ABCA1 p.Gln1038*
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[hide] Characterization of antioxidant/anti-inflammatory ... Clin Chim Acta. 2011 Jun 11;412(13-14):1213-20. Epub 2011 Mar 21. Daniil G, Phedonos AA, Holleboom AG, Motazacker MM, Argyri L, Kuivenhoven JA, Chroni A
Characterization of antioxidant/anti-inflammatory properties and apoA-I-containing subpopulations of HDL from family subjects with monogenic low HDL disorders.
Clin Chim Acta. 2011 Jun 11;412(13-14):1213-20. Epub 2011 Mar 21., [PMID:21420943]
Abstract [show]
BACKGROUND: Genetic factors regulate both high-density lipoprotein (HDL) levels and functionality, thus affecting HDL antiatherogenic properties. We characterized the HDL antioxidant/anti-inflammatory properties and apoA-I-containing subpopulations in families with monogenic low HDL disorders. METHODS: Subjects with mutations in apolipoprotein A-I (apoA-I), ATP-binding cassette transporter A1 (ABCA1) or lecithin:cholesterol acyltransferase (LCAT) and family controls were studied. HDL antioxidant/anti-inflammatory properties were assayed by an in vitro fluorometric method and HDL-associated paraoxonase-1 (PON1), platelet activating factor-acetylhydrolase (PAF-AH), LCAT, malondialdehyde (MDA), PAF and serum amyloid A (SAA) were measured. ApoA-I-containing HDL subpopulations were analyzed by two-dimensional non-denaturing gel electrophoresis. RESULTS: ApoA-I heterozygotes and subjects with partial or complete ABCA1 or LCAT deficiency had HDL with reduced antioxidant/anti-inflammatory properties and increased MDA levels. HDL-PON1 activity was reduced in apoA-I heterozygotes and in subjects with complete ABCA1 deficiency. HDL-PAF-AH activity was reduced in subjects with partial or complete ABCA1 deficiency or complete LCAT deficiency. HDL-LCAT activity was reduced in all LCAT mutation carriers. HDL-PAF levels were increased in apoA-I heterozygotes. HDL-SAA levels were increased in subjects with complete ABCA1 deficiency. ApoA-I, ABCA1 and LCAT heterozygotes were depleted of the large alpha1 HDL subpopulation. Subjects with complete LCAT deficiency showed mostly the small alpha4 HDL subpopulation and subjects with complete ABCA1 deficiency the alpha4 and prebeta HDL subpopulations. CONCLUSIONS: This study shows that mutations in apoA-I, ABCA1 and LCAT have direct effect on the antioxidant/anti-inflammatory properties of HDL. Furthermore, our study shows the effect of specific mutations on the apoA-I-containing HDL subpopulation profiles.
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56 Subjects We examined serum obtained from 3 heterozygotes for the apoA-I (NM_000039) mutation p.L202P (n=3; mutation was previously denoted as L178P [14]), 6 heterozygotes for ABCA1 (NM_005502) mutations(p.C1477R,n=3;p.L1056P,n=3),2compoundheterozygotes for ABCA1 mutations (p.C1477R/IVS25+1GNC; p.Q1038X/p.N1800H), 1 homozygote for the ABCA1 mutation p.L1056P, 12 heterozygotes for LCAT (NM_000229) mutations (p.P34Q, n=1; p.Y107X, n=1; p.T147I, n=4; p.N155D, n=2; p.I202T, n=1; p.R322C, n=2, p.V333M, n=1), 3 compound heterozygotes for the LCAT mutation p.T147I/IVS4-22TNC and 1 homozygote for the LCAT mutation p.N155D.
