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Biomedical subjects

W R Breg

Publications and source records attributed to W R Breg.

At least 19 recordsLinked to original sources
PubMed1991

Familial occurrence of esophageal atresia with and without tracheoesophagel fistula: report of two unusual kindreds.

We describe 2 unique kindreds with familial occurrence of esophageal atresia (EA) with or without tracheoesophageal fistula (TEF) and reviewed the literature on familial EA +/- TEF. EA +/- TEF appears to be causally heterogeneous with evidence pointing to the existence of non-genetic developmental and multifactorial forms. The literature suggests that the parents of a single affected child should be given an empiric recurrent risk between 1/2 and 2%, rising to 20% if more than one sib is affected. The empiric risk of an affected child born to an affected parent is 3-4%. Empiric risk figures are useful in counseling families at the present time; however, the 2 kindreds presented here raise the possibility of autosomal dominant transmission in certain families. A third generation of affected offspring, or additional family reports should help to clarify this issue in the future.

Adult↗
PubMed1991

"Pseudomosaicism" for 4p- in amniotic fluid cell culture proven to be true mosaicism after birth.

Pseudomosaicism is noted in approximately 1% of amniotic fluid cell studies. Some represent numerical abnormalities, but pseudomosaicism for structural chromosomal abnormalities is also seen. Pseudomosaicism is not usually considered clinically significant. Recently, we evaluated a 13-month-old girl with developmental delay and minor anomalies suggestive of 4p- syndrome. In 5 of 100 peripheral lymphocytes, she had a deletion 46,XX,del(4)(p15). Review of a prenatal amniocentesis study performed on the mother of our patient disclosed that one colony of 18 examined from 2 in situ cultures had the same abnormality, whereas none of the 27 cells from a flask culture showed the abnormality. Results of this study had originally been reported as showing pseudomosaicism. To our knowledge, amniotic fluid pseudomosaicism of a structural abnormality has not previously been shown to reflect true mosaicism in fetal tissue or liveborn children. The actual incidence of this phenomenon is unknown, but it may be present in unexamined children with minimal clinical findings. Apparently only one previous case of mosaic 4p- in a liveborn individual has been reported.

Amniocentesis↗
PubMed1991

Diagnosis of Angelman syndrome in infants.

The diagnosis of Angelman syndrome (AS) has seldom been made in infants because the previously described characteristic manifestations usually are not apparent until after age 2 years. We describe 4 AS patients, one of whom has oculocutaneous albinism, who were less than 2 years old when first evaluated. All 4 have deletions of the region q11.2-q13 of chromosome 15. In the 3 cases in which parents were available for study the deleted chromosome 15 was maternally derived, as determined by cytological markers. All of the patients presented with severe to profound global developmental delay and postnatal-onset microcephaly; they had seizures, hypotonia, hyperreflexia, and hyperkinesis. All were hypopigmented as compared to their relatives. Each had eye abnormalities; all had choroidal pigment hypoplasia. None were initially described as having an abnormal appearance. We believe that AS is far more common than previously thought and present these 4 children to emphasize the manifestations that may be helpful in making the diagnosis in the young patient. We also emphasize the hypopigmentation that patients with AS frequently have, including what we think is the first reported case of albinism and AS.

Chromosome Deletion↗
PubMed1990

Duplication of euchromatin without phenotypic effects: a variant of chromosome 16.

A family with an unusual variant of chromosome 16 is presented. The mother and son both with additional material present in the short arm of chromosome 16 adjacent to the centromere are phenotypically normal. The extra C-band negative region has been shown not to be composed of alpha satellite DNA. The literature regarding other familial cases of what appears to be the same variant of chromosome 16 is reviewed.

Adult↗
PubMed1988

Report of two cases of distal deletion of the long arm of chromosome 6.

We report on two patients with distal deletions of 6q. In one case a de novo translocation between chromosomes 6 and 7 resulted in del(6q25----6qter). The other case had a de novo deletion, also from 6q25 to 6qter. There have been eight previous reports of distal deletions of 6q. These patients have developmental retardation, microcephaly, craniofacial anomalies, various types of congenital heart defects, and anomalies of hands and feet. The facial similarities of our two patients and those in six published photographs are subtle and may represent an emerging phenotype.

Abnormalities, Multiple↗
PubMed1987

A comparison of language characteristics of mentally retarded adults with fragile X syndrome and those with nonspecific mental retardation and autism.

Fragile X syndrome is a recently identified form of mental retardation that is associated with a chromosomal abnormality and inherited in an X-linked manner. Previous studies have suggested that distinctive speech and language characteristics are associated with the syndrome. Twelve adult male residents of an institution for the retarded (aged 23 to 51 years) were compared on a series of speech and language measures to 12 adult males with nonspecific forms of MR who were residents of the same institution and were matched on age and IQ. A second contrast group consisted of similarly matched autistic men. Results revealed that there were no significant differences among the groups' performance, with the exception of increased rates of echolalia in the autistic group. A nonsignificant trend toward poorer performance on expressive measures on the part of the fragile X group was noted. The implications of these findings for further research on the syndrome are discussed.

Adult↗
PubMed1986

Trisomy 22 mosaicism syndrome and Ullrich-Turner stigmata.

