Renal transplantation between monozygotic twins discordant for unilateral renal agenesis.

CASE REPORT The patient was a 26 year old man who presented with typical symptoms of endstage renal failure in December, 1971. Prior to this he had always been well, though his mother remembered that he had a "chill on the kidneys" at the age of 6 years. The family history was negative for renal disease. He had a twin brother. On examination he was clinically anaemic and uraemric. Blood pressure was 130/80 mm Hg. Blood urea 310 mg%; CO2CP 10 mEq/1, electrolytes otherwise normal; G.F.R. 3.9 ml/minute; Hb 8.3 g%; serum calcium 7.3 mg/o; serum phosphorus 9.4 mg0!0: alkaline phosphatase 7 K.A. units; barium meal and micturating cystogram showed no abnormality; Australia antigen negative; height 5 ft. 8 in.; H L-A type 2, 8, W27. Blood group 0 Rh. Positive. He was treated with a Giordano-Giovanetti diet but without drugs or sodium restriction. An arterio-venous fistula was created surgically to facilitate haemodialysis when required. Witih dietary restriction the blood urea fell to 48 mg%. G.F.R. remained less than 5 ml/minute. His twin was admitted for investigation as to monozygosity, and as a potential kidney donor. Facial similarity was striking, but he was 4 inches taller than his brother. H L-A type 2, 8, W27, blood group 0 Rh. Posit'ive, and identical with his twin to 10 sub-groups. Blood urea 25 mg%; electrolytes normal; G.F.R. 115 ml. per minute. Intravenous pyelogram showed 2 normally functioning kidneys; renal arteriogram also showed 2 normal kidneys with vasculature suitable for transplantation; M.S.S.U. was sterile and contained no protein or abnormal elements. Pre-transplant nephrectomy was carried out on the uraemic twin on 25th May, 1972. The right kidney was found to be absent, and the left small and scarred.