J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website http://www.jocmr.org

Case Report

Volume 8, Number 10, October 2016, pages 764-767

An Overlapping Case of Alport Syndrome and Thin Basement Membrane Disease

Figure 1. Electron microscopy showing significant segmental glomerular basement membrane thinning alternating with segmental thickening and lamellations suggestive of Alport syndrome.

Figure 2. Preserved linear alpha-5 staining of the glomerular basement membranes, Bowman’s capsule and distal tubular basement membranes suggestive of normal architecture or thin basement membrane disease.

**Table 1.** Alport Syndrome and Thin Basement Membrane Comparison
	Alport syndrome	Thin basement membrane disease
Presentation	Hematuria, proteinuria, renal failure, ocular deficits, and hearing deficits	Hematuria, and occasional mild proteinuria
Prevalence	1 in 50,000 live births	1 in 11 - 19 live births
Biopsy finding	Thickening, fraying, and lamination of the glomerular basement membrane	Thinning of glomerular basement membrane from 300 - 400 nm in normal subjects to 150 - 225 nm
Genetics	Mutation in type IV collagen genes	Mutation in type IV collagen genes
Inheritance pattern	Mostly X-linked	Mostly autosomal dominant
Prognosis	Poor due to development of end stage kidney disease	Good due to the hematuria being mostly benign
Treatment	Based on manifestations including: ACE inhibitors for proteinuria, renal transplantation for end stage kidney disease, and routine treatment for hypertension, sensorineural hearing loss and ocular abnormalities	No treatment required generally

Table 1. Alport Syndrome and Thin Basement Membrane Comparison

Alport syndrome

Thin basement membrane disease

Presentation

Hematuria, proteinuria, renal failure, ocular deficits, and hearing deficits

Hematuria, and occasional mild proteinuria

Prevalence

1 in 50,000 live births

1 in 11 - 19 live births

Biopsy finding

Thickening, fraying, and lamination of the glomerular basement membrane

Thinning of glomerular basement membrane from 300 - 400 nm in normal subjects to 150 - 225 nm

Genetics

Mutation in type IV collagen genes

Inheritance pattern

Mostly X-linked

Mostly autosomal dominant

Prognosis

Poor due to development of end stage kidney disease

Good due to the hematuria being mostly benign

Treatment

Based on manifestations including: ACE inhibitors for proteinuria, renal transplantation for end stage kidney disease, and routine treatment for hypertension, sensorineural hearing loss and ocular abnormalities

No treatment required generally

**Table 2.** Staining for Alpha-3 and Alpha-5 Chains of Collagen IV in Thin Basement Membrane Disease (TBMD) and Alport Syndrome Variants
	Alpha-3 chain of collagen IV	Alpha-5 chain of collagen IV
GBM: glomerular basement membrane; BC: Bowman capsule; TBM: distal tubular basement membrane; EBM: epidermal basement membrane. “Discont” indicated a mosaic pattern or discontinued staining. Infrequent exceptions have been noted on renal biopsies for BC, TBM, and EBM in autosomal recessive Alport variants [1, 2]. Reproduced from Reference [13].
Normal/TBMD	+	+	+	+	+	+	+
Alport variants
X-linked carrier	Discont	Discont	Discont	Discont	Discont	Discont	Discont
X-linked male	-	-	-	-	-	-	-
Autosomal recessive	-	-	-	-	+	+	+

Table 2. Staining for Alpha-3 and Alpha-5 Chains of Collagen IV in Thin Basement Membrane Disease (TBMD) and Alport Syndrome Variants

Alpha-3 chain of collagen IV

Alpha-5 chain of collagen IV

GBM

TBM

GBM

TBM

EBM

GBM: glomerular basement membrane; BC: Bowman capsule; TBM: distal tubular basement membrane; EBM: epidermal basement membrane. “Discont” indicated a mosaic pattern or discontinued staining. Infrequent exceptions have been noted on renal biopsies for BC, TBM, and EBM in autosomal recessive Alport variants [1, 2]. Reproduced from Reference [13].

Normal/TBMD

Alport variants

X-linked carrier

Discont

X-linked male

Autosomal recessive