AUTHOR=Gogu Anca Elena , Jianu Dragos Catalin , Parv Florina , Motoc Andrei Gheorghe Marius , Axelerad Any , Stuparu Alina Zorina , Gogu Andreea Alexandra TITLE=Case report: Clinical profile, molecular genetics, and neuroimaging findings presenting in a patient with Kearns-Sayre syndrome associated with inherited thrombophilia JOURNAL=Frontiers in Neurology VOLUME=Volume 14 - 2023 YEAR=2024 URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2023.1320757 DOI=10.3389/fneur.2023.1320757 ISSN=1664-2295 ABSTRACT=Background: Kearns-Sayre Syndrome (KSS) is classified as one of the mitochondrial DNA (mtDNA) deletion syndromes with a multisystemic involvement. Additionally, the negative prognosis is associated with inherited thrombophilia, which includes the presence of homogenous Factor V G1691A Leiden mutation, MTHFR gene polymorphism C677T and A1298C, PAI-1 675 homozygous genotype 5G/5G. Case presentation: This case report presents a 48 years-old man with chronic progressive external ophthalmoplegia, bilateral ptosis, cerebellar ataxia, cardiovascular signs (syncope, dilated cardiomyopathy, cardiac arrest) with electrocardiographic abnormalities (first degree atrioventricular block, major right bundle branch block), endocrine disfunction (short stature, growth hormone insufficiency, primary gonadal insufficiency, hypothyroidism, secondary hyperparathyroidism), molecular genetic tests (MT-TL2 gene) and abnormal MRI brain images, thus leading to the diagnosis of KSS. The patient came back four weeks after the diagnosis in the emergency department with massive bilateral pulmonary embolism with syncope at onset, acute cardiorespiratory failure, deep left femoral-popliteal veins thrombophlebitis and altered neurological status. In the intensive care unit, he received mechanical ventilation through intubation. Significant improvement was seen after two weeks. The patient tested positive for inherited thrombophilia and was discharged in stable conditions on a new treatment with Rivaroxaban 20 mg/day. At six months of follow-up, ECG-Holter monitoring and MRI brain images remained unchanged. However, three months later the patient died suddenly while sleeping at home.The genetic tests performed in KSS patients should also include those for inherited thrombophilia. By detecting these mutations, we can prevent major complications such as cerebral venous sinus thrombosis, coronary accidents or sudden death.