Lipoprotein glomerulopathy is an uncommon kidney disease characterized by proteinuria, progressive kidney failure, and distinctive lipoprotein thrombi in glomerular capillaries (Saito et al., 2006). It mainly affects people of Japanese and Chinese origin; in these populations, it is associated with mutations in the gene that encodes apolipoprotein E (APOE; 107741). The disorder had rarely been described in Caucasians.

C3 glomerulopathy-3 (C3G3) is an autosomal dominant kidney disease characterized by the onset of microscopic or macroscopic hematuria in the first 3 decades of life, followed by variable progression of renal disease. After age 30, about half of patients continue to have episodic hematuria while maintaining normal renal function, whereas the other half develop proteinuria and progressive renal failure or end-stage renal disease. In some cases, renal dysfunction may be triggered or exacerbated by an infectious disease, often an upper respiratory infection or pharyngitis. Some patients may also develop hypertension. Renal biopsy shows glomerular C3 deposition and mesangial proliferation with glomerulonephritis. Membranoproliferative glomerulonephritis (MPGN) may also be observed on renal biopsy. Males tend to have a more severe phenotype than females and are more likely to develop end-stage renal disease, often necessitating dialysis or renal transplant (summary by Athanasiou et al., 2011). For a general description and discussion of genetic heterogeneity of C3G, see C3G1 (609814).

Any IgA glomerulonephritis in which the cause of the disease is a mutation in the SPRY2 gene.

Sphingosine phosphate lyase insufficiency syndrome (SPLIS) is characterized by varying combinations of steroid-resistant nephrotic syndrome (ranging from nonimmune fetal hydrops to adolescent onset), primary adrenal insufficiency (with or without mineralocorticoid deficiency), testicular insufficiency, hypothyroidism, ichthyosis, lymphopenia/immunodeficiency, and neurologic abnormalities that can include developmental delay, regression / progressive neurologic involvement, cranial nerve deficits, and peripheral motor and sensory neuropathy.

Autoimmune interstitial lung, joint, and kidney disease is an autosomal dominant systemic autoimmune disorder characterized by interstitial lung disease, inflammatory arthritis, and immune complex-mediated renal disease. Laboratory studies show high-titer autoantibodies. Symptoms appear in the first 2 decades of life, but there is incomplete penetrance (summary by Watkin et al., 2015).

Nephrotic syndrome type 23 (NPHS23) is an autosomal recessive renal disorder characterized by the onset of proteinuria in the first or second decade of life. The outcome is variable: some patients have normal renal function after many years, whereas others may progress to chronic kidney disease. Renal biopsy shows mesangial hypercellularity, consistent with minimal change disease, focal segmental glomerulosclerosis, and effacement of podocyte foot processes (summary by Solanki et al., 2019). For a general phenotypic description and a discussion of genetic heterogeneity of nephrotic syndrome and FSGS, see NPHS1 (256300).

Cataracts, hearing impairment, nephrotic syndrome, and enterocolitis-2 (CHINE2) is an autosomal recessive syndromic disorder characterized by onset of this constellation of features in infancy, resulting in death in early childhood. Telomeres are shortened, but classic mucocutaneous features of DKCB1 are not typically observed. CHINE2 is due to a ribosomal pseudouridylation defect (Balogh et al., 2020). See also CHINE1 (301108), caused by mutation in the DKC1 gene (300126).