No abstract

Kearns-Sayre syndrome is characterized by onset before 20 years, chronic progressive external opthalmoplegia, pigmentary retinal degeneration, and ataxia (and/or hearth block, and/or high protein content in the cerebrospinal fluid) in the presence of mtDNA rearrangements. Multiple endocrine dysfunction associated with this syndrome was rarely reported. In this paper, the Authors report on a female patient with Kearns-Sayre syndrome with large heteroplasmic mtDNA deletion, absence of cytochrome c oxidase in many muscle fibers, partial GH deficiency, hypothyroidism and subsequently insulin dependent diabetes mellitus (IDDM). Anti-thyroid peroxidase and antithyreoglobulin antibodies were present in high titer in serum while anti-islet cell antibodies were absent. The patient developed thyroiditis with Hashimoto encephalopathy. The presence of GH deficiency, autoimmune thyroiditis with hypothyroidism and IDDM distinguishes this case from others and confirms the association of Kearns-Sayre syndrome with multiple endocrine dysfunction. Hashimoto encephalopathy and anti-thyroideal antibodies suggest that in this patient, predisposed by a genetic factor (a mitochondrial deletion) anti-thyroideal antibodies may have contributed to the hypothyroidism and, by interfering with cerebral mitochondrial function, may have caused the encephalopathy. GH deficiency and IDDM can be attributed to oxidative phosphorylation deficiency but the autoimmunity may also have played a role in the production of glandular insufficiencies. It seems important to search for endocrine autoimmunity in every case of KSS.

The Authors investigate the relationship between serum anti-tTG antibodies and EEG pattern in 12 celiac patients of various age on gluten-free diet for 1-10 years. In a group of 6 patients with good compliance with the diet, anti-tTG antibodies were normal in all and EEG in 5; in another group of 6 patients with poor compliance with the diet, serum anti-tTG antibodies were raised in all; EEG abnormalities of various gravity were reported in 5 patients. The concomitance of raised anti-tTG antibodies and EEG abnormalities is stressed, as possible expression of an immune-inflammatory reaction persistent in Central Nervous System.

The sea anemones (Cnidaria) produce neurotoxins, polypeptides active on voltage-gated sodium channels, which induce a non-inactivating condition, with consequent seizures and paralysis in zebrafish (Danio rerio). In humans, severe myoclonic epilepsy of infancy (SMEI) is due to SCN1A gene mutation, which causes a non-inactivating sodium channels condition with seizures. Some symptoms, such as age of first seizure, repetitive events, frequent status epilepticus, scarce responsiveness to antiepileptic drugs (AEDs), may be due to superimposed environmental causes. The authors report a case of SMEI treated for years with benzodiazepines and subsequently with valproate. The attenuation of the frequency of epileptic events and of time in seizing, but no change in burst duration and EEG events was observed. These results are similar to those reported in the literature about zebrafish scn1Lab mutant, which recapitulates the SCN1A symptoms and AED resistance occurring in humans. During seizures the production of polypeptides similar to sea anemones neurotoxins, causing repetitive seizures, status epilepticus, and AED resistance can be hypothesized in subjects with SCN1A mutation.

The Authors report on a patient with Kearns-Sayre syndrome, large mtDNA deletion (7/kb), facial abnormalities and severe central nervous system (CNS) white matter radiological features, commonly attributed to spongy alterations. The common origin from neural crest cell (NCC) of facial structures (cartilagineous, osseous, vascular and of the peripheral nervous system) and of peripheral glia and partially of the CNS white matter are underlined and the facial and glial abnormalities are attributed to the abnormal reproduction/migration of NCC. In this view, the CNS spongy alterations in KSS may be not only a dystrophic process (leukodystrophy) but also a dysplastic condition (leukodysplasia). The Authors hypothesize that the symptoms may be related to mtDNA mutations associated to NCC nuclear gene abnormality.