Endocrine Disorders in Children with Primary Mitochondrial Diseases: Single Center Experience.

Objective: Endocrine abnormalities may be the only clinical manifestation of primary mitochondrial disorders. The aim of this study was to evaluate the endocrinological characteristics of mitochondrial disease (MD) in a cohort from a single center.

Methods: Pediatric patients diagnosed with MD were categorized on the basis of their specific genetic abnormalities. The auxologic data, pubertal development, and, based on their clinical symptoms, hormonal profiles were obtained.

Results: Twelve of the cohort of 26 patients (46%) were female. In 15 (57.6%), the MD was caused by nuclear DNA mutations (nDNA group). Four patients had Leigh syndrome, two patients had Leber’s Hereditary Optic Neuropathy syndrome, two patients had Mitochondrial Encephalopathy Lactic Acidosis and Stroke Like episodes, and one patient had Kearns-Sayre syndrome clinical phenotype. The median age at diagnosis was 2.91 (0.59-16.8) years, and the median age at first endocrine evaluation was 4.62 (1.26-18) years. The mean height standard deviation score (SDS) was -1.34±2.12, and the mean body mass index SDS was -0.82±1.96 for all patients. Of the 26 patients, 6 (23%) had a range of hormonal deficits. Ovarian insufficiency, central adrenal insufficiency, central hypothyroidism, diabetes mellitus, and critical illness-related adrenal insufficiency were all observed. Three of the patients were initially monitored in the endocrine clinic for hormone deficiencies but it was later determined that the hormonal abnormalities were caused by underlying MD.

Conclusion: Individuals diagnosed with MD, particularly those with specific genetic abnormalities, are considered a high-risk group for developing hormonal deficits. Endocrine abnormalities may be one of the primary early warning symptoms for MD.