Novel frameshift mutation causes early termination of the thyroxine-binding globulin protein and complete thyroxine-binding globulin deficiency in a Chinese family: A case report

Table 1 Primers used in PCR amplification and sequencing

Primer ID	Primer sequence
Sequencing
Exon 1
SERPINA7-F	AGAGAAACCCCTGCTCAG
SERPINA7-R	TTTCCTGGACTCATTCACAG
Exon 2
SERPINA7-F	GGTACCTAACTCTGTGGTGA
SERPINA7-R	CATAGCTGTTGGGTAGTTCA
Exon 3
SERPINA7-F	TGGTTATCAATACTCAGGGAAG
SERPINA7-R	TCTAGCTTAGGAGGAGTCAC
Exon 4
SERPINA7-F	ACTACATTTAGCAGAGGAAAC
SERPINA7-R	CAAAGTTCAGCCAGGGTT
qPCR-HRM
TBG-Poly of exon 3
Forward primer	AAAGTGTGGCTCCAAGGTCA
Reverse primer	GGTGATTGCCATGTGTTCCC
Sanger sequencing
TBG-Poly of exon 3
Forward primer	AGAGAGAAGGAGAGAATCATAAGC
Reverse primer	TGGAAAGTTTCAGACCATTGTC
TBG-Xq22G>A
Forward primer	GTTGGGAAACTGGAAGGAGA
Reverse primer	AGAGGTGGAAAGGGGAAGAG

Gene regions including exons 1-4 of the TBG gene and intron-exon boundaries were sequenced. Quantitative PCR high-resolution melting (HRM) curve analysis was adopted to detect the TBG-Poly (L283F) variant. Sanger sequencing was used to confirm the mutation identified by HRM and to detect the TBG-Xq22G>A mutation. qPCR-HRM: Quantitative PCR high-resolution melting; TBG-Poly: TBG polymorphism (L283F).