Pseudohypoparathyroidism (PHP) is extremely rare, and reported prevalence varies between countries. One large nationwide survey in Japan conducted in 2017 estimated the prevalence at 1.2 cases per 100,000 population. This represents an increase from an earlier estimate of 0.34 cases per 1,000,000 in 1997, and is likely due to improved recognition and diagnostic methods.[3]Takatani R, Kubota T, Minagawa M, et al. Prevalence of pseudohypoparathyroidism and nonsurgical hypoparathyroidism in Japan in 2017: a nationwide survey. J Epidemiol. 2023 Nov 5;33(11):569-73.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10518380
http://www.ncbi.nlm.nih.gov/pubmed/36123043?tool=bestpractice.com
One 2011 National Patient Registry review in Denmark identified 60 patients, a prevalence of 1.1 cases per 100,000 inhabitants.[4]Underbjerg L, Sikjaer T, Mosekilde L, et al. Pseudohypoparathyroidism - epidemiology, mortality and risk of complications. Clin Endocrinol (Oxf). 2016 Jun;84(6):904-11.
http://www.ncbi.nlm.nih.gov/pubmed/26387561?tool=bestpractice.com
In Poland, data from the National Health Fund spanning 2013-2023 suggests a lower prevalence of 0.62 to 0.64 per 100,000 person-years nationwide, though rates are higher in some subregions and time periods (up to 1.47).[5]Zygmunt A, Pacocha M, Domanska-Czajka A, et al. Analysis of the prevalence and incidence of pseudohypoparathyroidism in Poland based on National Health Fund data with clinical presentation of own cases. Front Endocrinol (Lausanne). 2025;16:1584154.
https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2025.1584154/full
http://www.ncbi.nlm.nih.gov/pubmed/40444234?tool=bestpractice.com
Based on expert opinion, type 1a is the most common form. Prevalence of PHP is higher in females.[3]Takatani R, Kubota T, Minagawa M, et al. Prevalence of pseudohypoparathyroidism and nonsurgical hypoparathyroidism in Japan in 2017: a nationwide survey. J Epidemiol. 2023 Nov 5;33(11):569-73.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10518380
http://www.ncbi.nlm.nih.gov/pubmed/36123043?tool=bestpractice.com
[4]Underbjerg L, Sikjaer T, Mosekilde L, et al. Pseudohypoparathyroidism - epidemiology, mortality and risk of complications. Clin Endocrinol (Oxf). 2016 Jun;84(6):904-11.
http://www.ncbi.nlm.nih.gov/pubmed/26387561?tool=bestpractice.com
[5]Zygmunt A, Pacocha M, Domanska-Czajka A, et al. Analysis of the prevalence and incidence of pseudohypoparathyroidism in Poland based on National Health Fund data with clinical presentation of own cases. Front Endocrinol (Lausanne). 2025;16:1584154.
https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2025.1584154/full
http://www.ncbi.nlm.nih.gov/pubmed/40444234?tool=bestpractice.com