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ABCA1 p.Gln1038* 21420943:56:297
status: NEW150 Male/female TC HDL-c apoA-I apoA-II LDL-c apoB TG apoA-I mutation carriers Unaffected (n=3) 1/2 179±27 45±3 163±13 30±1 131±22 97±15 97±25 Heterozygotes (n=3) 1/2 141±12* 20±14* 87±38* 19±6* 113±5 85±6 97±45 ABCA1 mutation carriers Unaffected (n=8) 4/4 171±56 57±15 160±29 30±4 111±23 84±12 85±20 Heterozygotes (n=6) 3/3 179±64 37±7** 124±12** 28±2 129±35 98±22 90±44 Compound heterozygote 1c (n=1) 1/0 54 6 4 2 44 75 138 Compound heterozygote 2d (n=1) 0/1 220 3 7 ndb 173 192 387 Homozygote (n=1) 0/1 63 0.8 nd nd 61 81 87 LCAT mutation carriers Unaffected (n=7) 5/2 199±32 49±13 166±19 31±2 134±28 100±20 123±58 Heterozygotes (n=12) 8/4 166±47 32±11** 122±27*** 26±5* 122±38 97±28 115±49 Compound heterozygotes (n=3) 0/3 140±24* 5±1*** 48±8*** 3.8±0.3*** 118±17 102±27 244±103* Homozygote (n=1) 1/0 107 3 58 4 77 118 279 a Values presented as mean±SD (mg/dl); b nd, not detectable; c ABCA1[p.C1477R/IVS25+1GNC]; d ABCA1[p.Q1038X/ p.N1800H].
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ABCA1 p.Gln1038* 21420943:150:1174
status: NEW163 A previous study has shown that heterozygotes for ABCA1 mutation p.C1477R, but not for ABCA1 mutation p.L1056P, have increased CAD compared to unaffected family members [24,25].
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ABCA1 p.Gln1038* 21420943:163:144
status: NEWX
ABCA1 p.Gln1038* 21420943:163:178
status: NEW166 Compound heterozygotes for ABCA1 mutations * * 0 10000 20000 30000 40000 50000 60000 70000 L1056P L1056P C1477R C1477R ** ** C1477R/ IVS25+1G>C Q1038X/ N1800H C1477R/ IVS25+1G>C Q1038X/ N1800H 0.0 2.5 5.0 7.5 10.0 SAA/HDL-c(RLU) ** 0 10 20 30 40 *** 0 1 2 3 PAF-AHactivity (nmolCE/h) A B C D * ** HDL C HDL Het HDL Com HDL Hom HDL C HDL Het HDL Com HDL Hom HDL C HDL Het HDL Com HDL Hom DCF LDL HDL C HDL HetHDL C +LDL HDL Het + LDL HDL Com HDL Com +LDL Fluoresence(AU) MDA/HDL-c(RLU) Fig. 2.
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ABCA1 p.Gln1038* 21420943:166:144
status: NEWX
ABCA1 p.Gln1038* 21420943:166:178
status: NEW177 A compound heterozygote for ABCA1 mutations p.Q1038X/ p.N1800H did not present with CAD [25].
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ABCA1 p.Gln1038* 21420943:177:46
status: NEW147 Male/female TC HDL-c apoA-I apoA-II LDL-c apoB TG apoA-I mutation carriers Unaffected (n=3) 1/2 179&#b1;27 45&#b1;3 163&#b1;13 30&#b1;1 131&#b1;22 97&#b1;15 97&#b1;25 Heterozygotes (n=3) 1/2 141&#b1;12* 20&#b1;14* 87&#b1;38* 19&#b1;6* 113&#b1;5 85&#b1;6 97&#b1;45 ABCA1 mutation carriers Unaffected (n=8) 4/4 171&#b1;56 57&#b1;15 160&#b1;29 30&#b1;4 111&#b1;23 84&#b1;12 85&#b1;20 Heterozygotes (n=6) 3/3 179&#b1;64 37&#b1;7** 124&#b1;12** 28&#b1;2 129&#b1;35 98&#b1;22 90&#b1;44 Compound heterozygote 1c (n=1) 1/0 54 6 4 2 44 75 138 Compound heterozygote 2d (n=1) 0/1 220 3 7 ndb 173 192 387 Homozygote (n=1) 0/1 63 0.8 nd nd 61 81 87 LCAT mutation carriers Unaffected (n=7) 5/2 199&#b1;32 49&#b1;13 166&#b1;19 31&#b1;2 134&#b1;28 100&#b1;20 123&#b1;58 Heterozygotes (n=12) 8/4 166&#b1;47 32&#b1;11** 122&#b1;27*** 26&#b1;5* 122&#b1;38 97&#b1;28 115&#b1;49 Compound heterozygotes (n=3) 0/3 140&#b1;24* 5&#b1;1*** 48&#b1;8*** 3.8&#b1;0.3*** 118&#b1;17 102&#b1;27 244&#b1;103* Homozygote (n=1) 1/0 107 3 58 4 77 118 279 a Values presented as mean&#b1;SD (mg/dl); b nd, not detectable; c ABCA1[p.C1477R/IVS25+1GNC]; d ABCA1[p.Q1038X/ p.N1800H].
