1. Long-read Amplicon Sequencing of the CYP21A2 in 48 Thai Patients With Steroid 21-Hydroxylase Deficiency.
- Author
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Tantirukdham, Nithiphut, Sahakitrungruang, Taninee, Chaisiwamongkol, Ratikorn, Pongpanich, Monnat, Srichomthong, Chalurmpon, Assawapitaksakul, Adjima, Buasong, Aayalida, Tongkobpetch, Siraprapa, Yeetong, Patra, and Shotelersuk, Vorasuk
- Subjects
ADRENOGENITAL syndrome ,HYDROXYLASES - Abstract
Context: Congenital adrenal hyperplasia is most commonly caused by 21-hydroxylase deficiency (21-OHD), an autosomal recessive disorder resulting from biallelic pathogenic variants (PVs) in CYP21A2. With a highly homologous pseudogene and various types of single nucleotide and complex structural variants, identification of PVs in CYP21A2 has been challenging. Objective: To leverage long-read next-generation sequencing combined with locus-specific polymerase chain reaction (PCR) to detect PVs in CYP21A2 and to determine its diagnostic yield in patients with 21-OHD. Methods: Forty-eight Thai patients with 21-OHD comprising 38 sporadic cases and 5 pairs of siblings were enrolled. Two previously described locus-specific PCR methods were performed. Amplicons were subject to long-read sequencing. Results: Ninety-six PVs in CYP21A2 in the 48 patients were successfully identified. The combined techniques were able to detect 26 structural chimeric variants (27%; 26/96) in 22 patients with 18 having monoallelic and 4 having biallelic chimeras. The remaining PVs were pseudogene-derived mutations (63%; 60/96), entire gene deletions (2%; 2/96), missense variants (3%; 3/96), a splice-site variant (2%; 2/96), frameshift variants (2%; 2/96), and a nonsense variant (1%; 1/96). Notably, a splice-site variant, IVS7 + 1G > T, which was identified in a pair of siblings, has not previously been reported. Conclusions: Our approach exploiting locus-specific PCR and long-read DNA sequencing has a 100% diagnostic yield for our cohort of 48 patients with 21-OHD. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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