COL4A1 may be a candidate gene in unexplained familial syndromes with autosomal dominant hematuria, cystic kidney disease, intracranial aneurysms, and muscle cramps.

TMA may be the sole renal complication in SLE and is not usually associated with haemolytic microangiopathic anaemia. In our series renal survival was influenced by the extent and severity of vascular lesions. Despite a frequent association with antiphospholipid antibodies, pathophysiological mechanisms of renal TMA in SLE remain unknown. Renal histology is mandatory for the diagnosis and the prognostic evaluation of renal vasculopathy in SLE.

Renal dysfunction is increasingly recognized as a potential clinical feature of mitochondrial cytopathies such as mitochondrial encephalomyopathy, lacticacidosis and stroke-like episodes (MELAS) syndrome. Five cases of MELAS syndrome with renal involvement from 4 unrelated families are presented in this case series. Three of the 5 patients had a history of maternally-inherited diabetes and/or deafness. Focal and segmental glomerulosclerosis and arteriolar hyaline thickening were the most striking findings on renal biopsy. In addition to clinical presentation with the typical symptoms of MELAS syndrome, genetic testing in these patients identified the A3243G point mutation in the tRNALeu gene of the mitochondrial DNA (mtDNA). The diagnosis of MELAS syndrome was thus considered to be unequivocal. The incidence of kidney disease in MELAS syndrome may be underestimated although a study is required to investigate this hypothesis. As the A3243G mtDNA mutation leads to a progressive adult-onset form of focal segmental glomerulosclerosis (FSGS), screening for the MELAS A3243G mtDNA mutation should therefore be performed especially in patients with maternally-inherited diabetes or hearing loss presenting with FSGS.

Plasma Lp(a) lipoprotein level was determined in chronic renal failure (CRF) patients, 24 before initiation of dialysis, 18 undergoing hemodialysis, and 24 on continuous ambulatory peritoneal dialysis (CAPD). Eighteen healthy subjects were studied as controls. Median of Lp(a) level in both predialysis and dialysis patients was significantly increased: 23.5 mg/dl (range: 0 to 109) and 24.0 mg/dl (range: 1.4 to 90), respectively, as compared to healthy controls: 4.7 mg/dl (range: 1.8 to 27; P less than 0.001). By contrast, the median Lp(a) level in CAPD patients, 2.4 mg/dl (range: 0 to 39.5), was similar to the control group. Whether the CAPD procedure reduces the Lp(a) level in CRF patients has to be established in a prospective study.