Monosomy 7 (MDS/AML)
45,XX,-7
Also known as: -7, monosomy 7
45,XX,-7 is an acquired monosomy: one whole copy of chromosome 7 is lost in the malignant cells. Monosomy 7 is among the most common cytogenetic abnormalities in myelodysplastic syndrome and acute myeloid leukemia and carries an unfavorable prognosis.
Open in the interactive visualizer →
What the notation means
The shape of this abnormality
- count
- total chromosome count (normal = 46)
- sex chromosomes
- sex chromosomes: two X (usual female karyotype)
- abnormality
- LOSS of one chromosome 7 (one copy = monosomy 7)
Clinical notes
monosomy 7 / del(7q), MDS and AML
This is the most common adverse numeric lesion of myeloid disease, whether the whole chromosome goes or only 7q. It is classic after alkylating chemotherapy or radiation, five to seven years out, often beside del(5q) and TP53 loss. In a child or young adult it prompts a thought about germline predisposition, GATA2 deficiency and SAMD9/SAMD9L, in which a marrow can even lose the mutant-bearing chromosome 7 as an adaptation. The unbalanced der(1;7)(q10;p10), which also costs 7q, has its own entry.