Correction to: Rapid and reliable detection of α-globin copy number variations by quantitative real-time PCR

Correction to: BMC Hematol (2014) 14:4

https://doi.org/10.1186/2052-1839-14-4

The copy number of the HBA1 assay for the -(α)^20.5 deletion in the HBA-CNV method described in the original article [1] was incorrectly reported. The authors wish to note that the HBA1 assay will not be affected by the –(α)^20.5 deletion and will show two copies (Table 1 - corrected). The 3′ breakpoint of the –(α)^20.5 deletion is located within exon 2 of the HBA1 gene [2], leaving intact the area where the HBA1 assay is amplifying. The partial deletion of HBA1 causes a complete abolition of the gene expression, hence –(α)^20.5 is considered as a double gene deletion. This shows that even though the HBA1 assay may show two copies, a deletion affecting both alpha-globin genes can not be excluded. Similarly, the Hb Var database contains examples of deletions that will not influence HBA2 assay copy number despite affecting both alpha-globin genes. Hence, molecular data should always be evaluated together with hematological data.

Table 1.

Predicted copy number in 108 patient samples

Genotype	Samples (n)	Copy Number Predicted
		HBA1	HBA3.7	HBA2	HS-40
αα/αα	63	2	2	2	2
-α3.7/αα	22	2	1	2	2
-α4.2/αα	2	2	2	1	2
-α3.7/-α3.7	8	2	0	2	2
--SEA/αα	7	1	1	1	2
--FIL/αα	1	1	1	1	2
-(α)20.5/αα	1	2	1	1	2
--MED/αα	1	1	1	1	2
-α3.7/--SEA	1	1	0	1	2
αα/αααanti3.7	2	2	3	2	2
Total	108