the result of a translocation with deletion of p13 leads to pter. Both parents were found to have a normal chromosome constitution with normal banding patterns. Thus, this deletion was a de novo event. Repeat amniotic fluid cell chromosome analysis at the time of elective abortion, and postmortem examination of the fetus confirmed the prenatal cytogenetic diagnosis. We wish to emphasize that precise identification of a small deletion, as in this case, requires a combination of the various banding techniques.

Abortion, Induced↗

Partial trisomy of the long arm of chromosome 1 in myelofibrosis and polycythemia vera.

We have identified partial trisomy 1q in 2 patients with different hematologic disorders. The first patient was a 55-year-old female with myelosclerosis and myeloid metaplasia diagnosed at age 38 years presenting with anemia, fatigue, bruising, fever, and splenomegaly. At age 56, she had 50--95% myeloblast cells and 95--100 nucleated RBC precursors per 100 WBC. Chromosome analysis of unstimulated leukocytes with Q, G, and C banding showed 46,XX,-6,+t(1;6) (q25;p22) in all metaphase cells. In vitro incorporation of Fe55 was demonstrated 90% of metaphases by autoradiography. The second patient, a 49-year-old male, was diagnosed as having polycythemia vera at age 30 during a regular checkup. He since developed hepatosplenomegaly. Chromosome analysis from a direct bone marrow preparation at age 44 and 45 showed grossly normal karyotypes. At age 49, his marrow by Q and G banding showed almost 100% of cells with 46,XY,-13,+t(1;13) (q12;p12). Eleven cases of trisomy of 1q have been reported in various hematologic disorders. It is apparent that partial trisomy 1q represents another nonrandom chromosomal abnormality, in addition to the most common nonrandom chromosomal aberrations, such as the Philadelphia chromosome, trisomy 8, trisomy 9, and monosomy 7 in hematologic disorders.

Chromosomes, Human, 1-3↗

Partial deletion of long arm of chromosome 11: del (11) (q23).

The cytogenetic analysis of an infant with multiple congenital anomalies revealed a small deletion of the long arm of one No. 11 chromosome: 46,XX,del(11)(q23). The main clinical manifestations included: ocular colobomata, absent philtrum, severe congenital heart disease, contractures of the large joints and skin pigmentation. Both parents showed a normal chromosome constitution. In comparison to the previously reported cases of 11q-, the patient presented here had more severe congenital anomalies. The correlation of the size of the deletion, and the location of the break, with the physical findings is discussed.

Abnormalities, Multiple↗

Familial translocation with partial trisomy of 13 and 22: evidence that specific regions of chromosomes 13 and 22 are responsible for the phenotype of each trisomy.

A newborn infant with clinical and pathological findings typical trisomy 13 and 22 syndromes had an extra chromosome which was a derivative chromosome from maternal balanced translocation affecting Nos. 13 and 22; 47,XY,+der(22),t(13:22)(q22:q12)Mat. The presence of extra specific euchromatic regions of No. 13(13q22 and/or 13q34) and No. 22 (22q11) seem to be responsible for the trisomy 13 and 22 syndromes.

Abnormalities, Multiple↗

Supernumerary small ring chromosome.

A supernumerary small ring chromosome was found in 30% of cultured peripheral leucocytes and 50% of skin fibroblasts in a 6-year-old boy with mild mental retardation and midline cleft palate. The extra chromosome appeared to carry a densely staining region on Giemsa banding. The banding patterns of the remaining 46 chromosomes were normal. C banding indicated that the ring chromosome contained mainly centromeric constitutive heterochromatin. Chromosome analysis of both parents showed normal karyotypes by both conventional and banding techniques; thus the origin of the ring chromosome could not be determined.

Child↗

Karyology of primary human fetal cell cultures.

Cell cultures were established from the biopsies of lung, skin and kidney from each of nine human fetuses, and chromosome analyses were performed on material through the fifth subculture. Kidney cell cultures generally showed a higher level of polyploidy than lung or skin. The frequencies of hyperdiploid cells and those with structural abnormalities were consistent with the low levels found in cultures of human lymphocytes. The data provide a normal cytogenetic baseline for human fetal material which may be useful in a variety of studies.

Cells, Cultured↗

Prenatal diagnosis of 45,X/46,XY mosaicism with postnatal confirmation in a phenotypically normal male infant.

Prenatal detection of chromosome mosaicism has always been a diagnostic dilemma. In 21 reported cases of chromosomal mosaicism in cultured amniotic fluid cells, only two cases had cytogenetic confirmation of the mosaicism. All 21 pregnancies resulted in either phenotypically normal liveborns or grossly normal abortuses. We report a case of XO/XY mosaicism detected prenatally and confirmed postnatally in a grossly normal male infant. The indication for prenatal cytogenetic diagnosis was advanced maternal age (38 years). A diagnosis of XO/XY mosaicism was made from two separate culture flasks of amniotic fluid cells, with 45,X cells predominating (86.4%). The Y chromosome was of normal size but carried no fluorescent band. The parents were counseled and were advised that the phenotype of XO/XY mosaicism can range from relative normality to sexual maldevelopment. They decided to continue this pregnancy. The infant was born at term and was a grossly normal male with normal penis and descended, normal-sized testes. Leukocyte culture from the cord blood and a skin fibroblast culture confirmed the mosaicism of XO/XY. The father's Y chromosome was of identical size and carried a small fluorescent band. It appears that an altered Y chromosome may be predisposed to anaphase lag leading to mosaicism.

Amniotic Fluid↗

Three successive prenatal diagnoses of 47,XY,+21.

Within 3 working days in September, 1974, we made three prenatal diagnoses of 47,XY,+21 from three women of advanced maternal age. Two were 37 and 38 years old, respectively, and nulliparous. One was 42 years old and had four normal children. The possibility of cell contamination arose when the second diagnosis of trisomy 21 and a male fetus was made. This suspicion increased when the third case was found within 3 working days. All three cases were then studied with both Q and G banding for identification of individual chromosome markers. Fortunately, the distinction was clear by Q-banding. Each case showed characteristic Q-banding polymorphisms in No. 3 and No. 21 chromosomes. It was evident that these were three separate cases. Problems relating to diagnosis of two or more successive identical trisomies of the same sex can be resolved by banding techniques. The response each family had to learning the diagnosis is presented and discussed.

Age Factors↗