You are here: Home Team Alexej Knaus

Alexej Knaus


Alexej Knaus 

Research interest

On all eukaryotic cells a specific glycolipid functions as an anchor to attach proteins to the plasma membrane: The glycosylphosphatidylinositol (GPI) anchor. There are more than 150 proteins that are attached to the cell surface via the GPI anchor. It therefore plays important roles in signal transduction, cell adhesion, antigen presentation and complement regulation. So far 29 genes have been identified in the synthesis and maturation of the GPI anchor, and attachment and transport of GPI anchored proteins (GPI-APs). Defects in the synthesis and maturation pathway of the GPI anchor, which lead to reduction of GPI-APs, are a subclass of congenital disorders of glycosylation (CDG). Disease-causing mutations have been described for 17 of these genes. Among the most common features in GPI biosynthesis defects (GPIBDs) are intellectual disability, epilepsies, and elevated alkaline phosphatase activity. However, the expressivity of the clinical features varies from severe syndromic forms with multiple organ malformations to mild non-syndromic intellectual disability. Yet, the pathophysiological implications of GPI deficiencies that lead to the broad phenotypic spectrum are only poorly understood. The objectives of my study are: 1st functional characterization of pathogenic mutations in genes of the GPI synthesis pathway, 2nd investigation of the underlying pathophysiological mechanism of GPI deficiencies, 3rd correct diagnosis of exome data based on facial gestalt recognition and flow cytometry in cases with suspected GPIBDs. 


Scientific Vita

since 2018   Postdoc at the Institute for Genomic Statistics and Bioinformatics, University Bonn, Germany

2014-2018   PhD Student at the Institute for Medical Genetics and Human Genetics, Charité Universitätsmedizin Berlin, Germany
                    Working on GPI anchor deficiencies in the lab of Peter Krawitz.
                    Graduate student at the Berlin Brandenburg School for Regenerative Therapies (BSRT), Berlin, Germany
2013-2014   Business development, support, sales and marketing at GeneTalk GmbH
2012-2013   Master of Science in Molecular Biotechnology at the University of Barcelona and 
                    Center of Regenerative Medicine in Barcelona  CMR[B] in the Izpisua Belmonte lab, Barcelona, Spain 
2007-2012   Bachelor of Science in Molecular Biomedicine at the Rheinische Friedrich-Wilhelms-Universität Bonn, Germany
                    at the Department of Developmental Pathology in the Schorle lab and at the Life&Brain


Characterization of glycosylphosphatidylinositol biosynthesis defects by clinical features, flow cytometry, and automated image analysis.

Knaus A, Pantel JT, Pendziwiat M, Hajjir N, Zhao M, Hsieh TC, Schubach M, Gurovich Y, Fleischer N, Jäger M, Köhler S, Muhle H, Korff C, Møller RS, Bayat A, Calvas P, Chassaing N, Warren H, Skinner S, Louie R, Evers C, Bohn M, Christen HJ, van den Born M, Obersztyn E, Charzewska A, Endziniene M, Kortüm F, Brown N, Robinson PN, Schelhaas HJ, Weber Y, Helbig I, Mundlos S, Horn D, Krawitz PM.

Genome Med. 2018 Jan 9;10(1):3. doi: 10.1186/s13073-017-0510-5. PMID: 29310717


A Novel de novo FZD2 Mutation in a Patient with Autosomal Dominant Omodysplasia.

Türkmen S, Spielmann M, Güneş N, Knaus A, Flöttmann R, Mundlos S, Tüysüz B.

Mol Syndromol. 2017 Nov;8(6):318-324. doi: 10.1159/000479721. Epub 2017 Sep 8. PMID: 29230162


Reduced cell surface levels of GPI-linked markers in a new case with PIGG loss of function.

Zhao JJ, Halvardson J, Knaus A, Georgii-Hemming P, Baeck P, Krawitz PM, Thuresson AC, Feuk L.

Hum Mutat. 2017 Oct;38(10):1394-1401. doi: 10.1002/humu.23268. Epub 2017 Jun 12. PMID: 28581210


Rare Noncoding Mutations Extend the Mutational Spectrum in the PGAP3 Subtype of Hyperphosphatasia with Mental Retardation Syndrome.

Knaus A, Awaya T, Helbig I, Afawi Z, Pendziwiat M, Abu-Rachma J, Thompson MD, Cole DE, Skinner S, Annese F, Canham N, Schweiger MR, Robinson PN, Mundlos S, Kinoshita T, Munnich A, Murakami Y, Horn D, Krawitz PM.

Hum Mutat. 2016 Aug;37(8):737-44. doi: 10.1002/humu.23006. Epub 2016 May 19. PMID: 27120253


A homozygous HOXD13 missense mutation causes a severe form of synpolydactyly with metacarpal to carpal transformation.

Ibrahim DM, Tayebi N, Knaus A, Stiege AC, Sahebzamani A, Hecht J, Mundlos S, Spielmann M.

Am J Med Genet A. 2016 Mar;170(3):615-21. doi: 10.1002/ajmg.a.37464. Epub 2015 Nov 18. PMID: 26581570


Crowdsourced direct-to-consumer genomic analysis of a family quartet.

Corpas M, Valdivia-Granda W, Torres N, Greshake B, Coletta A, Knaus A, Harrison AP, Cariaso M, Moran F, Nielsen F, Swan D, Weiss Solís DY, Krawitz P, Schacherer F, Schols P, Yang H, Borry P, Glusman G, Robinson PN.

BMC Genomics. 2015 Nov 7;16:910. doi: 10.1186/s12864-015-1973-7. PMID: 26547235


FGFR2 mutation in a patient without typical features of Pfeiffer syndrome--The emerging role of combined NGS and phenotype based strategies.

Flöttmann R, Knaus A, Zemojtel T, Robinson PN, Mundlos S, Horn D, Spielmann M.

Eur J Med Genet. 2015 Aug;58(8):376-80. doi: 10.1016/j.ejmg.2015.05.007. Epub 2015 Jun 19. PMID: 26096994


Homozygous and compound-heterozygous mutations in TGDS cause Catel-Manzke syndrome.

Ehmke N, Caliebe A, Koenig R, Kant SG, Stark Z, Cormier-Daire V, Wieczorek D, Gillessen-Kaesbach G, Hoff K, Kawalia A, Thiele H, Altmüller J, Fischer-Zirnsak B, Knaus A, Zhu N, Heinrich V, Huber C, Harabula I, Spielmann M, Horn D, Kornak U, Hecht J, Krawitz PM, Nürnberg P, Siebert R, Manzke H, Mundlos S.

Am J Hum Genet. 2014 Dec 4;95(6):763-70. doi: 10.1016/j.ajhg.2014.11.004. PMID: 25480037

Document Actions