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Biomedical subjects

D L Viljoen

Publications and source records attributed to D L Viljoen.

At least 19 recordsLinked to original sources
PubMed1992

Putative monosomy 21 in two patients: clinical findings and investigation using fluorescence in situ hybridization.

Complete monosomy 21 is claimed to be a rare chromosomal disorder in which the cytogenetic investigation is bedevilled by technical difficulties. We describe the disparate clinical features in two patients in whom an initial diagnosis of monosomy 21 was made by routine karyotyping. Fluorescence in situ hybridisation (FISH) confirmed a translocation of chromosome 21 material to the short arm of chromosome 5 and to the X chromosome, respectively. The usefulness of FISH in the investigation of subtle chromosomal rearrangements is hereby demonstrated. These findings also cast doubt on the existence of "pure" monosomy 21 as an entity, and suggest that partial monosomy 21 is a more likely occurrence.

Abnormalities, Multiple↗
PubMed1991

Founder effect in 20 Afrikaner kindreds with pseudoxanthoma elasticum.

The pedigrees of 20 families with pseudoxanthoma elasticum (PXE) were investigated. The analyses involved 13 generations up to and including the initial settlers, who arrived in the Cape before 1660. Four settler surnames predominate in these pedigrees. Because of the marriage patterns of the settlers' descendants it was necessary to classify the four surnames into two groups. It is suggested that these two groups are the founder groups of present-day PXE patients. Similar genealogical studies have been performed on kindreds with familial polyposis, familial heart block and familial hypercholesterolaemia, among other disorders. Due to geographical isolation, political developments and cultural factors in the Afrikaner, these investigations are feasible and often lead to the identification of founder origin.

Female↗
PubMed1991

Prenatal diagnosis in autosomal dominant Beckwith-Wiedemann syndrome.

A 20-year-old woman with Beckwith-Wiedemann syndrome (BWS) was ultrasonographically appraised at intervals during her pregnancy. Unequivocal evidence for a diagnosis of BWS was obtained in the fetus and this was confirmed postnatally. Early ultrasound diagnosis enabled appropriate genetic counselling to be given; neonatal complications, such as hypoglycaemic episodes, were prevented.

Adult↗
PubMed1991

An apparently new mental retardation syndrome in three elderly sisters.

Three elderly sisters with profound mental retardation in association with the clinical features of microcephaly, short stature, brachydactyly type D, flattened occiput, down-slanting palpebral fissures, low-set large ears, broad prominent nose and kyphoscoliosis have been investigated. Each was more than 60 years of age and their clinical features were strikingly similar. The disorder has several manifestations in common with Rubenstein-Taybi syndrome and appears to be inherited as an autosomal recessive in this family.

Abnormalities, Multiple↗
PubMed1991

Deletion of chromosome 13 in Moebius syndrome.

A girl aged 2 1/2 years with Moebius syndrome was found to have a deletion of band q12.2 in chromosome 13 (46,XX,del(13)(q12.2]. This is the second report concerning involvement of chromosome 13q and Moebius syndrome. The observation raises the possibility that a gene responsible for Moebius syndrome is located in this region of chromosome 13.

Child, Preschool↗
PubMed1991

Microcephaly-cardiomyopathy: a new autosomal recessive phenotype?

A distinctive phenotype of severe microcephaly and self-limiting dilated cardiomyopathy has been observed in two sibs suggesting autosomal recessive inheritance. Mental retardation, delayed developmental milestones, and minor dysmorphism were additional features.

Abnormalities, Multiple↗
PubMed1990

Mirror polydactyly: pathogenesis based on a morphogen gradient theory.

We report on an infant with 7 toes of the left foot in a mirror configuration in association with ipsilateral duplication of the calcaneus and fibula, tibial aplasia, femoral hypoplasia, and a teratomatous sacrococcygeal tumour. The possible pathogenetic mechanisms leading to this limb abnormality are discussed with special emphasis on a field morphogen gradient hypothesis.

Female↗
PubMed1990

Plastic surgery in pseudoxanthoma elasticum: experience in nine patients.

Nine women between the ages of 22 and 56 years underwent cosmetic surgery for correction of the severe cutaneous stigmata of pseudoxanthoma elasticum (PXE). The outcome was generally favorable, and follow-up for up to 15 years showed only moderate regression of the skin manifestations. No serious intraoperative or postoperative complications occurred, although tissue friability, poor wound healing, and keloid formation were noted in a minority of persons. An unexpected problem of extrusion of calcium particles through the surgical wound occurred in two individuals. This resulted in delayed healing and unsightly scars.

Adult↗
PubMed1989

Handicapping and genetic disorders in Zimbabwean institutions: a diagnostic survey.

