1
|
Gu R, Wang H, Wang CL, Lu M, Miao M, Huang MN, Chen Y, Dai YL, Zhu MQ, Zhou Q, Zou CC. Gene variants and clinical characteristics of children with sitosterolemia. Lipids Health Dis 2024; 23:83. [PMID: 38509578 PMCID: PMC10953262 DOI: 10.1186/s12944-024-02077-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/12/2024] [Indexed: 03/22/2024] Open
Abstract
OBJECTIVE To enhance the detection, management and monitoring of Chinese children afflicted with sitosterolemia by examining the physical characteristics and genetic makeup of pediatric patients. METHODS In this group, 26 children were diagnosed with sitosterolemia, 24 of whom underwent genetic analysis. Patient family medical history, physical symptoms, tests for liver function, lipid levels, standard blood tests, phytosterol levels, cardiac/carotid artery ultrasounds, fundus examinations, and treatment were collected. RESULTS The majority (19, 73.1%) of the 26 patients exhibited xanthomas as the most prevalent manifestation. The second most common symptoms were joint pain (7, 26.9%) and stunted growth (4, 15.4%). Among the 24 (92.3%) patients whose genetics were analyzed, 16 (66.7%) harbored ABCG5 variants (type 2 sitosterolemia), and nearly one-third (8, 33.3%) harbored ABCG8 variants (type 1 sitosterolemia). Additionally, the most common pathogenic ABCG5 variant was c.1166G > A (p.Arg389His), which was found in 10 patients (66.7%). Further analysis did not indicate any significant differences in pathological traits among those carrying ABCG5 and ABCG8 variations (P > 0.05). Interestingly, there was a greater abundance of nonsense variations in ABCG5 than in ABCG8 (P = 0.09), and a greater frequency of splicing variations in ABCG8 than ABCG5 (P = 0.01). Following a change in diet or a combination of ezetimibe, the levels of cholesterol and low-density lipoprotein were markedly decreased compared to the levels reported before treatment. CONCLUSION Sitosterolemia should be considered for individuals presenting with xanthomas and increased cholesterol levels. Phytosterol testing and genetic analysis are important for early detection. Managing one's diet and taking ezetimibe can well control blood lipids.
Collapse
Affiliation(s)
- Rui Gu
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
- Department of NICU, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Zhejiang, China
| | - Hui Wang
- Department of Rehabilitation, Children's Hospital of Zhejiang University School of Medicine, Zhejiang, China
| | - Chun-Lin Wang
- Department of Pediatrics, The First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang, China
| | - Mei Lu
- Department of Pediatrics, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, China
| | - Miao Miao
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
| | - Meng-Na Huang
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
| | - Yi Chen
- Department of Pulmonology, Children's Hospital of Zhejiang University School of Medicine, Zhejiang, Hangzhou, China
| | - Yang-Li Dai
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
| | - Ming-Qiang Zhu
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
| | - Qiong Zhou
- Department of Pediatrics, Hangzhou Children's Hospital, Hangzhou, 310005, China
| | - Chao-Chun Zou
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China.
| |
Collapse
|
2
|
Wang Y, Guo YL, Dong QT, Li JJ. Severe aortic valve stenosis in a 14-year-old boy with sitosterolemia. J Clin Lipidol 2019; 13:49-53. [PMID: 30528907 DOI: 10.1016/j.jacl.2018.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 11/08/2018] [Accepted: 11/08/2018] [Indexed: 10/27/2022]
|
3
|
Abstract
PURPOSE OF REVIEW To provide an update on recent advances made in our mechanistic and pathophysiological understanding of the rare human disease Sitosterolemia, the role of ABCG5/ABCG8 in sterol trafficking and how newer data implicate a more wider role in the body. RECENT FINDINGS Sitosterolemia is caused by a genetic defect of sterolins (ABCG5/ABCG8) mapped to the STSL locus. Polymorphic variations in STSL have been linked to lipid levels and gallstone disease in whites. Newer studies now link this locus to a more diverse ethnic group for gallstone disease, susceptibility to biliary cancer, and show variants that alter sterolin function. Intriguingly, carriers of a mutant allele seem to show protection against carotid wall disease. Although the 'promoter' region of the STSL is minimal, regulatory regions responsive to liver X receptor have remained elusive, but no longer; two intronic regions in ABCG8 have now been identified. Xenosterol accumulation leads to loss of abdominal fat, infertility, and premature death. Xenosterol accumulation in mouse platelet membranes leads to platelet hyperactivation, increased microparticle formation, and reduced αIIbβ3 surface expression. In humans, phytosterols may promote liver injury in parenteral nutrition-associated liver disease. SUMMARY Progress in understanding sterolin function is beginning to show that xenosterols can be toxic and are involved on pathogenesis, and the role of ABCG5/ABCG8 may extend into other metabolic processes by altering intracellular sterol metabolism.
