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Biomedical subjects

R M Winter

Publications and source records attributed to R M Winter.

At least 181 records · Page 10Linked to original sources

Epiphyseal dysplasia of the femoral head, mild vertebral abnormality, myopia, and sensorineural deafness: report of a pedigree with autosomal dominant inheritance.

A family is presented with short stature, femoral epiphyseal dysplasia, mild vertebral changes, and sensorineural deafness inherited as an autosomal dominant trait. Myopia and retinal detachment presenting in adult life were also present in some affected members. We suggest that this disorder may be a distinct entity within the spondyloepiphyseal dysplasia group of disorders.

Abnormalities, Multiple↗

Fetal valproate syndrome: is there a recognisable phenotype?

Four infants who were exposed to sodium valproate or valproic acid during pregnancy are described. Common facial features in the three surviving infants include epicanthic folds, a flat nasal bridge, a broad nasal base, anteverted nostrils, a shallow philtrum, and a thin upper lip with a thick lower lip. Ridging of the metopic suture, congenital heart defect, postaxial polydactyly, and hypospadias were additional features in individual cases. In agreement with previous authors, we feel that there is a distinctive 'fetal valproate' phenotype.

Abnormalities, Drug-Induced↗

A previously undescribed syndrome of thoracic dysplasia and communicating hydrocephalus in two sibs, one diagnosed prenatally by ultrasound.

We describe two opposite sexed sibs, the offspring of consanguineous Pakistani parents, with a previously undescribed syndrome. The main features are short ribs with a narrow chest and thoracic dysplasia, mild shortening of the limbs, communicating hydrocephalus, and developmental delay. One sib was diagnosed prenatally by ultrasound at 18 weeks' gestation. The inheritance of the condition is presumed to be autosomal recessive.

Consanguinity↗

Analysis of linkage relationships between genetic markers around the fragile X locus with special reference to the daughters of normal transmitting males.

Genetic linkage data from loci around the fragile X locus at Xq27.3 are analysed in the light of the hypothesis of Pembrey et al. (1985) concerning the generation of the fragile X mutation. Recombination between the four loci 52A, F9, fragile X, and ST14 is significantly decreased in meioses giving rise to the affected grandsons of normal transmitting males, when compared to families where there are no apparent normal transmitting males. There are at least two possible explanations for this phenomenon. Either the established fragile site at Xq27.3 promotes increased recombination in the distal part of the X chromosome as a secondary event, unrelated to the mechanism of formation of the fragile site itself, or an event involving recombination at or around Xq27.3 is the mechanism of formation of the full fragile X mutation, and the decreased recombination seen amongst flanking marker loci in meioses giving rise to the affected grandsons of normal transmitting males is the result of interference.

Chromosome Mapping↗

Gene localisation of X-linked hypohidrotic ectodermal dysplasia (C-S-T syndrome).

Genetic linkage studies were carried out in families with X-linked hypohidrotic ectodermal dysplasia (C-S-T syndrome). A DNA probe DXYS1 (pDP34), which maps both to the proximal part of the long arm of the X chromosome, Xq13-Xq21, and proximally on Yp, was used to detect a TaqI restriction fragment length polymorphism of the X-chromosomal locus in the DNA samples from 11 families. This locus was found to be closely linked to the X-linked hypohidrotic ectodermal dysplasia locus, with a lod score of 2.66 at recombination fraction (theta) of 0.06 (90% confidence limits 0.01-0.26). Only one crossover was observed in nineteen meioses. This indicates that the probe DXYS1 is closely linked to the X-linked hypohidrotic ectodermal dysplasia locus and is likely to facilitate carrier detection and prenatal diagnosis tests.

Alleles↗

A case of Fryns syndrome.

A case of Fryns syndrome is presented. Characteristic features of this lethal autosomal recessive disorder include corneal clouding, camptodactyly with hypoplastic nails, and abnormalities of the diaphragm.

Abnormalities, Multiple↗

A male infant with the Catel-Manzke syndrome and dislocatable knees.

A male infant is described with severe micrognathia and bilateral duplication of the proximal phalanges of the index fingers, an association which is characteristic of the Catel-Manzke syndrome. In addition, he had dislocatable knees, which have not been described in this disorder before.

Fingers↗

Robinow syndrome without mesomelic 'brachymelia': a report of five cases.

A family is described in which the father and his two children had Robinow syndrome, but with no consistent brachymelia or dwarfism. Two further sporadic cases are described, one with rhizomelic brachymelia and dwarfism and the other with generalised shortening of the limbs. An attempt is also made to distinguish between the phenotype of autosomal dominant and recessive cases on the basis of the familial cases in this paper and other reported cases.

Abnormalities, Multiple↗

First trimester prenatal diagnosis and detection of carriers of haemophilia A using the linked DNA probe DX13.

Although the use of a gene specific deoxyribonucleic acid (DNA) probe is the method of choice for detecting carriers of genes for rare genetic disorders, there will always be families in which such probes cannot be used because key subjects are not informative for restriction fragment length polymorphisms in or around the gene. In these cases closely linked DNA markers have to be used. An X chromosome specific DNA probe, DX13, which is closely linked to the haemophilia A locus on the X chromosome, was used for early prenatal diagnosis in two cases and to detect carriers in a series of nine possible heterozygote women. The first reported crossover between DX13 and the factor VIII:C locus was observed in this study. There are complexities inherent in using any linked DNA probe for assignment of genes, but such techniques are clinically important.

Female↗

A premutation that generates a defect at crossing over explains the inheritance of fragile X mental retardation.

The view that the Martin-Bell syndrome (X-linked mental retardation with fragile site at Xq27/8) is inherited in a regular X-linked fashion is becoming untenable with the increasing number of reports of transmission through phenotypically normal males. Analysis of the published pedigrees containing such males shows that their heterozygous daughters are never mentally retarded, and have either no fragile site or very few indeed. By contrast, in the next generation, a third of the female heterozygotes are mentally subnormal with an average of 29% fragile sites. These data suggest a premutation that generates the definitive mutation only when transmitted by a female. We propose an inherited sub-microscopic chromosome rearrangement involving the Xq27/8 region that causes no ill effect per se, but generates a significant genetic imbalance when involved in a recombination event with the other X chromosome. This hypothesis explains many of the puzzling genetic aspects of the Martin-Bell syndrome, but it also complicates the interpretation of linkage analysis with genetic markers.

Crossing Over, Genetic↗

Type 1 (insulin-dependent) diabetes and a highly variable locus close to the insulin gene on chromosome 11.

A polymorphic DNA sequence in the 5'-flanking region of the human insulin gene was studied in relation to Type 1 (insulin-dependent) diabetes. In 141 Caucasoid subjects analysed by Southern blot hybridisation techniques, two major DNA insertions were observed: a Class 1 allele or a Class 3 allele. The Class 2 allele was not observed in this group of subjects. Genotype frequencies in a control population (n = 88) were: homozygous 1/1, 42%; heterozygous 1/3, 50%; and homozygous 3/3, 8%. Corresponding genotype frequencies in 53 Type 1 diabetic patients were 79%, 21% and 0%, respectively (p less than 0.0005 from chi 2 test). This confirms prevalence data reported by Bell et al. [16]. There appeared to be no coinheritance with HLA-DR3/DR4 related antigens, nor with autoimmune features. Analysis of 17 Type 1 diabetic pedigrees including 34 diabetic and 69 non-diabetic subjects did not demonstrate genetic linkage of these DNA inserts with diabetes, using an autosomal recessive, single locus model of inheritance.

Alleles↗