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Biomedical subjects

J Burn

Publications and source records attributed to J Burn.

At least 127 records · Page 7Linked to original sources
PubMed1993

Congenital heart disease in CHARGE association.

This study reviews the spectrum of congenital heart disease and associated anomalies in 59 patients with the CHARGE association. We have analyzed our clinical experience in managing the cardiovascular anomalies and have reviewed outcome and risk factors for mortality. This study also highlights problems of cardiac management in children born with multiple system involvement. Twenty patients have died; actuarial survival was 78% at 1 year and 60% at 10 years. In only four of the nonsurvivors could their demise be ascribed to their underlying congenital heart disease. We found the outlook for survival was poor if more than one of the following three features were present; cyanotic cardiac lesions, bilateral posterior choanal atresia, or tracheoesophageal fistula. However, mortality was largely due not to the structural heart or choanal abnormalities, but instead reflected the underlying pharyngeal and laryngeal incoordination which resulted in aspiration of secretions. Furthermore, outcome is likely to be improved if collaboration between specialist surgical teams allows necessary procedures to be performed using the minimum of anesthetics. Examination of both the short- and long-term management of these children has stressed the importance of a multidisciplinary approach to their care. The pattern of cardiac defects was not random; lesions within the Fallot spectrum accounted for 33% of their congenital heart disease. Atrioventricular septal defects were also overrepresented. Not all cardiovascular defects could be explained by hypothesizing a neural crest etiology.

Abnormalities, Multiple↗
PubMed1993

Isolation of a gene expressed during early embryogenesis from the region of 22q11 commonly deleted in DiGeorge syndrome.

DiGeorge syndrome (DGS) is one of several syndromes associated with deletions within the proximal long-arm of chromosome 22. The region of chromosome 22q11 responsible for the haploinsufficiency syndromes (the DiGeorge Critical Region or DGCR) has been mapped using RFLPs, quantitative Southern blotting and FISH. Similar deletions are seen in the velo-cardio-facial syndrome (VCFS) and familial congenital heart defects. It is not known whether the phenotypic spectrum is the result of the hemizygosity of one gene or whether it is a consequence of contiguous genes being deleted. However, the majority of patients have a large (> = 2Mb deletion). In this paper we report the isolation of a gene, lab name T10, encoding a serine/threonine rich protein of unknown function which maps to the commonly deleted region of chromosome 22q11. Studies in the mouse indicate that it maps to MMU16 and is expressed during early embryogenesis. Although not mapping within the shortest region of overlap for DGS/VCFS, and therefore not the major gene involved in DGS, the expression pattern suggests that this gene may be involved in modifying the haploinsufficient phenotype of hemizygous patients.

Amino Acid Sequence↗
PubMed1993

Germline rearrangement of MCC and APC detected by pulsed field gel electrophoresis and fluorescent in situ hybridization.

Pulsed field gel electrophoresis was carried out on lymphocyte DNA obtained from ten patients with the inherited premalignant condition adenomatous polyposis coli and a similar number of control samples to search for large scale molecular rearrangements in the vicinity of the APC locus. DNA from one patient showed a rearranged pattern which was interpreted as evidence for an inversion of approximately 150 kb, changing the transcriptional orientation of the neighbouring MCC gene and bringing it closer to APC. Such an interpretation was supported by fluorescent in situ hybridization data.

Adenomatous Polyposis Coli↗
PubMed1993

An association between migrainous aura and hereditary haemorrhagic telangiectasia.

Hereditary haemorrhagic telangiectasia (HHT) is a rare autosomal dominant disorder characterized by a variety of abnormalities of the vasculature. This study investigated by questionnaire an unselected group of 58 patients suffering from HHT to identify and diagnose any headache history. These were compared with a control group comprising 40 patients with an unrelated autosomal dominant disorder, familial adenomatous polyposis. Fifty percent of the HHT patients reported attacks of headache which fulfilled current diagnostic criteria for migraine with aura. This was over four times the figure for the control group and at least 10 times the expected level for a normal population. The auras described by all the affected patients were classic visual disturbances preceding the headaches. Two patients also described typical visual auras unassociated with headache symptoms. The reason for such a clear association between migraine with aura and HHT is uncertain but cerebral arteriovenous malformations seem to be the likely link. A greater understanding of the reasons for the relationship may provide an insight into the pathophysiology of both conditions.

