Estimation of the Number of Patients With Mitochondrial Diseases: A Descriptive Study Using a Nationwide Database in Japan

Abstract

Background To provide a better healthcare system for patients with mitochondrial diseases, it is important to understand the basic epidemiology of these conditions, including the number of patients affected. However, little information about them has appeared in Japan to date. Methods To gather data of patients with mitochondrial diseases, we estimated the number of patients with mitochondrial diseases from April 2018 through March 2019 using a national Japanese health care claims database, the National Database (NDB). Further, we calculated the prevalence of patients, and sex ratio, age class, and geographical distribution. Results From April 2018 through March 2019, the number of patients with mitochondrial diseases was 3,629, and the prevalence was 2.9 (95% confidence interval [CI], 2.8–3.0) per 100,000 general population. The ratio of females and males was 53 to 47, and the most frequent age class was 40–49 years old. Tokyo had the greatest number of patients with mitochondrial diseases, at 477, whereas Yamanashi had the fewest, at 13. Kagoshima had the highest prevalence of patients with mitochondrial diseases, 8.4 (95% CI, 7.1–10.0) per 100,000 population, whereas Yamanashi had the lowest, 1.6 (95% CI, 0.8–2.7). Conclusion The number of patients with mitochondrial diseases estimated by this study, 3,269, was more than double that indicated by the Japanese government. This result may imply that about half of all patients are overlooked for reasons such as low severity of illness, suggesting that the Japanese healthcare system needs to provide additional support for these patients.

The Genetic Landscape of Mitochondrial Diseases in Spain: A Nationwide Call

“…The prevalence reported was 8 in 100,000 in the paediatric population and 5.7 in 100,000 in the general adult population in north-west Spain [9]. Recently, an interesting and extensive epidemiological study of MD patients in Japan was reported [13] in which the authors were able to recruit 3629 patients, estimating a prevalence of 2.9 per 100,000. However, only mtDNA-related diseases were considered, and this would explain the observation that the most susceptible age class was 40-49 years.…”

“…The description of new genes has also significantly increased [1][2][3]. There are some previous reports about MD prevalence in specific geographic areas of different countries [4][5][6][7][8][9][10][11][12][13]. Overall, a prevalence of 5-15 cases per 100,000 individuals was estimated [2].…”

Primary mitochondrial diseases: The intertwined pathophysiology of bioenergetic dysregulation, oxidative stress and neuroinflammation

“…Interestingly, based on several reports, it seems that the number of patients with mitochondrial diseases (caused by mutations in nuclear or mtDNA) in general population could be higher than it was originally estimated. For more details regarding the incidence of mitochondrial disorders, their geographic distribution and other information see Refs [7,[13][14][15][16][17]. More information regarding individual syndromes and deficiencies described above and many others as maternally inherited diabetes and deafness (MIDD), Alpers-Huttenlocher syndrome, Ataxia neuropathy spectrum, chronic progressive external ophthalmoplegia (CPEO), Pearson syndrome, mitochondrial neuro-gastro-intestinal encephalopathy (MNIGE), Sengers syndrome or MEGDEL syndrome can be found in the following reviews: Refs [2,[18][19][20][21].…”