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P Beighton

Publications and source records attributed to P Beighton.

At least 55 records · Page 3Linked to original sources
PubMed1996

Osteoporosis-pseudoglioma syndrome, a disorder affecting skeletal strength and vision, is assigned to chromosome region 11q12-13.

Osteoporosis-pseudoglioma syndrome (OPS) is an autosomal recessive disorder characterized by severe juvenile-onset osteoporosis and congenital or juvenile-onset blindness. The pathogenic mechanism is not known. Clinical, biochemical, and microscopic analyses suggest that OPS may be a disorder of matrix homeostasis rather than a disorder of matrix structure. Consequently, identification of the OPS gene and its protein product could provide insights regarding common osteoporotic conditions, such as postmenopausal and senile osteoporosis. As a first step toward determining the cause of OPS, we utilized a combination of traditional linkage analysis and homozygosity mapping to assign the OPS locus to chromosome region 11q12-13. Mapping was accomplished by analyzing 16 DNA samples (seven affected individuals) from three different consanguineous kindreds. Studies in 10 additional families narrowed the candidate region, supported locus homogeneity, and did not detect founder effects. The OPS locus maps to a 13-cM interval between D11S1298 and D11S971 and most likely lies in a 3-cM region between GSTP1 and D11S1296. At present, no strong candidate genes colocalize with OPS.

Alleles↗
PubMed1996

Mseleni joint disease--a molecular genetic approach to defining the aetiology.

Mseleni joint disease (MJD) is an unusual form of progressive and widespread degenerative osteoarthropathy that has been identified in several hundred people in the remote Mseleni region of northern Zululand. Affected individuals experience articular discomfort in childhood and may be seriously handicapped as adults, often requiring prosthetic hip joint replacement. Although the condition clusters in families, there is no evidence of Mendelian inheritance and assessment of affected kindreds has not shown any evidence of genomic imprinting. To date our molecular work-up has entailed the study of 47 affected individuals from MJD kindreds to investigate familial predisposition based on the inheritance of a subset of markers and/or genes on the human genome, particularly those associated with the cartilage matrix. In addition, we have collected blood specimens form 111 unaffected but unrelated individuals from the same population group in order to determine whether any relationship exists between genetic components of the human leucocyte antigen (HLA) system and the MJD phenotype. Our investigations show the following: (i) there is no association between MJD and the HLA system which has previously been associated with non-Mendelian genetic conditions; (ii) COL2A1, which has been implicated in some forms of spondylo-epiphyseal dysplasia, may be involved in at least a subset of MJD patients; and (iii) type VI collagen is overabundant in degenerated hip joint cartilage.

Black People↗
PubMed1996

Spondyloepimetaphyseal dysplasia with joint laxity (SEMDJL) in three neonates.

Spondyloepimetaphyseal dysplasia with joint laxity (SEMDJL) is a rare, recessive skeletal dysplasia previously reported almost exclusively in Afrikaans speaking South Africans. The condition has been well documented in infants and children. We report on three neonates with SEMDJL, whose presentation highlighted the difficulties inherent in the clinical diagnosis of this condition. SEMDJL may be more widespread than previously considered, as evidenced by the recent documentation of a Guatemalan child with the condition.

Abnormalities, Multiple↗
PubMed1995

Spondyloenchondromatosis: syndromic identity and evolution of the phenotype.

We present case details and depict the phenotypic manifestations of a dwarfing skeletal dysplasia in an adolescent boy who was first seen in early childhood. His initial clinical and radiological findings resembled those of pseudoachondroplasia but these subsequently metamorphosed to an appearance which was diagnostic of spondyloenchondromatosis. It is uncertain whether this latter condition is a homogeneous entity or a group of heterogeneous disorders. Pedigree data were consistent with autosomal recessive inheritance.

Achondroplasia↗
PubMed1995

An eighth locus for autosomal dominant retinitis pigmentosa is linked to chromosome 17q.

Retinitis pigmentosa is one of the most common causes of severe visual handicap in middle to late life. Prior to this report, seven loci had previously been mapped for the autosomal dominant form of this disorder (adRP). We now report the identification of a novel adRP locus on chromosome 17q. To map the new locus, we performed linkage analysis with microsatellite markers in a large South African kindred. After exclusion of 13 RP candidate gene loci (including rhodopsin and peripherin-RDS), we obtained significant positive lod scores at zero recombination fraction (theta = 0) for D17S808 (Z = 4.63) and D17S807 (Z = 5.69). Multipoint analysis gave a maximum lod score of 8.28 between these two markers. From haplotype analysis, the disease locus lies in the interval between markers D17S809 and D17S942. Three candidate genes for retinal dystrophies map to this chromosomal region and these genes are currently being investigated for possible involvement with adRP in this family.

Adult↗
PubMed1995

Localization of the Schwartz-Jampel syndrome (SJS) locus to chromosome 1p34-p36.1 by homozygosity mapping.

Schwartz-Jampel syndrome (SJS, MIM 255800), also known as chondrodystrophic myotonia, is a rare autosomal recessive disorder characterized by generalized myotonia, skeletal abnormalities and facial dysmorphism. Using homozygosity mapping, we localized the SJS locus to chromosome 1p34-p36.1 in a 8 cM interval flanked by markers D1S199 and D1S234. Families of different ethnic backgrounds (Tunisia and South Africa) showed genetic linkage to the same locus. Moreover, one Algerian family also demonstrated evidence of genetic linkage to 1p34-p36.1. Taken altogether, our results suggest genetic homogeneity, at least in the group of families analyzed.

