NPHS2 variation in sporadic focal segmental glomerulosclerosis.
Mutations in NPHS2, the gene that encodes podocin, are well-established causes of both familial and sporadic steroid-resistant focal segmental glomerulosclerosis (FSGS) in the pediatric population, but have not been well-characterized in late-onset disease. To investigate the role of NPHS2 polymorphisms in sporadic cases of late-onset FSGS, we studied 377 biopsy-confirmed FSGS cases and 919 controls. We identified 18 single nucleotide polymorphisms (SNPs) by resequencing a subgroup of cases and controls, and subsequently genotyped African-American and European-American cases and controls for five missense SNPs, three SNPs within introns, and four SNPs in the 3' untranslated region. No homozygotes or compound heterozygotes were observed for any missense mutation. R138Q carriers were more frequent among FSGS cases relative to controls (OR = 4.9, P = 0.06), but heterozygosity for the other four missense mutations was equally distributed among FSGS cases and controls. Finally, a common haplotype of noncoding SNPs carried by 20% of African-Americans, but not observed in European-Americans, was strongly associated with a 50% reduction in risk for sporadic FSGS (OR = 0.5, P = 0.001). These results indicate that genetic variation or mutation of NPHS2 may play a role in late-onset sporadic FSGS.
McKenzie
Louise M
LM
Laboratory of Genomic Diversity, SAIC-Frederick, National Cancer Institute, NCI-Frederick, Frederick, Maryland, USA.
Hendrickson
Sher L
SL
Briggs
William A
WA
Dart
Richard A
RA
Korbet
Stephen M
SM
Mokrzycki
Michelle H
MH
Kimmel
Paul L
PL
Ahuja
Tejinder S
TS
Berns
Jeffrey S
JS
Simon
Eric E
EE
Smith
Michael C
MC
Trachtman
Howard
H
Michel
Donna M
DM
Schelling
Jeffrey R
JR
Cho
Monique
M
Zhou
Yu C
YC
Binns-Roemer
Elizabeth
E
Kirk
Gregory D
GD
Kopp
Jeffrey B
JB
Winkler
Cheryl A
CA
D016263:AIDS-Associated Nephropathy / Q000208:ethnology / Q000235:genetics* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D001741:Black or African American / Q000235:genetics; D017668:Age of Onset; D016022:Case-Control Studies; D002648:Child; D005838:Genotype; D005923:Glomerulosclerosis, Focal Segmental / Q000208:ethnology / Q000235:genetics* / Q000473:pathology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics*; D020125:Mutation, Missense / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D044465:White People / Q000235:genetics
D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C407223:NPHS2 protein