HYPOPARATHYROIDISM AND INSULIN-DEPENDENT DIABETES-MELLITUS IN A PATIENT WITH KEARNS-SAYRE SYNDROME HARBORING A MITOCHONDRIAL-DNA DELETION

We report a 17-year-old girl with short stature, external ophthalmople gia, atypical retinal pigmentary degeneration, sensorineural hearing l oss, and cardiac conduction defect (Kearns-Sayre syndrome), A large-sc ale deletion (6741 base pairs) in mitochondrial DNA was found in her m uscle specimen, She also had insulin-dependent diabetes mellitus (IDDM ). On admission, her plasma glucose level was elevated at 31.0 mmol/l with mild ketoacidosis, and haemoglobinA1c elevated at 16.5%, After im provement of diabetic ketoacidosis, she was placed on insulin 24-30 un its/day despite her small body weight of 25 kg, There was reduced excr etion of urinary C-peptide at 3.97 nmol/day. In addition, she had idio pathic hypoparathyroidism with a serum calcium level of 2.15 mmol/l, p hosphate 1.7 mmol/l, and intact PTH below 10 ng/l. Human leucocyte ass ociated antigen typing showed A24, A26; B54, B61; CW1, CW3; DR8, DR14; DQ1 and DQ3, suggesting that the presence of HLA-A24 and CW3 antigen contributed to the association of IDDM and hypoparathyroidism, similar to Japanese patients with polyglandular autoimmune syndrome, complica ted by hypoparathyroidism and IDDM. We suggest that a genetic linkage, as well as mitochondrial dysfunction, may be responsible for the asso ciation of the two disease states. This is an extremely rare case of K earns-Sayre syndrome, presenting in association with IDDM and idiopath ic hypoparathyroidism.