Coincident idiopathic focal segmental glomerulosclerosis collapsing variant and diabetic nephropathy in an African American homozygous for MYH9 risk variants.

Abstract

Familial clustering of disparate kidney diseases including clinically diagnosed hypertensive and diabetic nephropathy, idiopathic focal segmental glomerulosclerosis, and HIV-associated nephropathy are often observed in African Americans. Admixture mapping recently identified the nonmuscle myosin heavy chain 9 gene (MYH9) as a susceptibility factor strongly associated with several nondiabetic etiologies of end-stage renal disease in African Americans, less strongly with diabetes-associated end-stage renal disease. MYH9-associated nephropathies reside in the spectrum of focal segmental glomerulosclerosis/focal global glomerulosclerosis. The renal histology in proteinuric African Americans homozygous for MYH9 risk variants with longstanding type 2 diabetes mellitus is unknown. We report a case of coincident idiopathic focal segmental glomerulosclerosis collapsing variant and diabetic nephropathy in an African American homozygous for the MYH9 E1 risk haplotype. This case demonstrates that diabetic African Americans with overt proteinuria can have mixed renal lesions, including those in the spectrum of MYH9-associated nephropathy. Careful interpretation of kidney biopsies in proteinuric African Americans with diabetes is necessary to exclude coincident nondiabetic forms of nephropathy, precisely define etiologies of kidney disease, and determine the natural history and treatment response in mixed lesions of diabetes-associated and MYH9-associated kidney disease.

• Authors: Isai Gopalakrishnan, Samy S Iskandar, Pirouz Daeihagh, Jasmin Divers, Carl D Langefeld, Donald W Bowden, Pamela J Hicks, Michael V Rocco, Barry I Freedman
• Journal: Human pathology (Hum Pathol) Vol. 42 Issue 2 Pg. 291-4 (Feb 2011) ISSN: 1532-8392 [Electronic] United States
• PMID: 21074826 (Publication Type: Case Reports, Journal Article, Research Support, N.I.H., Extramural)
• Copyright: Copyright © 2011 Elsevier Inc. All rights reserved.

Chemical References

• MYH9 protein, human
• Molecular Motor Proteins
• Myosin Heavy Chains

Topics

• Black or African American (genetics)
• Aged
• Biopsy
• Diabetic Nephropathies (genetics, pathology)
• Family Health
• Female
• Genetic Predisposition to Disease
• Glomerulosclerosis, Focal Segmental (genetics, pathology)
• Homozygote
• Humans
• Male
• Middle Aged
• Molecular Motor Proteins (metabolism)
• Myosin Heavy Chains (metabolism)
• Proteinuria (genetics, pathology)