Timely diagnosis of sitosterolemia by next generation sequencing in two children with severe hypercholesterolemia


      • Two hypercholesterolemic children suspected to be autosomal dominant hypercholesterolemia (ADH) homozygotes are described.
      • Targeted Next Generation Sequencing was used for molecular diagnosis.
      • Patients were compound heterozygous for nonsense mutations in ABCG5/G8 genes.
      • Sitosterolemia was confirmed by high plasma levels of phytosterols.
      • Plasma cholesterol level was normalized by dietary and ezetimibe treatment.


      Background and aims

      Severe hypercholesterolemia associated or not with xanthomas in a child may suggest the diagnosis of homozygous autosomal dominant hypercholesterolemia (ADH), autosomal recessive hypercholesterolemia (ARH) or sitosterolemia, depending on the transmission of hypercholesterolemia in the patient's family. Sitosterolemia is a recessive disorder characterized by high plasma levels of cholesterol and plant sterols due to mutations in the ABCG5 or the ABCG8 gene, leading to a loss of function of the ATP-binding cassette (ABC) heterodimer transporter G5-G8.


      We aimed to perform the molecular characterization of two children with severe primary hypercholesterolemia.


      Case #1 was a 2 year-old girl with high LDL-cholesterol (690 mg/dl) and tuberous and intertriginous xanthomas. Case #2 was a 7 year-old boy with elevated LDL-C (432 mg/dl) but no xanthomas. In both cases, at least one parent had elevated LDL-cholesterol levels. For the molecular diagnosis, we applied targeted next generation sequencing (NGS), which unexpectedly revealed that both patients were compound heterozygous for nonsense mutations: Case #1 in ABCG5 gene [p.(Gln251*)/p.(Arg446*)] and Case #2 in ABCG8 gene [p.(Ser107*)/p.(Trp361*)]. Both children had extremely high serum sitosterol and campesterol levels, thus confirming the diagnosis of sisterolemia. A low-fat/low-sterol diet was promptly adopted with and without the addition of ezetimibe for Case #1 and Case #2, respectively. In both patients, serum total and LDL-cholesterol decreased dramatically in two months and progressively normalized.


