Pseudoxanthoma elasticum : clinical phenotypes, molecular genetics and putative pathomechanisms

Pseudoxanthoma elasticum (PXE), a prototype of heritable multisystem disorders, is characterised by pathologic mineralisation of connective tissues, with primary clinical manifestations in the skin, eyes and the cardiovascular system. The causative gene was initially identified as ABCC6 which encodes an ABC transporter protein (ABCC6) expressed primarily in the liver and the kidneys. The critical role of ABCC6 in ectopic mineralisation has been confirmed by the development of Abcc6(-/-) knock-out mice which recapitulate the features of connective tissue mineralisation characteristic of PXE. Over 300 distinct loss-of-function mutations representative of over 1000 mutant alleles in ABCC6 have been identified by streamlined mutation detection strategies in this autosomal recessive disease. More recently, missense mutations in the GGCX gene, either in compound heterozygous state or digenic with a recurrent ABCC6 nonsense mutation (p.R1141X), have been identified in patients with PXE-like cutaneous findings and vitamin K-dependent coagulation factor deficiency. GGCX encodes a carboxylase which catalyses gamma-glutamyl carboxylation of coagulation factors as well as of matrix gla protein (MGP) which in fully carboxylated form serves as a systemic inhibitor of pathologic mineralisation. Collectively, these observations suggest the hypothesis that a consequence of loss-of-function mutations in the ABCC6 gene is the reduced vitamin K-dependent gamma-glutamyl carboxylation of MGP, with subsequent connective tissue mineralisation. Further progress in understanding the detailed pathomechanisms of PXE should provide novel strategies to counteract, and perhaps cure, this complex heritable disorder at the genome-environment interface.

Medienart:

E-Artikel

Erscheinungsjahr:

2009

Erschienen:

2009

Enthalten in:

Zur Gesamtaufnahme - volume:18

Enthalten in:

Experimental dermatology - 18(2009), 1 vom: 01. Jan., Seite 1-11

Sprache:

Englisch

Beteiligte Personen:

Li, Qiaoli [VerfasserIn]
Jiang, Qiujie [VerfasserIn]
Pfendner, Ellen [VerfasserIn]
Váradi, András [VerfasserIn]
Uitto, Jouni [VerfasserIn]

Links:

Volltext

Themen:

ABCC6 protein, human
ATP-Binding Cassette Transporters
Abcc6 protein, mouse
Journal Article
Multidrug Resistance-Associated Proteins
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Review

Anmerkungen:

Date Completed 26.03.2009

Date Revised 06.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1111/j.1600-0625.2008.00795.x

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM18491194X