Browsing by Author "Marx, M. P."

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    The identification of two low-density lipoprotein receptor gene mutations in South African familial hypercholesterolaemia
    (Health & Medical Publishing Group, 1989) Kotze, M. J.; Langenhoven, E.; Warnich, Louise; Du Plessis, L.; Marx, M. P.; Oosthuizen, C. J. J.; Retief, A. E.
    Two point mutations were discovered in the low-density lipoprotein genes of patients with familial hypercholesterolaemia (FH). Defective genes were cloned and/or amplified by the polymerase chain reaction (PCR) method and the DNA sequences determined. A guanine to adenine base transition in exon 4 was found to be the molecular defect in 20% of cases of FH in the Afrikaner population. A second mutation, a guanine to adenine base substitution in exon 9, was identified in two homozygous FH individuals. Restriction enzyme analysis of PCR-amplified DNA from blood and tissue samples now permits accurate diagnosis of these mutations.
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    Inherited colon cancers
    (Health & Medical Publishing Group, 2000) Goldberg, P. A.; Madden, M. V.; Harocopos, C.; Grobbelaar, J. J.; Kotze, M. J.; Marx, M. P.; De Jong, G.
    Grobbelaar et al.' and Ramesar et al.' (in this issue) have identified germline mutations in certain families with h"o different types of inherited colorectal cancers. This means that blood tests are now available in South Africa for clinical use in these particular families. Within the families these DNA-based tests can separate individuals with the mutation that causes cancer from those who do not have it. Those with a mutation may pass the family-specific mutation to their children.
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    Molecular characterisation of a low-frequency mutation in exon 8 of the human low-density lipoprotein receptor gene
    (Health & Medical Publishing Group, 1989) Kotze, M. J.; Langenhoven, E.; Warnich, Louise; Marx, M. P.; Retief, A. E.
    The prevalence of familial hypercholesterolaemia (FH), an autosomal dominant disease characterised by raised low-density lipoprotein (LDL) cholesterol levels, is at least five times higher in the white Afrikaner population than in most other population groups in the world. A founder gene effect has been suggested to explain this abnormally high frequency. Detection of a polymorphic Stu I site in the 5' region of the LDL receptor gene and association of both restriction fragment length polymorphism alleles with FH in Afrikaners, indicated the existence of at least two founder members of the disease in this population. DNA from a hetero-allelic FH homozygote from this South African group has been analysed through genomic cloning and sequencing. The DNA polymorphic site is caused by a single guanine to adenine transition within exon 8 of the LDL receptor gene and can be used in the determination of haplotype-associated defects.