A novel deep intronic variant strongly associates with Alkaptonuria.

Authors
Tsai, I-Jung 
Chiu, Pao-Chin 

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Abstract

Alkaptonuria is a rare autosomal recessive inherited disorder of tyrosine metabolism, which causes ochronosis, arthropathy, cardiac valvular calcification, and urolithiasis. The epidemiology of alkaptonuria in East Asia is not clear. In this study, patients diagnosed with alkaptonuria from January 2010 to June 2020 were reviewed. Their clinical and molecular features were further compared with those of patients from other countries. Three patients were found to have alkaptonuria. Mutation analyses of the homogentisate 1,2-dioxygenase gene (HGD) showed four novel variants c.16-2063 A > C, p.(Thr196Ile), p.(Gly344AspfsTer25), and p.(Gly362Arg) in six mutated alleles (83.3%). RNA sequencing revealed that c.16-2063 A > C activates a cryptic exon, causing protein truncation p.(Tyr5_Ile6insValTer17). A literature search identified another 6 patients with alkaptonuria in East Asia; including our cases, 13 of the 18 mutated alleles have not been reported elsewhere in the world. Alkaptonuria is rare in Taiwan and East Asia, with HGD variants being mostly novel and private.

Publication Date
2021-10-22
Online Publication Date
2021-10-22
Acceptance Date
2021-10-04
Keywords
Article, /692/4017, /692/699/317, article
Journal Title
NPJ Genom Med
Journal ISSN
2056-7944
2056-7944
Volume Title
6
Publisher
Springer Science and Business Media LLC
Sponsorship
Ministry of Science and Technology, Taiwan (Ministry of Science and Technology of Taiwan) (107-2314-B-002 -164 -MY3)
National Taiwan University Hospital (NTUH) (NTUH 105-002959, NTUH 105-002959)