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ABCA1 p.Gln1038* 21420943:147:1124
status: NEW174 A compound heterozygote for ABCA1 mutations p.Q1038X/ p.N1800H did not present with CAD [25].
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ABCA1 p.Gln1038* 21420943:174:46
status: NEW[hide] Plasma levels of 27-hydroxycholesterol in humans a... Atherosclerosis. 2011 Feb;214(2):448-55. Epub 2010 Nov 3. Karuna R, Holleboom AG, Motazacker MM, Kuivenhoven JA, Frikke-Schmidt R, Tybjaerg-Hansen A, Georgopoulos S, van Eck M, van Berkel TJ, von Eckardstein A, Rentsch KM
Plasma levels of 27-hydroxycholesterol in humans and mice with monogenic disturbances of high density lipoprotein metabolism.
Atherosclerosis. 2011 Feb;214(2):448-55. Epub 2010 Nov 3., [PMID:21130455]
Abstract [show]
Secretion of 27-hydroxycholesterol (27OHC) from macrophages is considered as an alternative to HDL-mediated reverse transport of excess cholesterol. We investigated 27OHC-concentrations in plasma of humans and mice with monogenic disorders of HDL metabolism. As compared to family controls mutations in the genes for apolipoprotein A-I, ATP binding cassette transporter (ABC) A1 and lecithin:cholesterol acylstransferase (LCAT) were associated with reduced concentrations of both HDL-cholesterol and HDL-27OHC whereas mutations in the genes for cholesterylester transfer protein (CETP), scavenger receptor type BI and hepatic lipase were associated with elevated HDL concentrations of either sterol. Compared to family controls and relative to the concentrations of total 27OHC and cholesterol, lower 27OHC-ester but normal cholesterylester levels were found in HDL of heterozygous LCAT mutation carriers and nonHDL of heterozygous CETP mutation carriers. In family controls, LCAT activity and CETP mass were more strongly correlated with 27OHC-ester than cholesterylester concentrations in HDL and nonHDL, respectively. These findings suggest that the formation and transfer of 27OHC-esters are more sensitive to reduced activities of LCAT and CETP, respectively, than the formation and transfer of cholesterylesters. 27OHC plasma levels were also decreased in apoA-I-, ABCA1- or LCAT-knockout mice but increased in SR-BI-knockout mice. Transplantation of ABCA1- and/or ABCG1-deficient bone marrow into LDL receptor deficient mice decreased plasma levels of 27OHC. In conclusion, mutations or absence of HDL genes lead to distinct alterations in the quantity, esterification or lipoprotein distribution of 27OHC. These findings argue against the earlier suggestion that 27OHC-metabolism in plasma occurs independently of HDL.