Collapse
Affiliation(s)
- Shailendra B Patel
- aClement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, USA bDivision of Endocrinology, Metabolism and Clinical Nutrition, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| |
Collapse
|
4
|
Escolà-Gil JC, Quesada H, Julve J, Martín-Campos JM, Cedó L, Blanco-Vaca F. Sitosterolemia: Diagnosis, Investigation, and Management. Curr Atheroscler Rep 2014; 16:424. [DOI: 10.1007/s11883-014-0424-2] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
5
|
Horenstein RB, Mitchell BD, Post WS, Lütjohann D, von Bergmann K, Ryan KA, Terrin M, Shuldiner AR, Steinle NI. The ABCG8 G574R variant, serum plant sterol levels, and cardiovascular disease risk in the Old Order Amish. Arterioscler Thromb Vasc Biol 2012; 33:413-9. [PMID: 23241408 DOI: 10.1161/atvbaha.112.245480] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To determine whether long-term exposure to moderate elevations in plasma plant sterol levels increases risk for atherosclerosis. METHODS AND RESULTS In Old Order Amish participants aged 18 to 85 years, with (n=110) and without (n=181) 1 copy of the ABCG8 G574R variant, we compared mean plasma levels of plant sterols and cholesterol precursors and carotid intima-media wall thickness. Carriers of a single 574R allele had increased plant sterol levels (eg, 35%-37% higher plasma levels of sitosterol, campesterol, and stigmasterol) and increased plant sterol/cholesterol ratios (P<0.001 for all). 574R carriers had significantly decreased levels of lathosterol and lanosterol, precursors in a pathway for endogenous cholesterol synthesis, suggesting that plant sterols may alter regulation of genes involved in cholesterol synthesis. The G574R variant was not associated with high-density lipoprotein cholesterol or low-density lipoprotein cholesterol levels. Compared with noncarriers, 574R carriers had decreased carotid intima-media wall thickness (0.62 versus 0.66 mm; age- and sex-adjusted P=0.03). Adjustment for body weight, blood pressure, and standard lipid measures (high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides) did not alter this association. CONCLUSIONS Although the G574R variant is associated with moderately elevated plant sterol levels, carriers of the 574R allele had modestly lower levels of carotid wall thickness compared with noncarriers.