Mosaic trisomy 22, ascertained in three unrelated patients, was found to be associated with body asymmetry and signs of the Ullrich-Turner syndrome including short stature, ptosis, webbed neck, nevi, cubitus valgus, dysplastic nails, malformed great vessels, and abnormal ovaries. These anomalies in trisomy 22 mosaicism have not been emphasized heretofore. In each of our patients, trisomy 22 mosaicism was found only in fibroblasts. In one patient, the trisomy resulted from a paternal first meiotic nondisjunction, and in the 46,XX cells, both chromosomes 22 were of paternal origin.

Adult↗
PubMed1986

Chromosome deletion 1q42-43.

We report on a newborn male and a female of 3 years 9 months with de novo 1q42 or 43-qter deletions. These cases are compared with ten other reported cases.

Child, Preschool↗
PubMed1986

Regional location of alpha 1-antichymotrypsin and alpha 1-antitrypsin genes on human chromosome 14.

The human protease inhibitor genes alpha 1 antitrypsin (alpha 1-PI) and alpha 1-antichymotrypsin (alpha 1-ACT) are acute-phase proteins which are induced in response to inflammation. These inhibitors function to limit the activity of serine proteases in vivo. alpha 1-PI acts as an inhibitor of neutrophil elastase to protect the elastin fibers of the lung. Genetic deficiencies of alpha 1-PI result in development of chronic pulmonary emphysema. The physiologic role of alpha 1-ACT has not been clearly defined, but it also appears to function in the maintenance of protease-protease inhibitor equilibrium in the lung. Nucleic acid and protein sequence homologies detected between alpha 1-PI and alpha 1-ACT suggested an evolutionary relationship. Gene mapping experiments were performed to determine if these protease inhibitor genes reside at the same chromosomal locus in man. In situ hybridization data demonstrate that both alpha 1-PI and alpha 1-ACT map to the same region, q31-q32.3, on chromosome 14.

Cell Line↗
PubMed1984

Cytogenetic diagnosis using midtrimester fetal blood samples: application to suspected mosaicism and other diagnostic problems.

Cytogenetic studies on fetal blood cells obtained at 18-25 weeks gestation have provided information for decision making in 25 cases identified as being at high risk of having an abnormal fetus. In particular, in the 21 cases studied to consider the possibility of true mosaicism, confirmation in fetal blood was obtained in three, one of which presented as a pseudomosaic on the original amniotic fluid cell study. Fetal blood was also informative in two cases (one positive and the other negative) in which a diagnosis of the fragile X syndrome was being considered. Furthermore, when high risk pregnancies presented late in gestation (21-24 weeks), these methods allowed for a rapid cytogenetic diagnosis. The procedure has proved useful in most of these cases since the couples involved had indicated that they would probably have terminated the pregnancy without the reassurance of normal fetal lymphocyte studies. Since the technique carries a much higher risk of pregnancy loss than does amniocentesis, its use should only be considered when there are compelling indications.

Cells, Cultured↗
PubMed1984

Evidence for the clonal origin of acquired hypomegakaryocytic thrombocytopenic purpura from a sex chromosome mosaic.

Cytogenetic studies performed on a 79-year-old female presenting with clinical and hematologic features of acquired hypomegakaryocytic thrombocytopenic purpura revealed sex chromosome mosaicism in blood lymphocytes (45,X/46,XX/47,XXX). The presence of only 45,X cells in the bone marrow is consistent with a unicellular origin of acquired hypomegakaryocytic thrombocytopenia in this patient. These studies also suggest that, in some instances, this disorder may originate at the level of the pluripotent hematopoietic stem cell.

Aged↗
PubMed1984

Human c-fos oncogene mapped within chromosomal region 14q21----q31.

The human cellular homolog (c-fos) of the transforming gene of Finkel-Biskis-Jinkins (FBJ) murine osteosarcoma virus was mapped to a single human chromosome. DNA from a series of 31 mouse-human somatic cell hybrid lines was probed with v- and c-fos molecular clones by Southern blotting. Human c-fos segregated with the distal region of the long arm of human chromosome 14. In situ hybridization of 125I-labeled human c-fos probe to normal human metaphase chromosomes independently confirmed these results and localized the c-fos oncogene to region 14q21----q31.

Animals↗
PubMed1984

A method of processing first-trimester chorionic villous biopsies for cytogenetic analysis.

Chorionic villous biopsy is emerging as a technique for obtaining fetal cells for prenatal diagnosis in the first trimester of pregnancy. Chromosome analysis has been performed on small villous biopsies using either direct harvests of uncultured cells or after culturing villous tissue. Here, we describe a method where both techniques can be used simultaneously; from a single villous biopsy, GTG-banded chromosomes of improved morphology are obtained from direct preparations and from cultured villous cells.

Biopsy, Needle↗
PubMed1981

Homogeneously staining region in a retinoblastoma cell line: relevance to tumor initiation and progression.

A human retinoblastoma cell line was found to contain a homogeneously staining region (HSR) on chromosome 1 (at 1p34). An HSR had previously been identified at the same site in a human neuroblastoma cell line. Of the original retinoblastoma line, a subpopulation was found which did not contain the 1pHSR but did contain a 3p+ chromosome in which the additional segment resembled a small HSR. The 3p+ was most likely the result of the translocation between the 1pHSR and the short arm of a chromosome 3. Preliminary results also indicate that the retinoblastoma cells with the 1pHSR produced tumors in athymic nu/nu mice in an average of 28 days, while identical numbers of the retinoblastoma cells with the 3p+ (probable HSR) produced tumors in an average of 75 days.

Cell Line↗