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63 Mutated gene Number of defective alleles Mutationa Age (year) Cholesterol (mM) HDL-cholesterol (mM) NonHDL-cholesterol (mM) Triglyceride (mM) Number of smokers Dutch APOA1 0 27 ± 14 4.59 ± 0.68 1.16 ± 0.06 3.43 ± 0.63 1.09 ± 0.29 0 1 p.L202P (c.605T > C) 26 ± 17 3.61 ± 0.31 0.51 ± 0.35 3.10 ± 0.06 1.09 ± 0.51 0 ABCA1 0 44 ± 20 4.39 ± 0.89 1.47 ± 0.39 2.92 ± 0.62 0.95 ± 0.22 1 1 p.L1056P (c.3167T > C) or p.C1477R (c.4429T > C) 57 ± 11 4.47 ± 1.08 0.94 ± 0.17 3.53 ± 0.96 1.01 ± 0.05 0 2 p.L1056P (c.3167T > C, homozygote) or p.Q1038X (c.3112C > T) + p.N1800H (c.5398A > C) or p.C1477R (c.4429T > C) + IVS25 + 1G > C 53 ± 10 2.89 ± 2.39 NDb NDb 2.29 ± 1.80 0 LCAT 0 49 ± 9 4.96 ± 0.86 1.33 ± 0.38 3.62 ± 0.97 1.29 ± 0.66 0 1 p.T147I (c.440C > T), p.R322C (c.964C > T), p.N155D (c.463A > G), p.P34Q (c.101C > A), p.Y107X (c.321C > A), p.I202T (c.605T > C) or p.V333M (c.997G > A) 43 ± 13 4.27 ± 1.21 0.81 ± 0.28 3.45 ± 1.08 1.30 ± 0.55 1 2 p.T147I (c.440C > T) + V333M 69 ± 4 3.26 ± 0.19 NDb NDb 2.11 ± 0.49 0 SR-BI 0 54 ± 19 4.77 ± 0.89 1.17 ± 0.33 3.60 ± 0.79 1.21 ± 0.64 0 1 p.P297S (c.889C > T) 45 ± 22 4.46 ± 1.21 1.73 ± 0.56 2.73 ± 0.81 0.97 ± 0.28 1 CETP 0 36 ± 16 4.14 ± 0.51 1.30 ± 0.21 2.85 ± 0.48 0.87 ± 0.40 1 1 IVS7 + 1 (G > T) 39 ± 18 4.20 ± 0.51 1.56 ± 0.29 2.64 ± 0.77 0.76 ± 0.32 1 HL (LIPC) 0 45 ± 19 5.23 ± 0.99 1.61 ± 0.54 3.62 ± 0.90 1.45 ± 1.05 3 1 p.S289F (c.866C > T) 45 ± 15 4.92 ± 1.21 2.00 ± 0.68 2.92 ± 0.86 1.14 ± 0.43 1 Danish Controls 0 50 ± 9 5.84 ± 1.24 1.54 ± 0.24 4.30 ± 1.23 1.34 ± 0.62 1 APOA1 1 p.L168R (c.503T > G) 63 ± 4 4.70 ± 0.28 0.85 ± 0.07 3.85 ± 0.35 1.27 ± 0.70 0 CETP 1 p.S349Y (c.1046C > A) 59 ± 4 6.85 ± 2.05 3.05 ± 1.77 3.80 ± 0.28 0.86 ± 0.23 1 Values represent mean ± SD.
