title: Clinical phenotype of APOL1 nephropathy in young relatives of patients with end-stage renal disease.
abstract: BACKGROUND
  Two coding variants--G1 and G2--in the apolipoprotein L-1 (APOL1) gene are associated with increased incidence of end-stage renal disease (ESRD) in the adult African American population. These variants associate with hypertension-attributed renal disease, focal segmental glomerulosclerosis (FSGS), and HIV-associated nephropathy. We hypothesized that as a genetic disease, APOL1 nephropathy has a pediatric phenotype.
  
  
  METHODS
  We investigated the incidence of APOL1 variants in young African Americans with hypertension or FSGS and a family history of ESRD by conducting a case-control study of 93 pediatric and young adult African Americans with hypertension or FSGS to determine the association with APOL1 risk variants, G1, and G2 using custom-made TaqMan-based allelic discrimination assays.
  
  
  RESULTS
  Forty of the 61 cases (66 %) with a family history of kidney disease had two APOL1 risk variants, significantly higher than the prevalence in controls and the general African American population (p < 0.001); 24 of 29 patients with hypertension-attributed kidney disease had two APOL1 risk variants, while none of nine hypertensive patients without kidney disease had more than one risk allele.
  
  
  CONCLUSIONS
  Although it was a small study cohort, our findings strongly suggest for the first time that two APOL1 risk alleles in young hypertensive African Americans with a family history of ESRD are strongly associated with kidney disease.
authors.affiliation: Department of Pediatrics (Pediatric Nephrology), Washington University School of Medicine, 5th Fl MPRB, 660 South Euclid Avenue, Campus Box 8208, St. Louis, MO, 63110, USA.
authors.forename: Elizabeth I
authors.initials: EI
authors.lastname: Anyaegbu
authors.forename: Andrey S
authors.initials: AS
authors.lastname: Shaw
authors.forename: Keith A
authors.initials: KA
authors.lastname: Hruska
authors.forename: Sanjay
authors.initials: S
authors.lastname: Jain
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American / Q000235:genetics; D017668:Age of Onset; D000075944:Apolipoprotein L1; D001053:Apolipoproteins / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D005923:Glomerulosclerosis, Focal Segmental / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*; D040941:Heredity; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*; D008075:Lipoproteins, HDL / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D010641:Phenotype; D012307:Risk Factors; D055815:Young Adult
chemical_list: C108666:APOL1 protein, human; D000075944:Apolipoprotein L1; D001053:Apolipoproteins; D008075:Lipoproteins, HDL