Collapse
Affiliation(s)
- Richard B Horenstein
- Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Hao DC, Feng Y, Xiao R, Xiao PG. Non-neutral nonsynonymous single nucleotide polymorphisms in human ABC transporters: the first comparison of six prediction methods. Pharmacol Rep 2012; 63:924-34. [PMID: 22001980 DOI: 10.1016/s1734-1140(11)70608-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 02/07/2011] [Indexed: 11/28/2022]
Abstract
Nonsynonymous single nucleotide polymorphisms (nsSNPs) in coding regions that can lead to amino acid changes may cause alteration of protein function and account for susceptibility to disease and altered drug/xenobiotic response. Abundant nsSNPs have been found in genes coding for human ATP-binding cassette (ABC) transporters, but there is little known about the relationship between the genotype and phenotype of nsSNPs in these membrane proteins. In addition, it is unknown which prediction method is better suited for the prediction of non-neutral nsSNPs of ABC transporters. We have identified 2,172 validated nsSNPs in 49 human ABC transporter genes from the Ensembl genome database and the NCBI SNP database. Using six different algorithms, 41 to 52% of nsSNPs in ABC transporter genes were predicted to have functional impacts on protein function. Predictions largely agreed with the available experimental annotations. Overall, 78.5% of non-neutral nsSNPs were predicted correctly as damaging by SNAP, which together with SIFT and PolyPhen, was superior to the prediction methods Pmut, PhD-SNP, and Panther. This study also identified any amino acids that were likely to be functionally critical but have not yet been studied experimentally. There was significant concordance between the predicted results of SIFT and PolyPhen. Evolutionarily non-neutral (destabilizing) amino acid substitutions are predicted to be the basis for the pathogenic alteration of ABC transporter activity that is associated with disease susceptibility and altered drug/xenobiotic response.
Collapse
Affiliation(s)
- Da Cheng Hao
- Laboratory of Biotechnology, College of Environment, Dalian Jiaotong University, Dalian 116028, China.
| | | | | | | |
Collapse
|
7
|
Phytosterols and phytosterolemia: gene-diet interactions. GENES AND NUTRITION 2010; 6:17-26. [PMID: 21437027 DOI: 10.1007/s12263-010-0182-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Accepted: 08/14/2010] [Indexed: 01/08/2023]
Abstract
Phytosterol intake is recommended as an adjunctive therapy for hypercholesterolemia, and plant sterols/stanols can reduce cholesterol absorption at the intestinal lumen through the Niemann-Pick C1 Like 1 (NPC1L1) transporter pathway by competitive solubilization in mixed micelles. Phytosterol absorption is of less magnitude than cholesterol and is preferably secreted in the intestinal lumen by ABCG5/G8 transporters. Therefore, plasma levels of plant sterols/stanols are negligible compared with cholesterol, under an ordinary diet. The mechanisms of cholesterol and plant sterols absorption and the whole-body pool of sterols are discussed in this chapter. There is controversy about treatment with statins inducing further increase in plasma non-cholesterol sterols raising concerns about the safety of supplementation of plant sterols to such drugs. In addition, increase in plant sterols has also been reported upon consumption of plant sterol-enriched foods, regardless of other treatments. Rare mutations on ABCG5/G8 transporters affecting cholesterol/non-cholesterol extrusion, causing sitosterolemia with xanthomas and premature atheroslerotic disease are now known, and cholesterol/plant sterols absorption inhibitor, ezetimibe, emerges as the drug that reduces phytosterolemia and promotes xanthoma regression. On the other hand, common polymorphisms affecting the NPC1L1 transporter can interfere with the action of ezetimibe. Gene-diet interactions participate in this intricate network modulating the expression of genetic variants on specific phenotypes and can also affect the individual response to the hypolipidemic treatment. These very interesting aspects promoted a great deal of research in the field.