A diagnostic survey was undertaken in twelve Zimbabwean institutions for deaf, crippled and mentally handicapped individuals. A total of 1396 persons were evaluated of whom 885 were deaf, 356 physically disabled and 155 were mentally retarded. Acquired causes formed the largest aetiological group throughout the survey, but a high frequency of inherited crippling disorders was encountered (125 individuals). Down Syndrome accounted for almost one third of children with mental handicap. Undifferentiated autosomal recessive deafness was found in 87 persons, most of whom were from the Shona people.

Deafness↗
PubMed1988

Childhood deafness in Zimbabwe.

An investigation involving 885 children in five institutions for the deaf in Zimbabwe was conducted with a view to determining the cause of hearing loss. The cause of deafness in 40% of cases was an infectious or infective disorder, while in 43% the basic defect was unknown. There was a seemingly high prevalence of autosomal recessively inherited undifferentiated deafness among children from the Shona tribe. Conversely, an apparent underrepresentation of genetic syndromic disorders was evident in both major tribal groups. Possible explanations for these findings are discussed.

Adolescent↗
PubMed1988

Polyostotic fibrous dysplasia with cranial hyperostosis: new entity or most severe form of polyostotic fibrous dysplasia?

Polyostotic fibrous (McCune-Albright) dysplasia is an uncommon nonhereditable disorder characterized by localized or widespread cystic changes in the skeleton. The limb bones are predominantly affected; craniofacial involvement is rare. We have encountered a severely affected man, with the additional manifestation of massive craniofacial hyperostosis. It is questionable whether this condition is an autonomous entity or represents the end of the spectrum of severity of polyostotic fibrous dysplasia.

Adult↗
PubMed1988

A new form of hypohidrotic ectodermal dysplasia.

We report on a 17-yr-old young woman with an apparently new tricho-onycho-hypohidrotic ectodermal dysplasia. The manifestations include primary interdigital webbing, contractures of fingers and toes, conjunctivitis from narrowing of nasolacrimal ducts, and a small cortical opacity in the lens of the left eye. Psychosocial problems due to the cosmetic appearance are severe. Cause is uncertain.

Abnormalities, Multiple↗
PubMed1988

Partial trisomy 9--further delineation of the phenotype.

A patient with partial trisomy 9 (47,XX,+9pter----q22.1) had bilateral cleft lip and cleft palate, enophthalmos, severe micrognathia, small, apparently low-set ears, and dislocatable knees. The phenotypic findings are compared with those of other documented cases of total trisomy 9.

Abnormalities, Multiple↗
PubMed1988

Cutaneous manifestations of the Proteus syndrome.

The Proteus syndrome is a rare disorder in which the major manifestations are skeletal overgrowth, digital hypertrophy, exostoses of the skull, and hamartomatous tumors. Numerous skin lesions also occur. We treated six individuals, all of whom had the features unique to this syndrome of marked hypertrophy of the skin of the soles. The palms were similarly involved in two patients. Light microscopy of biopsy material from thickened areas of the soles showed elongation of the cytoplasm of the basal cells. Large epidermal nevi were present in three persons, as were linear macular lesions with areas of depigmentation and hyperpigmentation.

Abnormalities, Multiple↗
PubMed1987

Childhood deafness in the Indian population of Natal.

A study of 212 Indian children at the V.A. Naik School for Deaf was undertaken to determine the aetiology of their deafness. Undifferentiated autosomal recessive deafness was more frequent among Muslim patients--a population with a high incidence of consanguineous marriages--than among Tamils and Hindus. Although fewer than expected genetic syndromes were identified, Waardenburg's syndrome was present in 2% of the pupils. A firm diagnosis of acquired deafness was obtained in 32 children (15%).

Adolescent↗
PubMed1987

Proteus syndrome in southern Africa: natural history and clinical manifestations in six individuals.

Six individuals with Proteus syndrome have been investigated; 2 were adults and the others ranged in age from 2 to 11 years. They had a wide spectrum of manifestations and severity together with the hitherto unreported anomalies of penile hypertrophy, macro-orchidism, goiter, and failure of breast development. These findings were associated with normal endocrine function. Bizarre digital overgrowth, hemihypertrophy, thickened palms and soles, exostoses of the skull, and multiple hamartomata were common anomalies. Early overgrowth of limbs and digits occurred in several instances but the ultimate stature of 2 adults was normal. Surgical intervention offers cosmetic and orthopedic benefits, but these must be assessed in the light of potential post-operative complications.

Adult↗
PubMed1987

The Proteus syndrome: the magnetic resonance and radiological features.

The Proteus syndrome is a recently delineated group of skeletal and mesodermal malformations. Its characteristics include hemihypertrophy and fatty/lymphangiomatous masses. This description outlines the imaging sequences available to the radiologist. It is mainly concerned with the use of magnetic resonance imaging. This shows the extent of the mesodermal malformation with particular reference to the extent of intra abdominal infiltration.

Child, Preschool↗