Molecular genetic diagnoses in these families included the following: NPHP (NPHP1, n = 16; NPHP3, n = 2; INVS, n = 2; NPHP4, n = 2; WDR19, n = 2;  BBS12, n = 2;  NPHP13, n = 1; RPGRIP1L, n = 2; TMEM67, n = 1), methylmalonic aciduria with homocysteinemia CblC type (MMACHC, n = 7), FSGS (COQ8B, n = 3; COQ2, n = 2), Alport syndrome (COL4A5, n = 1), ADTKD (UMOD, n = 1), Lowe syndrome (OCRL, n = 1), renal dysplasia (PAX2, n = 2; INF1B, n = 1) and rhabdomyolysis syndrome (LPIN1, n = 1). The gene discussed is RPGRIP1L; the disease is hyperhomocysteinemia.