Biomedical subjects

T C Cahill

Publications and source records attributed to T C Cahill.

3 recordsLinked to original sources

PubMed1992

Second-trimester echogenic bowel and chromosomal abnormalities.

OBJECTIVE: Our objective was to examine the outcomes of pregnancies in which echogenic bowel was detected in the second trimester. STUDY DESIGN: Twenty-two cases with a prospective diagnosis of echogenic bowel were reviewed. Karyotypic studies were performed in 19 cases, and 17 families had deoxyribonucleic acid-based risk assessment for cystic fibrosis. The echogenicity of the bowel was retrospectively reviewed and graded as mild or bright. RESULTS: Five cases of trisomy 21 and one case of trisomy 18 were detected; four of these had other ultrasonographic abnormalities. Twenty-seven percent of fetuses with echogenic bowel were aneuploid. Risk was greatest for cases with brightly echogenic bowel. No cystic fibrosis mutations were detected. The diagnosis of echogenic bowel was reproducible. CONCLUSION: Brightly echogenic bowel in the second trimester was found to be associated with a significant risk of fetal aneuploidy.

Chromosome Aberrations↗

PubMed1991

Biochemical and genetic analysis of a child with cystic fibrosis and cystinosis.

We have studied a child with cystic fibrosis (CF), nephropathic cystinosis, and manifestations of Bartter syndrome, a finding reported previously in both of these diseases (CF and cystinosis). The chance of an individual inheriting a mutant allele for both CF and cystinosis from each of his parents by independent segregation is very small. Therefore, other mechanisms of inheritance were investigated, including whether his diseases were caused by a chromosome deletion or rearrangement that caused defects in both genes, whether his phenotype was caused by a new mutation or variant of either disease, or whether both diseases were inherited together due to inheritance of 2 copies of the same chromosome from one of the parents (uniparental disomy). An investigation was made of whether having mutations for both CF and cystinosis resulted in a different phenotype for either disease and whether the child was a heterozygote rather than a homozygote for one of the mutations. The results suggest that neither disease influenced the expression of the defect in the other and that this child inherited a mutant allele for both diseases independently from each parent.

Cysteine↗

PubMed1990

Resolution of DNA linkage discrepancies through analysis of a VNTR locus in a family study of cystic fibrosis.

First-trimester prenatal diagnosis of a fetus at 25 per cent risk for cystic fibrosis (CF) was performed by indirect linkage analysis of polymorphic markers using Southern blotting and polymerase chain reaction (PCR) amplification. The results revealed discrepancies in the allelic patterns between the father and the affected child, thereby complicating the prediction of fetal outcome. Analysis of a highly polymorphic VNTR locus within the human retinoblastoma (RB) gene on chromosome 13 showed that the affected child and the fetus did not have the same biological father, and therefore the affected child could not be used to determine linkage of markers in the father of the fetus. The analysis of VNTR loci can be an effective method of resolving conflicting data during prenatal diagnosis of monogenic diseases.

Adult↗