ESPE Abstracts

Background: Kearns – Sayre syndrome (KSS) is a rare mitochondropathy. Among chronic progressive external opthalmoplegia, pigmentary retinal degeneration and ataxia that are present in most patients before age of 20 years, a significant proportion of patients also have various endocrine deficiencies.

Case report: We report on a previously healthy boy who presented at the age of 8 years to the endocrine clinic due to short stature (height 116 cm; -2.15 SD, weight 18 kg; -2.2 SD). At the time of presentation he had mild unilateral ptosis, and was a bit clumsy while the rest of his clinical status was unremarkable. Growth hormone (GH) stimulation tests were performed confirming growth hormone deficiency. Before GH treatment introduction brain MRI was performed showing hyperintensities in globus pallidum, thalamus, mesencephalon, pons and cerebellum. Due to brain MRI results additional workup was done revealing pigmented retinitis, external ophtalmoplegia, high levels of lactate and protein in cerebrospinal fluid. Diagnosis of KSS was established and afterward molecularly confirmed in urine sample (large 7.6 kb deletion described in 65% mtDNA). Due to ambiguous literature evidence on GH treatment efficacy in KSS patients as well as potential neurological side effects, parents initially decided not to initiate GH treatment. Over the next two years, neurological symptoms including ophtalmoplegia and ataxia gradually worsened, the boys’ growth velocity decreased significantly and finally, GH treatment was introduced which had a positive effect on growth and no side effects.

Conclusion: KSS is a rare and slow-progressing condition. Despite the fact that the first symptoms appear at a young age, they are usually extremely faint at first, and the diagnosis is made much later. Heart block, the most serious complication of KSS can cause death in some patients even before they are diagnosed. Short stature and GH deficiency can be a part of KSS and are usually evident before the onset of visible neurological symptoms. Early diagnosis is crucial to introduce endocrine treatment, routinely screen for comorbidities that are part of KSS, prevent complications and sudden death, and subsequently improve quality of life.