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Biomedical subjects

G Schwanitz

Publications and source records attributed to G Schwanitz.

At least 19 recordsLinked to original sources
PubMed1992

Chromosomal findings in fetuses with prenatally diagnosed cysts of the choroid plexus.

Choroid plexus cysts were diagnosed in 25 out of 823 fetuses with prenatally diagnosed abnormalities (growth retardation/malformations). Among these, 5 revealed a chromosomal disorder (4 cases with trisomy 18 and one case with a translocation trisomy 21). Additional abnormalities, such as growth retardation, holoprosencephaly, hydrocephalus and club foot, were found in 6 out of the 20 fetuses with no chromosomal abnormality. All fetuses with a chromosomal disorder revealed further typical prenatally recognizable abnormalities. Our observation indicates that prenatally diagnosed choroid plexus cysts should be considered as an indication for prenatal chromosomal diagnosis, although the risk of there being an underlying chromosomal disorder is low in cases with no additional abnormalities.

Abnormalities, Multiple↗
PubMed1990

Prenatal detection of heart defects as an indication for chromosome analysis.

Chromosome investigations were carried out in 588 fetuses with prenatally diagnosed growth retardation and/or congenital malformations. Out of these cases 116 (19.7%) revealed a chromosome disorder. Among the prenatally diagnosed malformations heart defects were detected in 102 fetuses (17.3%) and were therefore one of the most common abnormalities. Within this group of prenatally diagnosed heart defects 41 fetuses (40.2%) had a chromosome disorder, with trisomy 18 and 21 as the most common syndromes. The results of our study demonstrate that heart defects which can be recognized prenatally by ultrasound are caused in about 40% of the cases by a chromosome aberration and that they are therefore always an indication for fetal karyotyping.

Abnormalities, Multiple↗
PubMed1990

Homozygosity of a 6/18 translocation in a hydatidiform mole.

In a complete mole the chromosome investigation revealed a reciprocal translocation 6/18 in a homozygous status. The chromosome polymorphisms of the conceptus could be derived from those of the father. The delineation of the karyotype of the conceptus is discussed. A previous pregnancy of the mother had also led to an abortion of a hydatidiform mole.

Abortion, Spontaneous↗
PubMed1990

[Fetal echocardiography and clinical genetics--a close correlation].

Improving techniques in fetal echocardiography have important implications in the field of clinical genetics. 1) Fetal echocardiography in pregnancies with families with increased recurrence risks for congenital heart disease (CHD): In 473 pregnancies with increased recurrence risks for CHD second-trimester fetal echocardiography was performed. In 11 cases (2.3%) cardiac malformations were present that could be diagnosed in five cases prenatally (hypoplastic left heart, complete atrioventricular canal defect with hypoplastic left ventricle, preductal coarctation of aorta, tetralogy of Fallot, complete atrioventricular canal defect). In six cases the prenatal diagnosis could not be performed (total anomalous pulmonary venous connection [one case], secundum atrial septal defect [two cases], ventricular septal defect [three cases]). The recurrence risk in families with one previously affected child was 1.4% (5/364), and 17.6% (3/17) in families with two previously affected children. In two out of 44 cases with one affected parent a CHD could be diagnosed, in both cases one previous child was already affected. 2) Congenital heart defect as a common symptom in malformation syndromes: CHD is common as a symptom in malformation syndromes. The demonstration of a fetal CHD can lead to diagnosis of a complex malformation syndrome and it is integral in prenatal diagnosis in cases with increased recurrence risks for a complex malformation syndrome. The sonographic diagnosis of a CHD may signal associated chromosomal disorders. Between January 1986 and December 1988 in 433 cases with prenatally diagnosed congenital malformation and/or severe fetal growth retardation a prenatal chromosome analysis was performed. Within this group 77 fetuses demonstrated a CHD and 28 (36%) out of these revealed a chromosomal disorder. The genetic basis of CHD, the most common complex syndromes with CHD, and the principles of genetic counseling in families with CHD are summarized.

Chromosome Aberrations↗
PubMed1989

Rate of chromosomal aberrations in prenatally detected hydrops fetalis and hygroma colli.

Chromosome analyses were carried out in a series of 775 fetuses with morphological abnormalities diagnosed by ultrasound. Among these cases, 57 demonstrated non-immune hydrops fetalis with hygroma colli (group 1) and a further 116 non-immune hydrops fetalis without hygroma colli (group 2). Different chromosome abnormalities were found in 54.5% of cases of group 1 where chromosome analyses could be performed, and in 27.6% of cases of group 2. The most common aberrations were monosomy X and trisomy 21.

Chromosome Aberrations↗
PubMed1989

[Consultation for patients with cheilognathopalatoschisis and their family members. Cooperation between orthodontists and human geneticists].

In children with a cleft lip and palate the question of aetiology always arises. This is the case in particular when the neonatologist discovers or suspects additional malformations. Since newborn children with cleft lip and palate are now usually brought for initial treatment to an orthodontist, it is his responsibility to inform the parents about the possibility and necessity of genetic counselling and possibly, to initiate contact with the appropriate institute. This is always the case when the wish for further children is expressed. If the orthodontist recognizes microsymptoms in the parents or finds indications of their occurrence in the family, he will strongly recommend such a consultation, with cleft lip and palate patients, the orthodontist should discuss a genetic consultation as part of his confidential relationship with the patient so that the young patients understand the possible risk for the next generation. This consultation can bring enormous psychological relief for the patient if there is only a slight risk of recurrence.

Cleft Lip↗
PubMed1989

Duplication 7p de novo and literature review.