Chromosome Mapping↗
PubMed1994

Autosomal dominant (Beukes) premature degenerative osteoarthropathy of the hip joint unlinked to COL2A1.

Molecular investigations have been undertaken in several separate large South African families with autosomal dominant skeletal dysplasias in which premature degenerative osteoarthropathy of the hip joint was the major manifestation. There are sometimes additional minor changes in the spine and these conditions fall into the general spondyloepiphyseal dysplasia (SED) nosological category. In some kindreds, linkage between phenotype and the type II collagen gene (COL2A1) has been established, while in others there is no linkage. We have now completed molecular linkage investigations in an Afrikaner family named Beukes, in which 47 members in 6 generations have premature osteoarthropathy of the hip joint. A LOD score of minus infinity indicates that this condition is not the result of a defect of the COL2A1 gene.

Chromosome Aberrations↗
PubMed1994

Brachyolmia: an autosomal dominant form.

We have investigated a mother and son of South African Xhosa stock who presented with short-trunk dwarfism and kyphoscoliosis. Radiographs show the marked platyspondyly and vertebral irregularity characteristic of brachyolmia. Our patients provide further evidence for the existence of an autosomal dominant form and supports the theory of heterogeneity in this rare group of genetic skeletal disorders. Molecular investigations in this South African family are currently underway but at present the basis defect of brachyolmia remains unknown.

Adult↗
PubMed1994

Bone dysplasias of infancy in the Vienna collection.

The Vienna Museum of Pathological Anatomy contains a vast collection of abnormal skeletons. We have appraised this material and attempted to establish firm diagnoses of specific genetic disorders in terms of modern syndromic concepts. A number of the skeletons in the museum are those of deceased neonates; in many instances it was impossible to reach a diagnosis on the basis of the outward appearance but radiographic investigations confirmed diagnoses including osteogenesis imperfecta type II, thanatophoric dysplasia, achondroplasia and achondrogenesis. The Vienna collection represents a priceless resource for the investigation of genetic skeletal disorders of this type.

Achondroplasia↗
PubMed1994

A new locus for autosomal dominant retinitis pigmentosa on the short arm of chromosome 17.

Retinitis pigmentosa (RP) is a group of genetically and clinically heterogeneous retinopathies, some of which have been shown to result from mutations in two different known retinal genes, rhodopsin (3q) and peripherin-rds (6p). Three additional anonymous loci at 7p, 7q and pericentric 8 have been implicated by linkage studies. There are still, however, a few families in which all known loci have been excluded. In this report we present data indicating a location, on the short arm of chromosome 17, for the autosomal dominant RP (ADRP) locus in a large South African (SA) family of British ancestry. Positive two-point lod scores have been obtained for nine markers (D17S938, Z = 5.43; D17S796, Z = 4.82; D17S849, Z = 3.6; D17S786, Z = 3.55; TP53, Z = 3.55; D17S578, Z = 3.29; D17S960, Z = 3.16; D17S926, Z = 1.51; D17S804, Z = 0.47 all at theta = 0.10 except D17S804 and D17S926, theta = 0.20). These data provide definitive evidence for the localization of an ADRP gene on chromosome 17p. The human recoverin gene has been localized to 17p13.1 and was consequently a prime candidate for ADRP in the family studied. However, mutation screening of the three exons of this gene failed to produce any evidence of recoverin being the gene involved in the pathogenesis of ADRP in this SA family.

Calcium-Binding Proteins↗
PubMed1994

Genetic mapping of retinitis pigmentosa--implications for South African patients.

The term 'retinitis pigmentosa' (RP) encompasses a group of hereditary degenerative disorders of the retina, which are both genetically and clinically heterogeneous. The finding of molecular markers for certain forms of RP potentially allows for presymptomatic and prenatal diagnosis of a proportion of RP families. These developments and their implications for affected South African families are highlighted in this article.

Chromosome Mapping↗
PubMed1994

Duchenne and Becker muscular dystrophy prevalence in South Africa and molecular findings in 128 persons affected.

A genetic service for Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) was initiated in Cape Town in 1987. Of the 143 DMD patients diagnosed during the period 1987-1992, 66 had a familial pattern of inheritance and 77 were apparently sporadic. Twenty BMD patients were identified, of whom 12 had other affected relatives and 8 were sporadic. Overall minimum prevalence rates of 1/100,000 for DMD and 1/755,000 for BMD were calculated. A markedly low DMD prevalence in the indigenous black population (1/250,000) contributed to the overall low DMD prevalence in South Africa when compared with that in the UK (1/40,000). By means of molecular methods, the diagnosis in 42% of the affected DMD males was confirmed by detection of deletions in the dystrophin gene. Deletions were identified in 50% of Indian, white and mixed ancestry patients. In contrast, only 22% of blacks had identifiable deletions. DMD appears to be underrepresented in the black population; the low deletion frequency in this group suggests that unique mutations not detectable by methods used in this study may be more frequent in these patients than in the other populations. The increased DMD frequency in Indians corroborates findings reported from the UK.

Chromosome Deletion↗
PubMed1993

Rod-cone dystrophy, sensorineural deafness, and renal dysfunction: an autosomal recessive syndrome?

An autosomal recessive syndrome of progressive rod-cone dystrophy, sensorineural deafness, and renal dysfunction was identified in 14 children in 9 Afrikaner families in South Africa. The renal involvement, which is of the Fanconi type, leads to rickets-like skeletal changes and kidney failure. Each of the children was initially misdiagnosed as having retinitis pigmentosa or Usher syndrome, on a basis of minor retinal pigmentation. This condition, which appears to be a hitherto undocumented entity, warrants differentiation from these disorders.

Adolescent↗