Adult↗
PubMed1993

Colonic fermentation of complex carbohydrates in patients with familial adenomatous polyposis.

Decreased production of butyric acid by colonic carbohydrate fermentation may predispose to colonic carcinogenesis, with the implicit assumption that the decrease in faecal butyrate found predates the development of the tumour. The influence of the genetic predisposition to colonic tumours and the presence of colonic polyps on in vitro fermentation of carbohydrates was examined. Stool samples from 11 normal controls and 20 patients with familial adenomatous polyposis (FAP) were incubated anaerobically with a range of carbohydrates. Fermentation patterns were similar for glucose and raffinose. These sugars produced different short chain fatty acid (SCFA) patterns from the two polysaccharides, starch and arabinogalactan, which differed one from the other. The FAP gene carriers with polyps produced less butyrate than normal controls (p < 0.005) and gene carriers without polyps (p < 0.05). There were corresponding decreases in the molar ratios of butyrate. Gene carriers without polyps produced less absolute amounts of acetate than normal controls (p < 0.05) and slightly less total SCFAs (p < 0.05) but were otherwise not significantly different. The decreased production of butyrate noted by other workers may be secondary to the tumours rather than a contributory cause.

Adenomatous Polyposis Coli↗
PubMed1993

Isolation of a new marker and conserved sequences close to the DiGeorge syndrome marker HP500 (D22S134).

End fragment cloning from a YAC at the D22S134 locus allowed the isolation of a new probe HD7k. This marker detects hemizygosity in two patients previously shown to be dizygous for D22S134. This positions the distal deletion breakpoint in these patients to the sequences within the YAC, and confirms that HD7k is proximal to D22S134. In a search for coding sequences within the region commonly deleted in DGS we have identified a conserved sequence at D22S134. Although no cDNAs have yet been isolated, genomic sequencing shows a short open reading frame with weak similarity to collagen proteins.

Amino Acid Sequence↗
PubMed1993

Conotruncal anomaly face syndrome is associated with a deletion within chromosome 22q11.

The conotruncal anomaly face syndrome was described in a Japanese publication in 1976 and comprises dysmorphic facial appearance and outflow tract defects of the heart. The authors subsequently noted similarities to Shprintzen syndrome and DiGeorge syndrome. Chromosome analysis in five cases did not show a deletion at high resolution, but fluorescent in situ hybridisation using probe DO832 showed a deletion within chromosome 22q11 in all cases.

Abnormalities, Multiple↗
PubMed1993

DiGeorge syndrome: part of CATCH 22.

DiGeorge syndrome (DGS) comprises thymic hypoplasia, hypocalcaemia, outflow tract defects of the heart, and dysmorphic facies. It results in almost all cases from a deletion within chromosome 22q11. We report the clinical findings in 44 cases. We propose that DiGeorge syndrome should be seen as the severe end of the clinical spectrum embraced by the acronym CATCH 22 syndrome; Cardiac defects, Abnormal facies, Thymic hypoplasia, Cleft palate, and Hypocalcaemia resulting from 22q11 deletions.

Abnormalities, Multiple↗
PubMed1993

A large, dominant pedigree of atrioventricular septal defect (AVSD): exclusion from the Down syndrome critical region on chromosome 21.

We describe a large pedigree of individuals with autosomal dominant atrioventricular septal defect (AVSD). The pedigree includes affected individuals and individuals who have transmitted the defect but are not clinically affected. AVSDs are a rare congenital heart malformation that occurs as only 2.8% of isolated cardiac lesions. They are the predominant heart defect in children with Down syndrome, making chromosome 21 a candidate for genes involved in atrioventricular septal development. We have carried out a linkage study in the pedigree by using 10 simple-sequence polymorphisms from chromosome 21. Multipoint linkage analysis gives lod scores of less than -2 for the region of trisomy 21 associated with heart defects, which excludes a locus within this region as the cause of the defect in this family.

Adult↗
PubMed1993

Cornelia de Lange syndrome--photo essay.