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ABCA1 p.Gln1038* 21130455:63:630
status: NEW62 Mutated gene Number of defective alleles Mutationa Age (year) Cholesterol (mM) HDL-cholesterol (mM) NonHDL-cholesterol (mM) Triglyceride (mM) Number of smokers Dutch APOA1 0 27 &#b1; 14 4.59 &#b1; 0.68 1.16 &#b1; 0.06 3.43 &#b1; 0.63 1.09 &#b1; 0.29 0 1 p.L202P (c.605T > C) 26 &#b1; 17 3.61 &#b1; 0.31 0.51 &#b1; 0.35 3.10 &#b1; 0.06 1.09 &#b1; 0.51 0 ABCA1 0 44 &#b1; 20 4.39 &#b1; 0.89 1.47 &#b1; 0.39 2.92 &#b1; 0.62 0.95 &#b1; 0.22 1 1 p.L1056P (c.3167T > C) or p.C1477R (c.4429T > C) 57 &#b1; 11 4.47 &#b1; 1.08 0.94 &#b1; 0.17 3.53 &#b1; 0.96 1.01 &#b1; 0.05 0 2 p.L1056P (c.3167T > C, homozygote) or p.Q1038X (c.3112C > T) + p.N1800H (c.5398A > C) or p.C1477R (c.4429T > C) + IVS25 + 1G > C 53 &#b1; 10 2.89 &#b1; 2.39 NDb NDb 2.29 &#b1; 1.80 0 LCAT 0 49 &#b1; 9 4.96 &#b1; 0.86 1.33 &#b1; 0.38 3.62 &#b1; 0.97 1.29 &#b1; 0.66 0 1 p.T147I (c.440C > T), p.R322C (c.964C > T), p.N155D (c.463A > G), p.P34Q (c.101C > A), p.Y107X (c.321C > A), p.I202T (c.605T > C) or p.V333M (c.997G > A) 43 &#b1; 13 4.27 &#b1; 1.21 0.81 &#b1; 0.28 3.45 &#b1; 1.08 1.30 &#b1; 0.55 1 2 p.T147I (c.440C > T) + V333M 69 &#b1; 4 3.26 &#b1; 0.19 NDb NDb 2.11 &#b1; 0.49 0 SR-BI 0 54 &#b1; 19 4.77 &#b1; 0.89 1.17 &#b1; 0.33 3.60 &#b1; 0.79 1.21 &#b1; 0.64 0 1 p.P297S (c.889C > T) 45 &#b1; 22 4.46 &#b1; 1.21 1.73 &#b1; 0.56 2.73 &#b1; 0.81 0.97 &#b1; 0.28 1 CETP 0 36 &#b1; 16 4.14 &#b1; 0.51 1.30 &#b1; 0.21 2.85 &#b1; 0.48 0.87 &#b1; 0.40 1 1 IVS7 + 1 (G > T) 39 &#b1; 18 4.20 &#b1; 0.51 1.56 &#b1; 0.29 2.64 &#b1; 0.77 0.76 &#b1; 0.32 1 HL (LIPC) 0 45 &#b1; 19 5.23 &#b1; 0.99 1.61 &#b1; 0.54 3.62 &#b1; 0.90 1.45 &#b1; 1.05 3 1 p.S289F (c.866C > T) 45 &#b1; 15 4.92 &#b1; 1.21 2.00 &#b1; 0.68 2.92 &#b1; 0.86 1.14 &#b1; 0.43 1 Danish Controls 0 50 &#b1; 9 5.84 &#b1; 1.24 1.54 &#b1; 0.24 4.30 &#b1; 1.23 1.34 &#b1; 0.62 1 APOA1 1 p.L168R (c.503T > G) 63 &#b1; 4 4.70 &#b1; 0.28 0.85 &#b1; 0.07 3.85 &#b1; 0.35 1.27 &#b1; 0.70 0 CETP 1 p.S349Y (c.1046C > A) 59 &#b1; 4 6.85 &#b1; 2.05 3.05 &#b1; 1.77 3.80 &#b1; 0.28 0.86 &#b1; 0.23 1 Values represent mean &#b1; SD.
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ABCA1 p.Gln1038* 21130455:62:610
status: NEW[hide] Identification and characterization of novel loss ... Atherosclerosis. 2010 Dec;213(2):492-8. Epub 2010 Aug 26. Candini C, Schimmel AW, Peter J, Bochem AE, Holleboom AG, Vergeer M, Dullaart RP, Dallinga-Thie GM, Hovingh GK, Khoo KL, Fasano T, Bocchi L, Calandra S, Kuivenhoven JA, Motazacker MM
Identification and characterization of novel loss of function mutations in ATP-binding cassette transporter A1 in patients with low plasma high-density lipoprotein cholesterol.
