Table 1. Hematological data, ALAS2 exon... | American Society of Hematology

Table 1.

Hematological data, ALAS2 exon 9 sequence (from 1230 to 1240 nucleotide), and results of X-chromosome inactivation studies using HUMARA assay in the family members

Subject	Age, y	Hb, g/L	MCV, fL	RDW, %	Serum ferritin, μg/L	ALAS2 paternal allele	ALAS2 paternal allele	HUMARA cleavage ratio^* between alleles
Proband
Before manifestations	36	136	ND	ND	ND
At clinical onset	64	52	64	ND	ND
Under transfusion	71	70	81	22.5	3954
Under pyridoxine	74	123	85	18.9	2430	TTGGCTATGTG	TTGGCTGTGTG^†	Not informative
Daughter II-2	52	137	88	17.7	110	TTGGCTATGTG	TTGGCTGTGTG^†	3.2
Daughter II-3	50	132	92	17.1	126	TTGGCTATGTG	TTGGCTGTGTG^†	4.0
Grandson III-1
At diagnosis	14	79	63	ND	384
Under pyridoxine	29	145	72	18.9	810	—	TTGGCTGTGTG
During phlebotomy	30	138	78	16.1	122
After phlebotomy	31	146	73	19.3	89
Granddaughter III-2	32	130	85	16.6	82	TTGGCTATGTG	TTGGCTGTGTG	4.0
Normal range		F 12.0 -16.0	83-97	11-14	F 12 -200
		M 13.5-17.5			M 20-250

Subject	Age, y	Hb, g/L	MCV, fL	RDW, %	Serum ferritin, μg/L	ALAS2 paternal allele	ALAS2 paternal allele	HUMARA cleavage ratio^* between alleles
Proband
Before manifestations	36	136	ND	ND	ND
At clinical onset	64	52	64	ND	ND
Under transfusion	71	70	81	22.5	3954
Under pyridoxine	74	123	85	18.9	2430	TTGGCTATGTG	TTGGCTGTGTG^†	Not informative
Daughter II-2	52	137	88	17.7	110	TTGGCTATGTG	TTGGCTGTGTG^†	3.2
Daughter II-3	50	132	92	17.1	126	TTGGCTATGTG	TTGGCTGTGTG^†	4.0
Grandson III-1
At diagnosis	14	79	63	ND	384
Under pyridoxine	29	145	72	18.9	810	—	TTGGCTGTGTG
During phlebotomy	30	138	78	16.1	122
After phlebotomy	31	146	73	19.3	89
Granddaughter III-2	32	130	85	16.6	82	TTGGCTATGTG	TTGGCTGTGTG	4.0
Normal range		F 12.0 -16.0	83-97	11-14	F 12 -200
		M 13.5-17.5			M 20-250

RDW indicates RBC distribution width, ie, the mean SD of RBC volume expressed as a percentage of the mean RBC volume. The ALAS2 paternal allele is a wild-type sequence: TTGGCTATGTG. Mutations are shown as bold fonts. ND indicates not done; F, female; M, male.

If a woman is a perfect mosaic (50% of cells expressing the paternally derived X chromosome and 50% expressing the maternally derived one), the cleavage ratio is 1. A cleavage ratio of greater than 3 was previously established as the cut-off between cases with balanced X-chromosome inactivation (ratio, < 3) and cases with excessive skewing (ratio ≥ 3).7

†

The mutated allele is supposed to be of maternal origin because the father did not have any manifestation of congenital anemia and therefore could not be a hemizygote.

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