A bibliometric analysis of Kallmann syndrome: trends, hotspots, and future directions

Kallmann syndrome (KS) is a rare congenital disorder characterized by hypogonadotropic hypogonadism secondary to deficient gonadotropin-releasing hormone (GnRH) secretion, often accompanied by partial or complete anosmia. Deficient GnRH secretion results in decreased levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), causing impaired sexual development and absent secondary sexual characteristics. Against the backdrop of global expansion in rare disease research, KS has become a core research focus, and a comprehensive bibliometric analysis is required to chart the trajectory, trends, hotspots, and future paths in KS research over the last 15 years.

A systematic search of the Web of Science Core Collection (WOSCC) retrieved KS publications from January 1, 2009, to August 18, 2025, employing the search term "Kallmann syndrome" with the language restricted to English and no restrictions imposed on publication types. Data analyses were performed using VOSviewer for visualizing collaborative networks, CiteSpace for bursts and clusters, and R for statistics, to evaluate publication trends, countries, institutions, authors, journals, citations, and keywords.

KS publications exhibited steady double-digit annual growth, reaching 508 studies. The U.S. ranked first in publication volume, followed by Switzerland and France. Nelly Pitteloud (Switzerland) and Jacques Young (Paris Public Hospitals) were the most prolific and influential authors. The Journal of Clinical Endocrinology and Metabolism published the largest number of KS-related articles; Harvard University was the leading contributing institution. The most highly cited article, "Expert Consensus: European Consensus Statement on Congenital Hypogonadotropic Hypogonadism-Pathogenesis, Diagnosis and Treatment," was cited 575 times in total. Keywords identified hotspots like GnRH deficiency, hypogonadotropic hypogonadism, anosmia, and genetic mutations (> 30 genes), current research frontiers focusing on molecular pathogenesis and personalized therapies.

Our study provided a comprehensive overview of Kallmann syndrome research and showed the development status and scientific trend of Kallmann syndrome through bibliometric analysis from 2009 to 2025. The global volume of publications related to Kallmann syndrome has demonstrated a steady year-on-year increase. Research in this field is predominantly led by European and American countries, and cross-regional collaboration serves as a key driver for further advancement. In summary, these findings provide new perspectives for future relevant research and serve as a valuable reference to guide researchers in subsequent studies.