Atherosclerosis. 2010 Dec;213(2):492-8. Epub 2010 Aug 26., [PMID:20880529]
Abstract [show]
OBJECTIVES: The current literature provides little information on the frequency of mutations in the ATP-binding cassette transporter A1 (ABCA1) in patients with low high-density lipoprotein cholesterol (HDL) levels that are referred to the clinic. In 78 patients with low plasma levels of HDL cholesterol that were referred to our clinic, we routinely screened for ABCA1 gene mutations and studied the functionality of newly identified ABCA1 missense mutations. METHODS: The coding regions and exon-intron boundaries of the ABCA1 gene were sequenced in 78 subjects with HDL cholesterol levels below the 10th percentile for age and gender. Novel mutations were studied by assessing cholesterol efflux capacity (using apolipoprotein A-I as acceptor) after transient expression of ABCA1 variants in BHK cells. RESULTS: Sixteen out of 78 patients (21%) were found to carry 19 different ABCA1 gene variants (1 frameshift, 2 splice-site, 4 nonsense and 12 missense variation) of which 14 variations were novel. Of three patients with homozygous mutations and three patients having compound heterozygous mutations only one patient presented with the clinical characteristics of Tangier Disease (TD) in the presence of nearly complete HDL deficiency. Seven out of eight newly identified ABCA1 missense mutations were found to exhibit a statistically significant loss of cholesterol efflux capacity. CONCLUSION: This study shows that one out of five patients who are referred to our hospital because of low HDL cholesterol levels have a functional ABCA1 gene mutation. It is furthermore demonstrated that in vitro studies are needed to assess functionality of ABCA1 missense mutations.
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76 Patients (gender, age) Amino acida (nucleotidea ) change TC TG LDL-c HDL-c Clinical manifestations of TD CVD Other relevant clinical data Homozygotes Patient 1 (female, 42) p.L1056P (c.3167T > C) 2.4 0.9 1.99 <0.10 Absent CAD Thrombocytopenia Patient 2 (male, 40) p.Wl747X (c.5240G > A) 1.76 1.93 0.52 0.1-0.3 Neuropathy, splenomegaly, thrombocytopenia Mild stenosis (20-30%) of coronary arteries None Patient 3 (male, 55) p.F593L (c.1779C > G) 4.4 1.4 3.6 <0.10 Absent CAD None p.E1253K (c.3757G > A) Compound heterozygotes Patient 4 (female, 63) p.Q1038X (c.3112C > T) 6.68 2.72 5.4 <0.10 Absent None None p.N1800H (c.5398A > C) [32] Patient 5 (female, 28) p.T1512M (c.4535C > T) 4.42 1.83 3.46 0.1 Absent None None p.N1800H (c.5398A > C) [32] p.C978fsX988 (c.2934delT) Patient 6 (female, 17) p.D575G (c.1724A > G) 4.96 2.84 4.35 <0.10 Absent None DM1 p.C1941R(c.5821T > C) Heterozygotes Patient 7 (male, 42) p.S100C (c.299C > G) 8.5 8.7 4.3 0.3 N.A. None None Patient 8 (male, 58) p.E1172D (c.3516G > C) [33] 6.4 2.7 4.1 0.9 N.A. None None Patient 9 (male, 35) p.S1181F (c.3542C > T) [17] 2.9 0.31 1.88 0.88 N.A. None None Patient 10 (male, 48) p.C1477R (c.4429T > C) [13] 2.01 1.4 0.92 0.46 N.A. CAD None Patient 11 (male, 68) p.V1858A (c.5573T > C) 4.9 3.78 2.41 0.75 N.A. CAD None Patient 12 (female, 36) p.N1800H (c.5398A > C) [32] 4.6 1.2 4 <0.10 N.A. None DM2, obesity Patient 13 (male, 67) p.R282X (c.844C > T) [34] 3.2 1.21 2.14 0.51 N.A. None DM2 Patient 14 (female, 42) p.W424X (c.1272G > A) 2.07 1.04 1.39 0.21 N.A. None None Patient 15 (female, 52) N.A. - (IVS11 - 1G > A) 5.51 3.51 3.28 0.56 N.A. None Hypothyroidism, hypertension Patient 16 (female, 54) N.A. - (IVS48 + 2T > C) 3.29 1.92 1.94 0.49 N.A. None DM2, hypertension a Nomenclature based on guidelines of Human Genome Variation Society.
