- Stage 5 chronic kidney disease (HP:0003774): A degree of kidney failure severe enough to require dialysis or kidney transplantation for survival characterized by a severe reduction in glomerular filtration rate (less than 15 ml/min/1.73 m2) and other manifestations including increased serum creatinine. Evidence: PCS. Frequency: 2/2. Onset: Childhood onset (HP:0011463). (PMID:29058690)
- Autosomal recessive inheritance (HP:0000007): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: PCS. (PMID:29058690)
- Podocyte foot process effacement (HP:0031266): An anomaly of podocyte morphology characterized by the loss of the interdigitating foot process pattern (generally called foot process effacement; FPE). The term FPE designates the loss of the usual interdigitating pattern of foot processes of neighboring podocytes, leading to relatively broad expanses of podocyte processes covering the glomerular basement membrane (GBM). It is widely viewed as a pathological derangement that is associated with leakage of macromolecules such as albumin through the glomerular filtration barrier. Evidence: PCS. (PMID:29058690)
- Diffuse mesangial sclerosis (HP:0001967): Thickening and scarring (sclerosis) of the mesangium (a structure in the glomerulus). The sclerosis affects a large portion of the mesangium across multiple glomeruli. Histologic features include an increase in the mesangial matrix, thickened glomerular basement membrane, tubular casts, and interstitial inflammation. Diffuse mesangial sclerosis presents with nephrotic syndrome at birth or within the first year of life. Glomeruli are small and condensed in appearance, with early lesions showing increased loose mesangial collagen that progress to sclerosis with dense collagen without hypercellularity. Podocytes do not show hyperplasia but may be immature and cobblestone-like. Electron microscopy shows extensive foot process effacement without deposits, but increased collagen within mesangial areas. Evidence: PCS. Frequency: 2/2. (PMID:29058690)
- Steroid-resistant nephrotic syndrome (HP:0012588): A form of nephrotic syndrome that does not respond to treatment with steroid medication, defined as persistent proteinuria despite 60mg/m2 or 2mg/kg for 8 weeks, after insuring no infection or non-adherence to medication. Evidence: PCS. Frequency: 2/2. Onset: Infantile onset (HP:0003593). (PMID:29058690)
These phenotypes are associated with the disease nephrotic syndrome, type 21 (OMIM:618594).