We report on a boy with duplication of the short arm of chromosome 7 (karyotype 46,XY, dup (7) (p11.2----pter), QFQ, GTG, RBA). The boy showed delayed closure of fontanels, reduced eyebrows, short nose with low and broad nasal bridge, small upper and prominent full lower lips, severe delay of speech development. Comparison with the phenotype of 15 reported cases from the literature in relation to the extent of the duplicated segment did not show a clear phenotype/karyotype correlation.

Abnormalities, Multiple↗
PubMed1988

Family studies in scleroderma (systemic sclerosis) demonstrating an HLA-linked increased chromosomal breakage rate in cultured lymphocytes.

An increased chromosomal breakage rate (ICBR) was found in 27 of 28 patients with scleroderma (systemic sclerosis, SS) - 5 with the syndrome including calcinosis cutis, Raynaud phenomenon, esophagus hypomotility, sclerodactyly and telangiectasia (CREST), 4 incomplete CREST, 1 overlapping syndrome, 18 progressive systemic sclerosis (PSS). Not only the patients, but also about half of their first-degree relatives showed an increased chromosomal breakage rate (more than 5 breaks per 100 metaphases). This character segregated as a dominant marker in nine families of scleroderma patients. In the six informative of the nine families, the ICBR trait showed close linkage with the HLA region on chromosome 6 (total lod score 5.5 at theta = 0). In these families, ICBR was predominantly observed in linkage with HLA haplotype A1, Cw7, B8, C4AQ0B1, DR3 which is frequently observed in autoimmune diseases. The nature of the agent inducing chromosomal breakage in cultured lymphocytes of some, but not all family members of scleroderma patients remains to be clarified.

Cells, Cultured↗
PubMed1988

Prenatal diagnosis and management in fetuses with cystic hygromata colli.

We report on 45 fetuses with prenatally diagnosed bilateral cystic hygromata colli by ultrasound. Two of the 45 cases involved a twin pregnancy with only one fetus showing hygromata colli. In 2 cases there was only isolated hygromata colli. The other 43 cases showed the signs of non-immune hydrops fetalis. The cytogenetic findings were: 9 fetuses with Turner syndrome, 1 fetus with Turner mosaicism, 1 fetus with trisomy 18, 6 fetuses with trisomy 21, 12 fetuses with normal karyotype, and 16 fetuses with a failed chromosome culture. In fetuses with Turner syndrome and normal karyotype the sonographic findings were similar: massive bilateral hygromata colli, substantial fluid accumulations in skin and body cavities, oligohydramnios and intra-uterine growth retardation. In the cases with trisomy 21, the relative size of the hygromata colli was smaller. Intra-uterine growth retardation and oligohydramnios were not observed. The sole survivor of our group (elective pregnancy interruption: 30 cases; intra-uterine death: 14 cases) (karyotype: 46,XY) presented sonographically with massive ascites, a moderate cystic hygroma, and appropriate fetal development, and a normal amniotic fluid quantity. These findings are analysed in order to provide recommendations for prenatal diagnosis, prenatal management and genetic counselling of the couples concerned.

Adult↗
PubMed1988

[Trisomy 22--prenatal findings in various developmental stages].

Four cases of trisomy 22 in different stages of pregnancy are reported, one of them showing a mosaicism. The diagnosis was made in three of the observations during the first trimenon, in one in the third trimenon. A typical pattern of malformations of developmental retardation could be demonstrated in the embryonic as well as in the extraembryonic tissues. Our findings confirm the different frequency of the single chromosome abnormality in the various stages of development in pregnancy.

Abnormalities, Multiple↗
PubMed1988

Hydrops fetalis as an indication for prenatal chromosome analysis with the example of the diagnosis of a duplication 15q11 and 17q25 due to a familial translocation 15/17.

A child with a combined trisomy 15q11 and 17q25 shows the typical phenotype of partial duplication 17q. The male fetus developed in the 3rd trimenon of pregnancy a nonimmune hydrops fetalis (NIHF). Analysing the chromosomes of 54 cases with NIHF during the 2nd and 3rd trimenon and after birth we found chromosomal abnormalities in 33% of them.

Cells, Cultured↗
PubMed1987

Partial monosomy 22 as result of an X/22 translocation in a newborn with DiGeorge syndrome.

The case of a neonate with clinical symptoms of DiGeorge syndrome is reported. During pregnancy the measurements by ultrasonography revealed already a significant growth retardation of the fetus, for the first time obvious in the 20th week. The child died immediately after birth. A de novo translocation X/22 was observed with the translocation chromosome being late replicating in all mitoses analysed. The own observation is discussed regarding other cases with DiGeorge syndrome and taking the differential diagnoses into account. count.

Adult↗
PubMed1985

On the significance of true trisomy 20 mosaicism in amniotic fluid culture.

Nine new cases of prenatally detected true mosaic trisomy 20 (T20) are reported. In three instances the fetuses were aborted. One fetus showed multiple malformations associated with a high percentage of T20 cells among amniotic fluid (AF) cells and fibroblasts of different fetal tissues. In two other fetuses only a slight facial dysmorphy was seen which was accompanied by a low percentage of T20 cells among AF cells. In five instances the pregnancies were carried to term, and normal somatic and psychomotor development of the children has been observed, in one case up to the age of 24 months. In one case the pregnancy is continuing. The T20 cells were not detected among cultured lymphocytes of these children. A review of the hitherto known cases of prenatally detected mosaic T20 indicates a relationship between the prenatal findings and the fetal development. This may serve as a provisory basis for genetic counselling: in the case of a percentage above 50% of T20 cells among AF cells there seems to be a risk of about 50% for the fetus to be affected by severe anomalies. However, in cases of a prenatally detected mosaic T20 with a percentage equal to or less than 50, fetal or congenital malformations have not been observed among 23 individuals so far examined.

Adult↗