Collapse
|
8
|
Musliner T, Cselovszky D, Sirah W, McCrary Sisk C, Sapre A, Salen G, Lütjohann D, von Bergmann K. Efficacy and safety of ezetimibe 40 mg vs. ezetimibe 10 mg in the treatment of patients with homozygous sitosterolaemia. Int J Clin Pract 2008; 62:995-1000. [PMID: 18484971 DOI: 10.1111/j.1742-1241.2008.01786.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVE To assess the effect of ezetimibe (EZE) 40 mg/day on non-cholesterol sterol plasma concentrations in patients with homozygous sitosterolaemia (HoS). METHODS This was a multi-centre, randomised, double-blind, placebo-controlled parallel group study. Twenty-seven patients (> or = 18 years) with HoS and plasma sitosterol levels > 5 mg/dl who had been taking EZE 10 mg/day for > or = 6 months prior to enrolment received open-label EZE 10 mg/day for the duration of the study and were randomised 1 : 1 to blinded EZE 30 mg/day (4 x EZE 10 mg tablets; n = 13) or placebo (1 x EZE 10 mg tablet and 3 x matching placebo tablets; n = 14) for 26 weeks. Patients were permitted to remain on other ongoing treatments (e.g. bile salt-binding resin, statin and/or low sterol diet). End-points included median per cent between-group changes from baseline in plasma sitosterol, campesterol, lathosterol, low-density lipoprotein (LDL) sterols, LDL cholesterol (LDL-C) measured by gas-liquid chromatography, and Achilles tendon thickness size measured radiographically. RESULTS Ezetimibe 40 mg/day resulted in median per cent changes from baseline in plasma sitosterol levels of 3.3% vs. -10% in the EZE 10 mg/day group, in plasma campesterol of -0.5% vs. -9.7% in the EZE 10 mg/day group, and in plasma lathosterol of 0.8% vs. 1.1% in the EZE 10 mg/day group (p = ns for all between-group differences). Median per cent changes in the EZE 40 mg/day and EZE 10 mg/day groups, respectively, were 1.3% and 0% for LDL sterols and 2.5% and 4.4% for LDL-C (p = ns for both between-group differences). At study end-point, Achilles tendon thickness remained unchanged in the EZE 40 mg/day group and increased slightly in the EZE 10 mg/day group (2.2%), yielding a non-significant between-group difference of -2.2%. EZE 40 mg/day was generally well tolerated. CONCLUSIONS In patients with HoS, treatment with EZE 40 mg/day for 26 weeks was no more effective at reducing plasma plant sterol concentrations vs. EZE 10 mg/day. EZE 40 mg/day had a safety and tolerability profile similar to EZE 10 mg/day.
Collapse
Affiliation(s)
- T Musliner
- Merck Research Laboratories, Rahway, NJ, USA.
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Salen G, Starc T, Sisk CM, Patel SB. Intestinal cholesterol absorption inhibitor ezetimibe added to cholestyramine for sitosterolemia and xanthomatosis. Gastroenterology 2006; 130:1853-7. [PMID: 16697747 DOI: 10.1053/j.gastro.2006.02.027] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2005] [Accepted: 02/01/2006] [Indexed: 12/02/2022]
Abstract
Sitosterolemia is a rare, recessively inherited disorder characterized by increased absorption and delayed removal of noncholesterol sterols, which is associated with accelerated atherosclerosis, premature coronary artery disease, hemolysis, and xanthomatosis. Treatments include low-sterol diet and bile salt-binding resins; however, these often do not reduce the xanthomatosis. We examined the effects of the intestinal cholesterol/phytosterol transporter inhibitor ezetimibe added to cholestyramine in a young female patient with sitosterolemia and associated xanthomatosis. The patient was an 11-year-old female with sitosterolemia presenting with prominent xanthomas in the subcutaneous tissue of both elbows who was receiving treatment with cholestyramine 2 g once daily. Bilateral carotid bruits were audible, and a grade II/VI systolic murmur was detected at the left upper sternal border. She also had a low platelet count of 111,000/microL. Ezetimibe 10 mg once daily was added to the patient's ongoing cholestyramine regimen, and she was evaluated for 1 year. The patient followed an unrestricted diet during the 1-year treatment period. After 1 year of treatment with ezetimibe added to ongoing cholestyramine therapy, the patient's plasma sitosterol and campesterol levels decreased by approximately 50%. Her carotid bruits completely resolved, her systolic murmur diminished, and her platelet count rose to 268,000/microL. More remarkably, the tuberous xanthomas on her elbows had completely regressed. Ezetimibe added to ongoing low-dose cholestyramine therapy led to a marked improvement in plasma sterol concentrations, complete regression of xanthomatosis, resolution of carotid bruits, and improvement in cardiac murmur in a young female patient with sitosterolemia.
Collapse
Affiliation(s)
- Gerald Salen
- Department of Medicine, UMD-New Jersey Medical School, Newark, New Jersey; Veterans Affairs Medical Center, East Orange, New Jersey, USA.
| | | | | | | |
Collapse
|