The Korean undiagnosed diseases program: lessons from a one-year pilot project

Soo Yeon Kim†,
Byung Chan Lim†,
Jin Sook Lee†,
Woo Joong Kim,
Hyuna Kim,
Jung Min Ko,
Ki Joong Kim,
Sun Ah Choi,
Hunmin Kim,
Hee Hwang,
Ji Eun Choi,
Anna Cho,
Jangsup Moon,
Moon Woo Seong,
Sung Sup Park,
Yun Jeong Lee,
Young Ok Kim,
Jon Soo Kim,
Won Seop Kim,
Young Se Kwon,
June Dong Park,
Younjhin Ahn,
Joo-Yeon Hwang,
Hyun-Young Park,
Youngha Lee,
Murim Choi and
Jong-Hee ChaeEmail author

†Contributed equally

Orphanet Journal of Rare Diseases201914:68

https://doi.org/10.1186/s13023-019-1041-5

Received: 28 November 2018
Accepted: 28 February 2019
Published: 20 March 2019

Abstract

Background

The Korean Undiagnosed Diseases Program (KUDP) was launched in January 2017 as a one-year pilot project to address the increasing global interest in patients with undiagnosed rare diseases. The purpose of this paper is to summarize the project results and emphasize the unmet research needs among patients with undiagnosed rare diseases in Korea.

Results

Patient enrollment, assessment, and diagnostic processes were determined by the KUDP clinical expert consortium. Patients followed a diagnostic workflow after being categorized into one of four groups: I) insufficient clinical information or lack of standard diagnostic processes; II) undiagnosed due to low disease awareness; III) clinically diagnosed but unconfirmed genetically due to genetic heterogeneities; or IV) unknown disease due to complex, atypical clinical presentations. After excluding two patients from group I, 97 patients were enrolled, including 10 in group II, 67 in group III, and 20 in group IV. Most of them (92 of 97, 94.8%) were pediatric patients (< 18 years old) and 59 (60.8%) were male. The primary symptoms for 80 patients (82.5%) were neurologic. During the one-year pilot study, 72 patients completed a diagnostic assessment including clinical and molecular genetic analyses; some patients also underwent pathological or biochemical analysis. Twenty-eight of these patients (28/72, 38.9%) achieved molecular genetic diagnosis. Thirteen patients were diagnosed based on traditional tests, including biochemical assay, single or targeted genetic analysis, and chromosomal microarray. We performed whole exome sequencing on 52 patients, among whom 15 (28.8%, 15/52) reached a final diagnosis. One new disorder was identified via international collaboration.

Conclusions

Using an efficient clinical diagnostic workflow, this KUDP pilot study resulted in a fair diagnostic success rate, improving the potential for additional diagnoses and new scientific discovery of complex and rare diseases. KUDP also satisfied unmet needs for rare diseases with multisystem involvement, highlighting the value of emerging genomic technologies for further research into rare and still-undiagnosed conditions.