      Targeted NGS allows the rapid diagnosis of sitosterolemia in children with severe hypercholesterolemia, even though their family history does not unequivocally suggest a recessive transmission of hypercholesterolemia. A timely diagnosis is crucial to avoid delays in treatment.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Atherosclerosis
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Cuchel M.
        • Bruckert E.
        • Ginsberg H.N.
        • Raal F.J.
        • Santos R.D.
        • Hegele R.A.
        • et al.
        European atherosclerosis society consensus panel on familial hypercholesterolaemia. Homozygous familial hypercholesterolaemia: new insights and guidance for clinicians to improve detection and clinical management. A position paper from the consensus panel on familial hypercholesterolaemia of the European atherosclerosis society.
        Eur. Heart J. 2014; 35: 2146-2157
        • Bertolini S.
        • Pisciotta L.
        • Rabacchi C.
        • Cefalù A.B.
        • Noto D.
        • Fasano T.
        • et al.
        Spectrum of mutations and phenotypic expression in patients with autosomal dominant hypercholesterolemia identified in Italy.
        Atherosclerosis. 2013; 227: 342-348
        • Sjouke B.
        • Kusters D.M.
        • Kindt I.
        • Besseling J.
        • Defesche J.C.
        • Sijbrands E.J.
        • et al.
        Homozygous autosomal dominant hypercholesterolaemia in The Netherlands: prevalence, genotype-phenotype relationship, and clinical outcome.
        Eur. Heart J. 2015; 36: 560-565
        • Sánchez-Hernández R.M.
        • Civeira F.
        • Stef M.
        • Perez-Calahorra S.
        • Almagro F.
        • Plana N.
        • et al.
        Homozygous familial hypercholesterolemia in Spain: prevalence and phenotype-genotype relationship.
        Circ. Cardiovasc Genet. 2016; 9: 504-510
        • Garcia C.K.
        • Wilund K.
        • Arca M.
        • Zuliani G.
        • Fellin R.
        • Maioli M.
        • et al.
        Autosomal recessive hypercholesterolemia caused by mutations in a putative LDL receptor adaptor protein.
        Science. 2001; 292: 1394-1398
        • Soutar A.K.
        • Naoumova R.P.
        • Traub L.M.
        Genetics, clinical phenotype, and molecular cell biology of autosomal recessive hypercholesterolemia.
        Arterioscler. Thromb. Vasc. Biol. 2003; 23: 1963-1970
        • Pisciotta L.
        • Priore Oliva C.
        • Pes G.M.
        • Di Scala L.
        • Bellocchio A.
        • Fresa R.
        • et al.
        Autosomal recessive hypercholesterolemia (ARH) and homozygous familial hypercholesterolemia (FH): a phenotypic comparison.
        Atherosclerosis. 2006; 188: 398-405
        • Ajagbe B.O.
        • Othman R.A.
        • Myrie S.B.
        Plant sterols, stanols, and sitosterolemia.
        J. AOAC Int. 2015; 98: 716-723
        • Yoo E.-G.
        Sitosterolemia: a review and update of pathophysiology, clinical spectrum, diagnosis, and management.
        Ann. Pediatr. Endocrinol. Metab. 2016; 21: 7-14
        • Stitziel N.O.
        • Fouchier S.W.
        • Sjouke B.
        • et al.
        Exome sequencing and directed clinical phenotyping diagnose cholesterol ester storage disease presenting as autosomal recessive hypercholesterolemia.
        Arterioscler. Thromb. Vasc. Biol. 2013 Dec; 33: 2909-2914
        • Burton B.K.
        • Deegan P.B.
        • Enns G.M.
        • Guardamagna O.
        • Horslen S.
        • Hovingh G.K.
        • et al.
        Clinical features of lysosomal acid lipase deficiency.
        J. Pediatr. Gastroenterol. Nutr. 2015; 61: 619-625
        • Chora J.R.
        • Alves A.C.
        • Medeiros A.M.
        • et al.
        Lysosomal acid lipase deficiency: a hidden disease among cohorts of familial hypercholesterolemia?.
        J. Clin. Lipidol. 2017; (in press)
        • Dron J.S.
        • Hegele R.A.
        Genetics of lipid and lipoprotein disorders and traits.
        Curr. Genet. Med. Rep. 2016; 4: 130-141
        • Fellin R.
        • Arca M.
        • Zuliani G.
        • Calandra S.
        • Bertolini S.
        The history of Autosomal Recessive Hypercholesterolemia (ARH). From clinical observations to gene identification.
        Gene. 2015; 555: 23-32
        • Hooper A.J.
        • Bell D.A.
        • Hegele R.A.
        • Burnett J.R.
        Clinical utility gene card for: Sitosterolaemia.
        Eur. J. Hum. Genet. 2017 Apr; 25
        • Niu D.M.
        • Chong K.W.
        • Hsu J.H.
        • Wu T.J.
        • Yu H.C.
        • Huang C.H.
        • et al.
        Clinical observations, molecular genetic analysis, and treatment of sitosterolemia in infants and children.
        J. Inherit. Metab. Dis. 2010; 33: 437-443
        • Park J.H.
        • Chung I.H.
        • Kim D.H.
        • Choi M.H.
        • Garg A.
        • Yoo E.G.
        Sitosterolemia presenting with severe hypercholesterolemia and intertriginous xanthomas in a breastfed infant: case report and brief review.
        J. Clin. Endocrinol. Metab. 2014; 99: 1512-1518
        • Burton B.K.
        • Balwani M.
        • Feillet F.
        • Barić I.
        • Burrow T.A.
        • Camarena Grande C.
        • et al.
        A phase 3 trial of sebelipase Alfa in lysosomal acid lipase deficiency.
        N. Engl. J. Med. 2015; 373: 1010-1020
        • Hansel B.
        • Carrié A.
        • Brun-Druc N.
        • Leclert G.
        • Chantepie S.
        • Coiffard A.S.
        • et al.
        Premature atherosclerosis is not systematic in phytosterolemic patients: severe hypercholesterolemia as a confounding factor in five subjects.
