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S A Lynch

Publications and source records attributed to S A Lynch.

At least 37 records · Page 2Linked to original sources
PubMed1999

The accuracy of diagnoses as reported in families with cancer: a retrospective study.

Assessment of risk of developing hereditary cancer and subsequent clinical surveillance is largely based on family history. It is considered standard practice to confirm as many diagnoses as possible in cancer families. Our aim was (1) to assess inaccuracies in reporting of cancers by families, (2) to assess the need for confirmation of diagnosis, and (3) to estimate how many families would have been entered unnecessarily or excluded from screening. A retrospective study of 595 case notes was performed in two centres. Methods of confirmation included information from the cancer registries, death certificates, hospital notes, and histopathological records. Accuracy varied by site of cancer and by the closeness of the relationship to the affected person. Reported abdominal malignancies were inaccurate in 20%, whereas 5% of reported breast cancers were inaccurate. In two families the family history of cancer proved fictitious. Management was altered in 231213 (11%) families following cancer confirmation. The results of the study favour verification of cancer diagnoses particularly if decisions regarding surveillance or prophylactic surgery are based on the family history.

Family Health↗
PubMed1998

A homeobox gene, HLXB9, is the major locus for dominantly inherited sacral agenesis.

Partial absence of the sacrum is a rare congenital defect which also occurs as an autosomal dominant trait; association with anterior meningocoele, presacral teratoma and anorectal abnormalities constitutes the Currarino triad (MIM 176450). Malformation at the caudal end of the developing notochord at approximately Carnegie stage 7 (16 post-ovulatory days), which results in aberrant secondary neurulation, can explain the observed pattern of anomalies. We previously reported linkage to 7q36 markers in two dominantly inherited sacral agenesis families. We now present data refining the initial subchromosomal localization in several additional hereditary sacral agenesis (HSA) families. We excluded several candidate genes before identifying patient-specific mutations in a homeobox gene, HLXB9, which was previously reported to map to 1q41-q42.1 and to be expressed in lymphoid and pancreatic tissues.

Base Sequence↗
PubMed1998

Susceptibility to spina bifida; an association study of five candidate genes.

Clues regarding candidate genes which influence susceptibility to spina bifida and anencephaly come from the identification of folate-associated risk factors and from studies of mouse mutants showing neural tube anomalies. On this basis we selected five candidate genes; CBS, MS, MTHFR, T (Brachyury) and BRCA1 for genetic analysis in 31 Dutch and 48 British NTD families. Ten polymorphisms, two for each gene, were used in transmission tests for disequilibrium (TDT). In six instances more than 50 transmissions from heterozygous parents could be examined. Using TDT we find evidence for an association between an allele at the T gene and liability to NTD in the embryo. Data from British and Dutch populations showed the same trend and in combination gave a chi 2TDT = 4.89, P = 0.03 (OR 2.39, CI 95% 1.02-5.61). No association, in either population group, was found for CBS, MS and MTHFR, the enzymes most directly associated with the known risk factors in folate metabolism. The possibility of complex genetic interactions was explored; the data show that a Gly919 MS variant occurs more frequently in combination with the MTHFR thermolabile variant in mothers of NTD offspring (OR 3.94, CI 95% 1.0-16.3).

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1998

Stickler's syndrome associated with congenital glaucoma.

A case report of Stickler's syndrome associated with congenital glaucoma is presented. Stickler's syndrome is an autosomal dominant disorder characterised by progressive arthropathy, midfacial flattening, Pierre Robin anomaly or cleft palate, sensorineural hearing loss, progressive myopia, vitreoretinal degeneration, and retinal detachment. Congenital glaucoma and Stickler's syndrome are two diagnoses frequently considered in high myopia in infancy. The case report described presents a case of Stickler's syndrome in association with congenital glaucoma. This association is unusual, but important to recognise in the neonatal period. The possibility of coexistence of these clinical entities, should be considered in the future.

Connective Tissue Diseases↗
PubMed1998

Who supports whom? How age and gender affect the perceived quality of support from family and friends.

This study investigates age and gender differences in the relative perception of social support across adulthood. Findings indicate that age and gender do affect both the perception of positive support and the perception of demandingness across different support relationships. In all age groups, men appear to perceive spousal support as the most positive, while women seem to perceive the support received from children as being the most positive. However, it is apparent that all three relationships studied--those with spouse, children, and friends/other relatives--are important sources of support for both men and women.

Adult↗
PubMed1998

Bilateral renal agenesis, cardiac hypertrophy and pancytopenia, a new syndrome?

We report a fetus with an unusual combination of features including bilateral renal agenesis, hydrops, cardiac hypertrophy and pancytopenia. There was haematological evidence of apoptosis with nuclear degeneration of megakaryocytes. The combination of structural anomalies associated with pancytopenia has many features reminiscent of Fanconi's anaemia although Mitomycin C studies were normal. There was no evidence of infection as a cause for the pancytopenia. We suggest that fetal blood sampling should be considered in similar cases with renal agenesis. Some may have a milder form of pancytopenia and may not present with hydrops thereby not prompting further haematological investigation.

Abnormalities, Multiple↗
PubMed1997

Ocular abnormalities in a patient with partial deletion of chromosome 6p. A case report.

