APOL1 Genotyping

Gene: APOL1

Protein: apolipoprotein L-1

Clinical Characteristics

APOL1 variants are associated with increased susceptibility to focal segmental glomerulosclerosis (FSGS4; OMIM 612551) when two risk alleles are present.

Focal segmental glomerulosclerosis is clinically associated with:

  • Proteinuria
  • Nephrotic syndrome
  • Progressive loss of renal function leading to end-stage renal disease

Individuals of African descent are at a greater risk to develop chronic kidney disease than individuals of European descent. Studies have shown that specific variants in APOL1 confer nearly all of this increased risk. These variants, classified as G1 and G2 are prevalent in African Americans, and have not been identified in European Americans.

APOL1 variants are also associated with increased risk of hypertension-attributed end stage renal disease, sickle cell-associated kidney disease, and shortened graft survival of kidney transplants based on the donor genotype.

Inheritance pattern: Autosomal recessive

What Can Be Learned From This Test

Identification of two risk alleles in one individual is associated with an increased susceptibility to focal segmental glomerulosclerosis and other types of kidney disease.

Some studies indicate that donor kidneys harboring two APOL1 risk variants failed more rapidly after transplantation than those kidneys with zero or one risk variant.

Testing is performed by bi-directional sequencing of exon 6 of APOL1 (NM_145343.2). This test will determine the presence or absence of the G1 and G2 alleles.

Sample Requirements

Draw 2ml–4ml of blood in EDTA/purple-top tube (minimum of 1ml–2ml for infants).

Turnaround time: 10-14 business days

CPT Codes and Cost


Code: 81479

Cost: $225

Known Variant Testing 

Code: 81479

Cost: $225

Additional Information