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ABCA1 p.Gln1038* 20880529:76:550
status: NEW89 In ABCA1, we identified 14 novel and 5 known genetic variations in 16 subjects including one frameshift (p.C978fsX988), 2 splice-site (IVS11-1G > C and IVS48 + 2T > C), 4 nonsense (p.R282X, p.W424X, p.Q1038X, p.Wl747X) and 12 missense variations (p.S100C, p.D575G, p.F593L, p.L1056P, p.E1172D, p.S1181F, p.E1253K, p.C1477R, p.T1512M, p.N1800H, p.V1858A, p.C1941R).
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ABCA1 p.Gln1038* 20880529:89:201
status: NEW[hide] Update on the molecular biology of dyslipidemias. Clin Chim Acta. 2015 Nov 4. pii: S0009-8981(15)30036-X. doi: 10.1016/j.cca.2015.10.033. Ramasamy I
Update on the molecular biology of dyslipidemias.
Clin Chim Acta. 2015 Nov 4. pii: S0009-8981(15)30036-X. doi: 10.1016/j.cca.2015.10.033., [PMID:26546829]
Abstract [show]
Dyslipidemia is a commonly encountered clinical condition and is an important determinant of cardiovascular disease. Although secondary factors play a role in clinical expression, dyslipidemias have a strong genetic component. Familial hypercholesterolemia is usually due to loss-of-function mutations in LDLR, the gene coding for low density lipoprotein receptor and genes encoding for proteins that interact with the receptor: APOB, PCSK9 and LDLRAP1. Monogenic hypertriglyceridemia is the result of mutations in genes that regulate the metabolism of triglyceride rich lipoproteins (eg LPL, APOC2, APOA5, LMF1, GPIHBP1). Conversely familial hypobetalipoproteinemia is caused by inactivation of the PCSK9 gene which increases the number of LDL receptors and decreases plasma cholesterol. Mutations in the genes APOB, and ANGPTL3 and ANGPTL4 (that encode angiopoietin-like proteins which inhibit lipoprotein lipase activity) can further cause low levels of apoB containing lipoproteins. Abetalipoproteinemia and chylomicron retention disease are due to mutations in the microsomal transfer protein and Sar1b-GTPase genes, which affect the secretion of apoB containing lipoproteins. Dysbetalipoproteinemia stems from dysfunctional apoE and is characterized by the accumulation of remnants of chylomicrons and very low density lipoproteins. ApoE deficiency can cause a similar phenotype or rarely mutations in apoE can be associated with lipoprotein glomerulopathy. Low HDL can result from mutations in a number of genes regulating HDL production or catabolism; apoAI, lecithin: cholesterol acyltransferase and the ATP-binding cassette transporter ABCA1. Patients with cholesteryl ester transfer protein deficiency have markedly increased HDL cholesterol. Both common and rare genetic variants contribute to susceptibility to dyslipidemias. In contrast to rare familial syndromes, in most patients, dyslipidemias have a complex genetic etiology consisting of multiple genetic variants as established by genome wide association studies. Secondary factors, obesity, metabolic syndrome, diabetes, renal disease, estrogen and antipsychotics can increase the likelihood of clinical presentation of an individual with predisposed genetic susceptibility to hyperlipoproteinemia. The genetic profiles studied are far from complete and there is room for further characterization of genes influencing lipid levels. Genetic assessment can help identify patients at risk for developing dyslipidemias and for treatment decisions based on 'risk allele' profiles. This review will present the current information on the genetics and pathophysiology of disorders that cause dyslipidemias.
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1061 One patient was identified to be homozygous for a nonsense mutation p. Q1038X, a further kindred showed compound heterozygosity for missense variants p. R937V and p.T940M, and a third pedigree was compound heterozygous for a frameshift variant p.I1200Hfs*4 and an intronic variant that lead to the creation of a cryptic splice site and premature truncation p. S1392Rfs*6.
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ABCA1 p.Gln1038* 26546829:1061:71
status: NEW