Characteristics of sporadic Creutzfeldt-Jakob disease cases in Malta

Abstract

Introduction: Creutzfeldt-Jakob disease (CJD) can be one of three forms: sporadic, acquired or genetic due to DNA variations in the PRPN gene. A total of 12 cases of sporadic CJD have been diagnosed between 2012 and 2017. The annual mortality rate has been calculated as 4.69/million, which is considerably high when compared to countries such as the UK (1.59/million). Methods: Extensive review of patient’s clinical records, including electronic patient data was conducted in order to establish possible epidemiological links, clinical data and relevant diagnostic criteria for CJD. Results: Seven of those affected were men with a mean age of onset at 66.7 years. Illness duration was of 1 month for the largest proportion of patients (n=5), and the longest was 8 months. Mean duration of illness was 2.7 months. Of all those affected, only 3 could be diagnosed as having definite CJD, the rest classified as probable CJD using CDC criteria for classification. Successful lumbar puncture on 3 patients tested positive for protein 14-3-3. Only 3 patients had no history of surgical procedures. Nearly all the patients (n=11) experienced myoclonic jerks and EEG confirmed the diagnosis in all those who had an EEG performed (n=10). Molecular genetic testing for the PRPN gene was done on 6 of the cases and this revealed the same heterozygous c.628G>A mutation in 4 patients. Conclusion: No epidemiological link could be established for the cases evaluated. Multi-disciplinary involvement must be encouraged to continue tackling this public health concern and establish aetiology for all CJD cases in Malta.