Analysis of clinical characteristics and treatment efficacy in two pediatric cases of ANKRD26-related thrombocytopenia

Figures & data

Table I. Patients’ clinical characteristics.

Patient ID	Sex	Age (years)	Symptoms	WHO scale	malignancy	Family members with thrombocytopenia
1	Male	1	Easy bruising	1	None	Father (PLT76–91.5 × 10^9/L)
2	Female	1	Recurrent haemorrhagic spots	1	None	Father (PLT34–82 × 10^9/L)

PLT: Platelet.

Table II. Patients’ laboratory characteristics.

Patient ID	PLT (×10^9/L)	WBC (×10^9/L)	HB (g/L)	MPV (fl)	PLT morphology	Bone marrow aspiration	Megakaryocyte lineage of bone marrow	ANKRD26 mutation	Family ANKRD26 mutation
1	2	14.80	110	10.03	Normal	Megakaryocyte maturation impairment not obvious	Classified as 50, including 2 promegakaryocytes(4%), 36 granular megakaryocytes(72%), 8 thrombocytogenic megakaryocytes(16%), 4 naked megakaryocytes(8%), few platelets	c.-140C>G in 5’UTR	Father(c.-140C>G in 5’UTR)
2	40	4.46	131	9.60	Normal	Megakaryocyte maturation impairment not obvious	Classified as 50, including 8 promegakaryocytes(16%), 40 granular megakaryocytes(80%), 2 thrombocytogenic megakaryocytes(4%), few platelets	c.-127A>T in 5’UTR,	Father(c.-127A>T in 5’UTR),

HB: Hemoglobin; MPV: Mean platelet volume; PLT: Platelet; WBC: White blood cell; Normal megakaryocyte lineage reference values: megakaryobiast 0%-5%, promegakaryocytes 5%-10%, granular megakaryocytes 55%-75%, thrombocytogenic megakaryocytes 10%-30%, naked megakaryocytes 0%-20%.

Figure 1. Representative chromatograms from direct sequencing of the ANKRD26 gene. The red arrow indicates the mutation position. (a) represents the mutation c.-140C>G of ANKRD26 in 5’UTR in patient 1. (b) represents the mutation c.-127A>T of ANKRD26 in 5’UTR in patients 2.

Figure 2. (a) Therapeutic effect of immunosuppressor in patient 1. (b) Therapeutic effect of immunosuppressor in patient 2.

Table III. Therapeutic effect of immunosuppressor.

	Patient 1	Patient 2
PLT before treatment (×10^9/L)	2	40
Immunosuppressant	IVIG, Prednisone, Dexamethasone, Rituximab	Prednisone
Total course of treatment	3 months	15 months discontinuously
PLT at 4 weeks of treatment (×10^9/L)	22.4	60
Platelet count at the end of treatment (×10^9/L)	20	40
PLT of the total course (×10^9/L)	4–51	34–72
Response of the total course	Temporary response, but not sustained	No response

PLT: Platelet, IVIG: Intravenous immunoglobulin.

Table IV. Therapeutic effect of eltrombopag.

	Patient 1	Patient 2
PLT before treatment(×10^9/L)	29.8	40
Total course of treatment	2 months	1 months
Dose	25 mg/d	25 mg/d
PLT at 4 weeks of treatment(×10^9/L)	18	55
PLT at 8 weeks of treatment(×10^9/L)	11.3	None
Response of the total course	No responsive	No responsive
Adverse events	None	Little rash

PLT: Platelet.

Figure 3. Representative mutations in 5’UTR of the ANKRD26 gene associated with ANKRD26-RT. Position c-172 indicates the transcription start site (TSS). Green and blue areas represent RUNX1 and FLI1 binding sites. The red position represents the location of the mutation in our patient.