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Biomedical subjects

S Bundey

Publications and source records attributed to S Bundey.

At least 91 records · Page 5Linked to original sources

Calculation of genetic risks in Duchenne muscular dystrophy by geneticists in the United Kingdom.

Pedigrees of Duchenne muscular dystrophy were sent to 32 geneticists in the United Kingdom, asking for their calculations for genetic risks for female relatives. Eighteen participated, of whom only 7 gave correct answers for all pedigrees. The method most used for calculations (the 'Bayesian' method) was most liable to errors in new situations. An alternative, simpler method is presented.

Female↗

Recurrence risks in families of children with symmetrical spasticity.

This study was undertaken to evaluate the recurrence risks for sibs of patients with symmetrical spasticity (either quadriplegia or diplegia) in the absence of factors known to cause spastic cerebral palsy (e.g. pre-term birth, perinatal hypoxia). Among 669 children in the West Midlands with spastic cerebral palsy, 24 had symmetrical spasticity and normal birth histories. This group was clinically and genetically heterogenous. Among their 55 sibs, six had a spastic disorder similar to that in the index patient, and one further sib, who had died young, had been mentally retarded. Of particular interest were two families with an autosomal recessive condition of post-natal microcephaly, myoclonic epilepsy and spastic quadriplegia; and one family, and possibly a sporadic case of X-linked athetoid cerebral palsy. The recurrence risk in this series of approximately 1 in 9 suggests that about half the children with symmetrical spastic cerebral palsy and a normal birth history may have a recessive condition.

Adolescent↗

A clinical and genetic study of chronic proximal spinal muscular atrophy.

A study of chronic proximal spinal muscular atrophy was undertaken with the main aim of obtaining empirical recurrence risks for genetic counselling. Thirty-eight patients and their families were studied. Of these, 33 had similar clinical features and onset of disease in infancy or childhood. A division of these 33 patients by onset before or after 2 years (which was equivalent to whether or not they ever walked normally) gave recurrence risks for sibs which were higher with early onset. Among the sibs of patients with onset before 2 years, the incidence of disease was 1 in 5, due to most patients having an autosomal recessive disorder. A few patients, however, were thought to represent new dominant mutations. Among the families of index patients with onset after 2 years, the incidence of disease in sibs was only 1 in 15, but among their children it as 1 in 8. Both autosomal recessive and autosomal dominant forms therefore occurred in this age group, but it was concluded that nearly half the patients with onset after 2 had non-genetic motor neuron disease. The autosomal recessive form of chronic spinal muscular atrophy generally had onset before 2 years, but occasionally after 2. About a third of the patients never walked, and about half were in wheelchairs by age 10. No genetic heterogeneity within this form was demonstrated. Three remaining patients had distinctive clinical features associated with their proximal weakness, external ophthalmoplegia in one, dysarthria in another, and joint contractures in a third. Only 2 patients had onset in adult life, one of a probable recessive disorder and the other a probable dominant disorder.

Age Factors↗

A genetic study of torsion dystonia.

A family study of 32 patients with torsion dystonia has shown at least two forms of generalized dystonia with onset in childhood. These two forms, an autosomal dominant and an autosomal recessive, are clinically indistinguishable. There were at least three families and probably about six to eight patients with the autosomal recessive variety. The remaining nine to 11 patients with generalized childhood dystonia are thought, because of a probable paternal age effect, to be examples of new dominant mutations. Since fitness with childhood onset is 1/20 of normal, most childhood dominant cases appear sporadically. Most of the other 15 patients (12 with onset in adult life) appear to have a non-genetic torsion dystonia, although an example of a benign adult-onset dominant form associated with a tremor has been observed. It is concluded that there are at least two forms of genetic torsion dystonia, an autosomal recessive form with onset in childhood, which, on evidence from America, is particularly common in Ashkenazi Jews, and one or more dominant forms, with onset in childhood or adult life. The majority of adult-onset isolated cases of idiopathic torsion dystonia seem to be due to exogenous but unidentified causes.

Adolescent↗

Large electroencephalographic responses and their relationship to cleido-cranial dysplasia.

We have reported six individuals (five certain heterozygotes for cleido-cranial-dysostosis and one possible heterozygote) who have unusual EEG findings, consisting of very large responses to photic flash stimulation at very low stimulus rates. Such visual responses are extremely rare and have not been seen before in the experience of an EEG department over 12 years and they were not seen in 98 control subjects. It is likely that these responses are an irregular manifestation of the gene for cleido-cranial-dysplasia, and that the responses are independent of skull deformity. One importance of these responses is their demonstration in neurologically normal individuals for previously such large responses have only been reported in association with neurolipidosis. They may have neurophysiological significance in that they may reflect an unusual balance between inhibitory and excitatory mechanisms in the nervous system.

Adolescent↗

A genetic study of infantile and juvenile myasthenia gravis.

From the present study, and from reports in the literature, two forms of childhood myasthenia emerge. There is an early-onset form (with onset of symptoms under 2 years of age) where the illness is milder but more persistent, and where there is frequent occurrence of myasthenia in sibs. Such cases are likely to be inherited as an autosomal recessive, although it is possible that they represent the extreme edge of a multifactorial distribution of combined genetic and environmental aetiology. The second group (with onset of symptoms between the age of 2 and 20 years) clinically resembles adult myasthenia, which is associated with autoimmunity and an increased incidence of thyroid dysfunction. Some genetic contribution occurs in this form but it is less marked than with the early-onset cases and there is no recognizable pattern of inheritance. As secondary cases are even less common among the families of adult myasthenics, it is likely that individuals with most genetic predisposition to myasthenia tend to develop symptoms early, and that non-genetic factors are relatively more important for the development of myasthenia in adults.

Adolescent↗