We report on a patient with a de-novo deletion of chromosome 6p. This male infant presented with multiple systemic congenital defects together with an unusual ocular phenotype. Slit-lamp examination revealed thin, opaque, rectilinear bands within the anterior segment partially connecting iris to corneal endothelium. These were associated with bilateral hyperopia and optic nerve hypoplasia. Ocular abnormalities in such patients have been documented although the number of individuals is small and identical cytogenetic defects are rarely encountered. We compare the clinical findings in this case with previously described phenotypes. Characterisation of such cases is important as it is becoming apparent that deletion of genetic information encoded on chromosome 6p has implications for ocular embryogenesis.

Abnormalities, Multiple↗
PubMed1997

Sirenomelia, limb reduction defects, cardiovascular malformation, renal agenesis in an infant born to a diabetic mother.

The clinical features of a fetus with sirenomelia, limb reduction defects, cardiovascular malformation and renal agenesis are reported. The mother of the child suffers from insulin dependent diabetes. The limb, cardiac and renal abnormalities are well recognized sequelae of diabetic pregnancies. The association of sirenomelia and maternal diabetes is somewhat controversial. The link between caudal regression syndrome, sirenomelia and maternal diabetes will be discussed.

Cardiovascular System↗
PubMed1996

Genetic mapping of the human homologue (T) of mouse T(Brachyury) and a search for allele association between human T and spina bifida.

We describe a genetic analysis of the human homologue (T) of the mouse T (Brachyury) gene; human T was recently cloned in our laboratory. The protein product of the T gene is a transcription factor crucial in vertebrates for the formation of normal mesoderm. T mutant Brachyury mice die in midgestation with severe defects in posterior mesodermal tissues; heterozygous mice are viable but have posterior axial malformations. In addition to its importance in development, T has intrigued geneticists because of its association with the mouse t-haplotype; this haplotype is a variant form of the t-complex and is characterized by transmission ratio distortion, male sterility and recombination suppression. We have identified a common polymorphism of human T by single strand conformation polymorphism (SSCP) and used this in mapping studies and to re-investigate the idea that human T is involved in susceptibility to the multifactorial, neural tube defect, spina bifida. Our mapping data show that human T maps to 6q27 and lies between two other genes of the t-complex, TCP1 and TCP10. These data add to the evidence that in man the genes of the t-complex are split into two main locations on the short and long arms of chromosome 6. We have used an allele association test which is independent of mode of inheritance and penetrance to analyse data from the spina bifida families. Using this test we find evidence for a significant (p = 0.02) association between transmission of the TIVS7-2 allele of the human T gene and spina bifida.

Alleles↗
PubMed1995

A gene for autosomal dominant sacral agenesis maps to the holoprosencephaly region at 7q36.

Sacral agenesis is a rare disorder of uncertain incidence that has been reported in diverse populations. Although usually sporadic and most commonly associated with maternal diabetes, there is a hereditary form which may occur in isolation or with a presacral mass (anterior meningocele and/or presacral teratoma) and anorectal abnormalities, which constitute the Currarino triad (MIM 176450). The radiological hallmark of hereditary sacral agenesis is a hemi-sacrum (sickle-shaped sacrum) with intact first sacral vertebra. Bowel obstruction is the usual neonatal presentation, but, unlike other neural tube defects, adult presentation is not uncommon. The major pathology is confined to the pelvic cavity and may present as a space-occupying lesion or meningitis due to ascending infection. All recurrences in families have been compatible with autosomal dominant inheritance except for those associated with the isomerism gene at Xq24-q27.1 (ref. 3). Several associated cytogenetic defects have been reported, including 7q deletions. Previous studies failed to detect linkage to HLA markers, but we now present evidence for a location on 7q36. The same region also contains a gene for holoprosencephaly, an early malformation of the extreme rostral end of the neural tube.

Abnormalities, Multiple↗
PubMed1995

Trichothiodystrophy with sideroblastic anaemia and developmental delay.

A patient with sideroblastic anaemia, development delay, and trichothiodystrophy is presented. Trichothiodystrophy is a feature of several autosomal recessive diseases. Photosensitivity, failure to thrive, and developmental delay are commonly observed in affected cases. X linked inheritance accounts for the bulk of cases with sideroblastic anaemia. This case highlights the importance of routine hair microscopy in cases of atypical ectodermal dysplasia.

Anemia, Sideroblastic↗
PubMed1995

Kabuki syndrome-like features in monozygotic twin boys with a pseudodicentric chromosome 13.

We present monozygotic twin boys with features of Kabuki syndrome. The twins were discordant for cleft palate and coarctation of the aorta. The occurrence of Kabuki syndrome in monozygotic twins has not been previously reported and reinforces the belief that this condition has a genetic basis. Chromosomal analysis on the boys showed a pseudodicentric chromosome 13 with an inactive centromere and satellite stalks at 13q12.11: 46,XY,psu dic(13)(13pter-->13q12.11::13p12-->13q11.00:: 13q12.11-->13qter). Their phenotypically normal mother appears to carry the same pseudodicentric chromosome 13.

Abnormalities, Multiple↗