a. pedigrees of twelve families with heterozygous NEK8 variants. Solid symbols indicate affected individual with kidney disease. Arrow indicates proband. +/− indicates presence of heterozygous NEK8 variant. −/− indicate biallelic wildtype NEK8. Roman numerals indicate generation. MZ = monozygotic; d. death. b. MRI images of proband of Family 3 at age 16: enlarged kidney with multiple cysts, total kidney volume 1300 ml. c-d. Ultrasound of proband of Family 8: enlarged kidneys with extensive bilateral kidney cysts. At age 2 right kidney measured 13.6 cm and left kidney measured 13.3 cm (c), at age 7 right kidney: 17.5 cm and left kidney: 17.7 cm (d). e-g. CT analysis of Family 9: bilaterally enlarged kidneys with cysts. e. CT at 48 years of II-2, who is mosaic for the NEK8 variant, f-g. CT of proband IV-1 at 23 months (f) and at 5 years old (g). h. Pathology images of right kidney of proband of Family 4 at age 5 (20 x 11 x 10 cm, 1488 grams). i. Pathology images of right kidney of proband of Family 8 at 7 years old. j. Pathology images of left kidney of proband of Family 12 at age 4 (18 x 8 x 9.5 cm). k. Hematoxylin and eosin stain of proband of Family 8 showed multiple larger tubular cysts, with glomerular cysts also noted. l. Hematoxylin and eosin stain of proband of Family 12 shows multiple cysts both glomerular and tubular. Below the capsule cysts are smaller and they are larger at the corticomedullary junction. Some fibrosis is seen towards the medulla.