Nephrotic syndrome type 21 (NPHS21) is an autosomal recessive renal disorder characterized by onset of kidney dysfunction in the first year of life. Laboratory studies show proteinuria and renal biopsy shows diffuse mesangial sclerosis. The disorder is rapidly progressive and ultimately results in end-stage renal disease. Some patients with variable extrarenal manifestations, such as microcephaly or impaired intellectual development, have been reported, but it is not clear whether these features are consistently part of the phenotype (summary by Rao et al., 2017). (Rao et al. (2017) designated the disorder NPHS25.)
For a general phenotypic description and a discussion of genetic heterogeneity of nephrotic syndrome, see NPHS1 (256300). [from
OMIM]