PMC4672090_01
Morphology of the bone marrow biopsy before treatment. (A) May-Giemsa Grunwald (MGG), x10: cellularity around 40%, considered to be normal for the patients age of 37, with normally distributed megakaryocytes. (B) MGG, x40: some dysplastic megakaryocytes (arrow) with hypolobulated nuclei. (C) Gomori silver stain: normal content of reticulin fibers.
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No fibrosis was found (Fig. 1).
Molecular diagnostic and genetic workup. (A) Pedigree of the affected family. Arrow indicates the index patient. (B) Germline mutation Gly136Argfs*49 mapped to the GATA2 protein structure using the software DOG1.0. (C) Genetic testing of the affected family by Sanger sequencing. Chromatograms of the index patient and her parents show a partial sequence of GATA2 exon 3 surrounding the cDNA position 404. (D) Exome sequence data from the index patient supporting the GATA2 germline mutation and the somatic ASXL1 mutation. Alignments of matched tumor (bone marrow) and normal (skin biopsy) samples from the index patient are shown using the Integrative Genomics Viewer (IGV). Read counts of reference and variant alleles at the altered positions are indicated for each sample.
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In particular, no other family members are known to be affected by any type of hematological malignancy or immunodeficiency (Fig. 2 A). Sequencing of material from both bone marrow and skin biopsy showed a heterozygous frameshift mutation in GATA2 (NM_001145661.1:c.404dup;Gly136Argfs*49) (Fig. 2, B-D). The patient's parents were tested but no GATA2 mutation could be detected (Fig. 2 C), suggesting that the patients disorder was caused by a de-novo mutation. Thereby, we detected a somatic ASXL1 mutation (NM_015338.4:c.2077 C>T; Arg693*) (Fig. 2 D).