Analysis of the CTNS gene in patients of German and Swiss origin with nephropathic cystinosis.
The autosomal recessive lysosomal storage disorder, nephropathic cystinosis is characterized by impaired transport of free cystine out of lysosomes. The gene responsible for cystinosis, CTNS, consists of 12 exons and encodes a 55 kDa putative lysosomal membrane protein, called cystinosin. Up to now more than 55 different CTNS mutations have been described in cystinosis. We have analyzed the mutation pattern in a population of 40 cystinosis patients from 35 families of German and Swiss origin. CTNS mutations in 68 out of 70 alleles were identified. The common 57-kb deletion accounted for 65% of the alleles. In five patients we found a known GACT deletion at position 18-21. In two patients we identified a nucleotide substitution at codon 339 and one patient showed a CG insertion at position 697-698. In five patients we observed a G insertion at position 926-927. Moreover, five novel mutations including two deletions involving exon 3 (61-61+2delGGT) and exon 6 (280delG), two insertions in exon 6 (292-293insA) and exon 7 (684insCACTT) and one nucleotide substitution in exon 11 (923G>T) have been identified. These data provide a basis for routine molecular diagnosis of cystinosis in the central European population, especially in cystinosis patients of German and Swiss origin.
Institut für Klinische Chemie und Laboratoriumsdiagnostik, Universitätsklinikum Jena, Germany. michael.kiehntopf@med.uni-jena.de
Michael
M
Kiehntopf
Jörg
J
Schickel
Bärbel von der
Bv
Gönne
Hans Georg
HG
Koch
Andrea
A
Superti-Furga
Beat
B
Steinmann
Thomas
T
Deufel
Erik
E
Harms
D000595:Amino Acid Sequence; D026921:Amino Acid Transport Systems, Neutral; D001483:Base Sequence; D015331:Cohort Studies; D003554:Cystinosis / Q000235:genetics*; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004252:DNA Mutational Analysis; D018703:Founder Effect; D017353:Gene Deletion; D005858:Germany; D006023:Glycoproteins; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D017354:Point Mutation; D017384:Sequence Deletion; D013557:Switzerland
D026921:Amino Acid Transport Systems, Neutral; C111445:CTNS protein, human; D006023:Glycoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D004247:DNA