Fatal outcome due to deficiency of subunit 6 of the conserved oligomeric Golgi complex leading to a new type of congenital disorders of glycosylation

TY - JOUR

T1 - Fatal outcome due to deficiency of subunit 6 of the conserved oligomeric Golgi complex leading to a new type of congenital disorders of glycosylation

AU - Luebbehusen, Juergen

AU - Thiel, Christian

AU - Rind, Nina

AU - Ungar, Daniel

AU - Prinsen, Berthil H. C. M. T.

AU - de Koning, Tom J.

AU - van Hasselt, Peter M.

AU - Koerner, Christian

PY - 2010/9/15

Y1 - 2010/9/15

N2 - Deficiency of subunit 6 of the conserved oligomeric Golgi (COG6) complex causes a new combined N- and O-glycosylation deficiency of the congenital disorders of glycosylation, designated as CDG-IIL (COG6-CDG). The index patient presented with a severe neurologic disease characterized by vitamin K deficiency, vomiting, intractable focal seizures, intracranial bleedings and fatal outcome in early infancy. Analysis of oligosaccharides from serum transferrin by HPLC and mass spectrometry revealed the loss of galactose and sialic acid residues, whereas import and transfer of these sugar residues into Golgi-enriched vesicles or onto proteins, respectively, were normal to slightly reduced. Western blot examinations combined with gel filtration chromatography studies in patient-derived skin fibroblasts showed a severely reduced expression of the mentioned subunit and the occurrence of COG complex fragments at the expense of the integral COG complex. Sequencing of COG6-cDNA and COG6 gene resulted in a homozygous mutation (c.G1646T), leading to amino acid exchange p.G549V in the COG6 protein. Retroviral complementation of the patients' fibroblasts with the wild-type COG6-cDNA led to normalization of the COG complex-depending retrograde protein transport after Brefeldin A treatment, demonstrated by immunofluorescence analysis.

AB - Deficiency of subunit 6 of the conserved oligomeric Golgi (COG6) complex causes a new combined N- and O-glycosylation deficiency of the congenital disorders of glycosylation, designated as CDG-IIL (COG6-CDG). The index patient presented with a severe neurologic disease characterized by vitamin K deficiency, vomiting, intractable focal seizures, intracranial bleedings and fatal outcome in early infancy. Analysis of oligosaccharides from serum transferrin by HPLC and mass spectrometry revealed the loss of galactose and sialic acid residues, whereas import and transfer of these sugar residues into Golgi-enriched vesicles or onto proteins, respectively, were normal to slightly reduced. Western blot examinations combined with gel filtration chromatography studies in patient-derived skin fibroblasts showed a severely reduced expression of the mentioned subunit and the occurrence of COG complex fragments at the expense of the integral COG complex. Sequencing of COG6-cDNA and COG6 gene resulted in a homozygous mutation (c.G1646T), leading to amino acid exchange p.G549V in the COG6 protein. Retroviral complementation of the patients' fibroblasts with the wild-type COG6-cDNA led to normalization of the COG complex-depending retrograde protein transport after Brefeldin A treatment, demonstrated by immunofluorescence analysis.

KW - COG COMPLEX

KW - GLYCOPROTEIN SYNDROME

KW - GDP-FUCOSE

KW - PROTEINS

KW - DIAGNOSIS

KW - TRANSPORT

KW - REVEALS

UR - http://www.scopus.com/inward/record.url?scp=77956096967&partnerID=8YFLogxK

U2 - 10.1093/hmg/ddq278

DO - 10.1093/hmg/ddq278

M3 - Article

C2 - 20605848

VL - 19

SP - 3623

EP - 3633

JO - Human Molecular Genetics

JF - Human Molecular Genetics

IS - 18

M1 - ddq278

ER -