        Atherosclerosis. 2014; 234: 162-168
        • Cacciari E.
        • Milani S.
        • Balsamo A.
        • Spada E.
        • Bona G.
        • Cavallo L.
        • et al.
        Italian cross-sectional growth charts for height, weight and BMI (2 to 20 yr).
        J. Endocrinol. Invest. 2006; 29: 581-593
        • Mannucci L.
        • Guardamagna O.
        • Bertucci P.
        • Pisciotta L.
        • Liberatoscioli L.
        • Bertolini S.
        • et al.
        Beta-sitosterolemia: a new nonsense mutation in the ABCG5 gene.
        Eur. J. Clin. Invest. 2007; 37: 997-1000
        • Yilmaz B.S.
        • Mungan N.O.
        • Di Leo E.
        • Magnolo L.
        • Artuso L.
        • Bernardis I.
        • et al.
        Homozygous familial hypobetalipoproteinemia: a Turkish case carrying a missense mutation in apolipoprotein B.
        Clin. Chim. Acta. 2016; 452: 185-190
        • den Dunnen J.T.
        • Dalgleish R.
        • Maglott D.R.
        • Hart R.K.
        • Greenblatt M.S.
        • McGowan-Jordan J.
        • et al.
        HGVS recommendations for the description of sequence variants: 2016 update.
        Hum. Mutat. 2016; 37: 564-569
        • Huijgen R.
        • Hutten B.A.
        • Kindt I.
        • Vissers M.N.
        • Kastelein J.J.
        Discriminative ability of LDL-cholesterol to identify patients with familial hypercholesterolemia: a cross-sectional study in 26,406 individuals tested for genetic FH.
        Circ. Cardiovasc Genet. 2012; 5: 354-359
        • Fouchier S.W.
        • Hutten B.A.
        • Defesche J.C.
        Current novel-gene-finding strategy for autosomal-dominant hypercholesterolaemia needs refinement.
        J. Med. Genet. 2015; 52: 80-84
        • Hopkins P.N.
        • Defesche J.
        • Fouchier S.W.
        • Bruckert E.
        • Luc G.
        • Cariou B.
        • et al.
        Characterization of autosomal dominant hypercholesterolemia caused by PCSK9 gain of function mutations and its specific treatment with Alirocumab, a PCSK9 monoclonal antibody.
        Circ. Cardiovasc Genet. 2015; 8: 823-831
        • Rabacchi C.
        • Bigazzi F.
        • Puntoni M.
        • Sbrana F.
        • Sampietro T.
        • Tarugi P.
        • Bertolini S.
        • Calandra S.
        Phenotypic variability in 4 homozygous familial hypercholesterolemia siblings compound heterozygous for LDLR mutations.
        J. Clin. Lipidol. 2016; 10: 944-952
        • Kidambi S.
        • Patel S.B.
        Sitosterolaemia: pathophysiology, clinical presentation and laboratory diagnosis.
        J. Clin. Pathol. 2008; 61: 588-594
        • Dionisi-Vici C.
        • Shteyer E.
        • Niceta M.
        • Rizzo C.
        • Pode-shakked B.
        • Chillemi G.
        • et al.
        Expanding the molecular diversity and phenottypic spectrum of glycerol-3-phosphate dehydrogenase 1 deficiency.
        J. Inherit. Metab. Dis. 2016; 39: 689-695
        • Slimani A.
        • Jelassi A.
        • Jguirim I.
        • Najah M.
        • Rebhi L.
        • Omezzine A.
        • et al.
        Effect of mutations in LDLR and PCSK9 genes on phenotypic variability in Tunisian familial hypercholesterolemia patients.
        Atherosclerosis. 2012; 222: 158-166]
        • Dron J.S.
        • Hegele R.A.
        Complexity of mechanisms among human proprotein convertase subtilisin-kexin type 9 variants.
        Curr. Opin. Lipidol. 2017 Apr; 28: 161-169
        • Othman R.A.
        • Myrie S.B.
        • Jones P.J.
        Non-cholesterol sterols and cholesterol metabolism in sitosterolemia.
        Atherosclerosis. 2013; 231: 291-299
        • Rios J.
        • Stein E.
        • Shendure J.
        • Hobbs H.H.
        • Cohen J.C.
        Identification by whole-genome resequencing of gene defect responsible for severe hypercholesterolemia.
        Hum. Mol. Genet. 2010; 19: 4313-4318
        • Tada H.
        • Kawashiri M.A.
        • Takata M.
        • Matsunami K.
        • Imamura A.
        • Matsuyama M.
        • et al.
        Infantile cases of sitosterolaemia with novel mutations in the ABCG5 gene: extreme hypercholesterolaemia is exacerbated by breastfeeding.
        JIMD Rep. 2015; 21: 115-122
        • Tada H.
        • Kawashiri M.
        • Okada H.
        • Endo S.
        • Toyoshima Y.
        • Konno T.
        • et al.
        A rare coincidence of Sitosterolemia and Familial Mediterranean Fever identified by whole exome sequencing.
        J. Atheroscler. Thromb. 2016; 23: 884-890
        • Renner C.
        • Connor W.E.
        • Steiner R.D.
        Sitosterolemia presenting as pseudohomozygous familial hypercholesterolemia.
        Clin. Med. Res. 2016; 14: 103-108
        • Ono S.
        • Matsuda J.
        • Saito A.
        • Yamamoto T.
        • Fujimoto W.
        • Shimizu H.
        • Dateki S.
        • Ouchi K.
        A case of sitosterolemia due to compound heterozygous mutations in ABCG5: clinical features and treatment outcomes obtained with colestimide and ezetimibe.
        Clin. Pediatr. Endocrinol. 2017; 26: 17-23
        • Salen G.
        • Starc T.
        • Sisk C.M.
        • Patel S.B.
        Intestinal cholesterol absorption inhibitor ezetimibe added to cholestyramine for sitosterolemia and xanthomatosis.
        Gastroenterology. 2006; 130: 1853-1857
        • Lütjohann D.
        • von Bergmann K.
        • Sirah W.
        • Macdonell G.
        • Johnson-Levonas A.O.
        • Shah A.
        • et al.
        Long-term efficacy and safety of ezetimibe 10 mg in patients with homozygous sitosterolemia: a 2-year, open-label extension study.
        Int. J. Clin. Pract. 2008; 62: 1499-1510