Mutation analysis at the lipoprotein lipase gene locus in two South African kindreds

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dc.contributor.advisorHenderson, Howard Een_ZA
dc.contributor.authorHassan, Mohammed Fahrien_ZA
dc.date.accessioned2018-01-25T13:53:51Z
dc.date.available2018-01-25T13:53:51Z
dc.date.issued1996en_ZA
dc.description.abstractFamilial lipoprotein lipase (LPL) deficiency is a rare disorder of lipid metabolism associated with massive chylomicronaemia. Patients often present early in life with abdominal pain, pancreatitis, hepatosplenomegaly, eruptive xanthomata and zero to near zero levels of LPL activity in post-heparin plasma. The genetic heterogeneity underlying this disease is well-characterised and over 40 mutations have been described at the LPL gene loci. In this report three mutations are described at the LPL locus in two unrelated probands, namely, JJ (Kindred I) and LB (Kindred II). JJ presented early in childhood with signs and symptoms suggestive of LPL-deficiency. These were abdominal pain, hepatosplenomegaly and a markedly reduced LPL activity (38% of normal) in post-heparin plasma. DNA studies showed JJ to be a compound heterozygote for two point mutations in the LPL gene, these being, the I194T and C418Y substitutions, which occur in exons 5 and 9, respectively. Several mutation detection systems were set up as part of the characterisation and screening workup for these mutations; these were, allele-specific oligo nucleotide (ASO) hybridisation, "ARMS" PCR, PCR-SSCP, RT-PCR and DNA sequence analysis. In an earlier separate study, in vitro transfection results showed that the I194T mutant was catalytically inactive. Our findings of zero LPL activity in JJ's post-heparin plasma, implies that the C418Y mutation is also likely to produce an inactive protein product. The differences in LPL activity observed during the pre- and post-pubertal stages, if not artefactual, may be due to differential processing of LPL during human development with loss of activity post puberty. LB was first diagnosed with pancreatitis during the third trimester of her pregnancy. Although her child, BB, was successfully delivered by caesarean section, LB died of haemorrhagic pancreatitis with the marked hyperlipidaemia being suggestive of an underlying deficiency in LPL activity. Genomic DNA from her parents was first subjected to mutation analysis, since only slide specimens of post-mortem material were available from LB. Maternal DNA revealed a 0-A transition at nucleotide position 1516 which results in the substitution of lysine for glutamic acid at codon 421 in exon 9 (E421K), while paternal DNA show a single polymorphism at codon 108 in exon 3 of the LPL gene. Analysis of archival DNA obtained from histopathological slides of spleen tissue from LB also showed the E421K mutation. This mutation was also detected in her offspring, BB indicating maternal inheritance in three generations. While, this mutation may produce a catalytically defective product, the evidence is insufficient to propose a role for LPL deficiency as the primary cause of death in this patient, hence the search for a second mutation in the LPL gene of LB is imperative to establish this association.en_ZA
dc.identifier.apacitationHassan, M. F. (1996). <i>Mutation analysis at the lipoprotein lipase gene locus in two South African kindreds</i>. (Thesis). University of Cape Town ,Faculty of Health Sciences ,Division of Chemical Pathology. Retrieved from http://hdl.handle.net/11427/26967en_ZA
dc.identifier.chicagocitationHassan, Mohammed Fahri. <i>"Mutation analysis at the lipoprotein lipase gene locus in two South African kindreds."</i> Thesis., University of Cape Town ,Faculty of Health Sciences ,Division of Chemical Pathology, 1996. http://hdl.handle.net/11427/26967en_ZA
dc.identifier.citationHassan, M. 1996. Mutation analysis at the lipoprotein lipase gene locus in two South African kindreds. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Hassan, Mohammed Fahri AB - Familial lipoprotein lipase (LPL) deficiency is a rare disorder of lipid metabolism associated with massive chylomicronaemia. Patients often present early in life with abdominal pain, pancreatitis, hepatosplenomegaly, eruptive xanthomata and zero to near zero levels of LPL activity in post-heparin plasma. The genetic heterogeneity underlying this disease is well-characterised and over 40 mutations have been described at the LPL gene loci. In this report three mutations are described at the LPL locus in two unrelated probands, namely, JJ (Kindred I) and LB (Kindred II). JJ presented early in childhood with signs and symptoms suggestive of LPL-deficiency. These were abdominal pain, hepatosplenomegaly and a markedly reduced LPL activity (38% of normal) in post-heparin plasma. DNA studies showed JJ to be a compound heterozygote for two point mutations in the LPL gene, these being, the I194T and C418Y substitutions, which occur in exons 5 and 9, respectively. Several mutation detection systems were set up as part of the characterisation and screening workup for these mutations; these were, allele-specific oligo nucleotide (ASO) hybridisation, "ARMS" PCR, PCR-SSCP, RT-PCR and DNA sequence analysis. In an earlier separate study, in vitro transfection results showed that the I194T mutant was catalytically inactive. Our findings of zero LPL activity in JJ's post-heparin plasma, implies that the C418Y mutation is also likely to produce an inactive protein product. The differences in LPL activity observed during the pre- and post-pubertal stages, if not artefactual, may be due to differential processing of LPL during human development with loss of activity post puberty. LB was first diagnosed with pancreatitis during the third trimester of her pregnancy. Although her child, BB, was successfully delivered by caesarean section, LB died of haemorrhagic pancreatitis with the marked hyperlipidaemia being suggestive of an underlying deficiency in LPL activity. Genomic DNA from her parents was first subjected to mutation analysis, since only slide specimens of post-mortem material were available from LB. Maternal DNA revealed a 0-A transition at nucleotide position 1516 which results in the substitution of lysine for glutamic acid at codon 421 in exon 9 (E421K), while paternal DNA show a single polymorphism at codon 108 in exon 3 of the LPL gene. Analysis of archival DNA obtained from histopathological slides of spleen tissue from LB also showed the E421K mutation. This mutation was also detected in her offspring, BB indicating maternal inheritance in three generations. While, this mutation may produce a catalytically defective product, the evidence is insufficient to propose a role for LPL deficiency as the primary cause of death in this patient, hence the search for a second mutation in the LPL gene of LB is imperative to establish this association. DA - 1996 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1996 T1 - Mutation analysis at the lipoprotein lipase gene locus in two South African kindreds TI - Mutation analysis at the lipoprotein lipase gene locus in two South African kindreds UR - http://hdl.handle.net/11427/26967 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/26967
dc.identifier.vancouvercitationHassan MF. Mutation analysis at the lipoprotein lipase gene locus in two South African kindreds. [Thesis]. University of Cape Town ,Faculty of Health Sciences ,Division of Chemical Pathology, 1996 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/26967en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDivision of Chemical Pathologyen_ZA
dc.publisher.facultyFaculty of Health Sciencesen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherDNA Mutational Analysisen_ZA
dc.titleMutation analysis at the lipoprotein lipase gene locus in two South African kindredsen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMSc (Med)en_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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