Cornelia de Lange syndrome is a rare developmental malformation syndrome characterized by developmental delay, retardation of growth, limb reduction abnormalities and dysmorphic facial features. With the exception of one case with a de novo translocation (Ireland et al., 1991) there are no consistent chromosomal abnormalities or biochemical markers. Diagnosis is therefore dependent on the recognition of the distinctive facial features. In this photo essay we focus on those features which are most specific to the syndrome and highlight possible diagnostic pitfalls.

Adolescent↗
PubMed1993

Agnathia-holoprosencephaly: a new recessive syndrome?

The association between agnathia and holoprosencephaly is well documented (Pauli et al., 1981). Pauli et al. described two female sibs with agnathia and holoprosencephaly who were subsequently shown to carry an unbalanced 46,XX, der 18,t(6;18)(pter p24.1) karyotype (Pauli et al., 1983; Krassikoff and Sekhon, 1989). All other cases have been sporadic (Cohen, 1989). We present a recurrence of agnathia-holoprosencephaly in an unrelated European couple and postulate that this association may represent an autosomal recessive syndrome.

Abnormalities, Multiple↗
PubMed1992

Atrial fibrillation and stroke: prevalence in different types of stroke and influence on early and long term prognosis (Oxfordshire community stroke project)

OBJECTIVE: To determine in patients with first ever stroke whether atrial fibrillation influences clinical features, the need to perform computed tomography, and prognosis. DESIGN: Observational cohort study with maximum follow up of 6.5 years. SETTING: Primary care, based on 10 general practices in urban and rural Oxfordshire. SUBJECTS: Consecutive series of 675 patients with first ever stroke registered in the Oxfordshire community stroke project. MAIN OUTCOME MEASURES: Prevalence of atrial fibrillation by type of stroke; effect of atrial fibrillation on case fatality rate and risk of recurrent stroke, vascular death, and death from all causes. RESULTS: Prevalence of atrial fibrillation was 17% (95% confidence interval 14% to 20%) for all stroke types (115/675), 18% (15% to 21%) for cerebral infarction (97/545), 11% (4% to 11%) for primary intercerebral haemorrhage (7/66), and 0% (0 to 11%) for subarachnoid haemorrhage (0/33). For patients with cerebral infarction the 30 day case fatality rate was significantly higher with atrial fibrillation (23%) than with sinus rhythm (8%); the risk of early recurrent stroke (within 30 days) was 1% with atrial fibrillation and 4% with sinus rhythm. In patients who survived at least 30 days the average annual risk of recurrent stroke was 8.2% (5.9% to 10.9%) with sinus rhythm and 11% (6.0% to 17.3%) with atrial fibrillation. CONCLUSIONS: After a first stroke atrial fibrillation was not associated with a definite excess risk of recurrent stroke, either within 30 days or within the first few years. Survivors with and without atrial fibrillation had a clinically important absolute risk of further serious vascular events.

Aged↗
PubMed1992

Deletions within chromosome 22q11 in familial congenital heart disease.

Because a locus on chromosome 22q11 is deleted in most individuals with DiGeorge and Shprintzen syndromes--conditions in which heart abnormalities are an important feature--we have looked for deletions in nine families with recurrent outflow-tract heart defects. In five families, chromosome 22 deletions were detected in all the living affected individuals studied and also in the clinically normal father of three affected children. The deletion was transmitted from parents to offspring and was associated with an increase in the severity of cardiac defects. No deletions were found in four families in which the parents were normal and affected siblings had anatomically identical defects. We propose that deletions within band q11 of chromosome 22 are an important cause of familial heart defects.

Autoradiography↗
PubMed1992

Velo-cardio-facial syndrome associated with chromosome 22 deletions encompassing the DiGeorge locus.

The large clinical overlap between DiGeorge syndrome and velo-cardio-facial syndrome suggests an aetiological connection. DiGeorge syndrome is associated with microdeletions of chromosome 22q11 and is therefore likely to be caused by reduced dosage of genes within this region. We present preliminary data that velocardiofacial syndrome patients have similar chromosome deletions, a finding consistent with the hypothesis that these disorders represent part of a spectrum of abnormalities seen with monosomy for 22q11.

Abnormalities, Multiple↗