Monosomy 7: Symptoms, Leukemia, MDS/AML, Life Expectancy, ICD-10 & Genetics

Content:

• What is Monosomy 7?
• Symptoms
• Leukemia
• MDS/AML
• Life Expectancy
• ICD-10
• Genetics

What is Monosomy 7?

Monosomy 7 is a rare chromosomal abnormality in which one copy of chromosome 7 is missing from the cells. Instead of the normal two copies of chromosome 7, affected cells contain only one. This cytogenetic abnormality is strongly associated with blood disorders, particularly myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). It may be found in both children and adults, although pediatric cases are often linked to inherited predisposition syndromes or bone marrow failure disorders.

This chromosomal deletion is clinically important because it usually indicates a poor prognosis, resistance to standard therapies, and higher risk of progression to aggressive leukemia. Monosomy 7 can appear as a primary abnormality or as part of a complex karyotype. In many cases, hematologists use its detection as a factor in deciding whether early stem cell transplantation may be necessary.

Symptoms

Monosomy 7 itself does not directly cause visible symptoms, but the blood disorders associated with it lead to significant clinical features. Common symptoms include:

• Persistent fatigue and weakness due to anemia
• Frequent infections caused by low white blood cell counts
• Easy bruising or bleeding from reduced platelets
• Pallor and shortness of breath on exertion
• Bone marrow failure signs such as pancytopenia

Children with inherited forms of monosomy 7 may present with early bone marrow dysfunction, growth abnormalities, or be diagnosed during evaluation of recurrent fevers and infections. The presence of symptoms usually depends on the severity of the underlying disorder (MDS or AML) rather than the chromosomal abnormality alone.

Leukemia

Monosomy 7 is closely associated with acute myeloid leukemia (AML), particularly in cases arising from prior myelodysplastic syndromes. In pediatric cases, monosomy 7 often indicates aggressive leukemia and can be linked with genetic predisposition syndromes such as Shwachman-Diamond syndrome or GATA2 deficiency.

Patients with AML and monosomy 7 generally respond poorly to conventional chemotherapy, which makes early identification critical. Hematopoietic stem cell transplantation (HSCT) is often considered the most effective treatment strategy in eligible patients, offering the best chance of long-term remission. Prognosis varies depending on patient age, comorbidities, and coexisting mutations.

MDS/AML

Myelodysplastic syndromes (MDS) with monosomy 7 are among the most aggressive subtypes. This cytogenetic abnormality is considered a high-risk factor in IPSS-R scoring (Revised International Prognostic Scoring System). Patients with monosomy 7-positive MDS have a high likelihood of transforming to AML within months to a few years.

Monosomy 7 is also seen in therapy-related MDS/AML, which occurs after prior exposure to chemotherapy or radiation. In both adults and children, this abnormality signals poor prognosis and need for timely transplant evaluation. Supportive care such as transfusions, growth factors, and antibiotics are often needed while planning definitive treatment.

Life Expectancy

Life expectancy in patients with monosomy 7 varies significantly based on age, overall health, and treatment access. Without treatment, survival is generally poor, ranging from a few months to 2 years in cases of AML or high-risk MDS. In children with inherited predisposition, progression may be slower, but the long-term risk of leukemia is high.

Stem cell transplantation remains the most effective intervention, improving survival rates for both children and adults. Studies suggest that patients undergoing successful HSCT may achieve long-term survival, though relapse remains a risk. Early diagnosis, genetic counseling, and careful monitoring are crucial for improving life expectancy in affected patients.

ICD-10

There is no single ICD-10 code specifically for "monosomy 7" alone. Instead, coding is based on the associated hematological disorder. Commonly used ICD-10 codes include:

• C92.0 – Acute myeloid leukemia not having achieved remission
• C92.9 – Acute myeloid leukemia, unspecified
• D46.Z – Other myelodysplastic syndromes
• Q99.9 – Chromosomal abnormality, unspecified (if needed for general documentation)

Clinicians usually link monosomy 7 to AML or MDS coding rather than listing it separately.

Genetics

Monosomy 7 results from the loss of one copy of chromosome 7. This chromosome carries many genes crucial for normal bone marrow and blood cell development. The deletion can occur spontaneously (acquired) or may be inherited as part of syndromic conditions. Genes on chromosome 7 that are often implicated include SAMD9, SAMD9L, CUX1, and others related to hematopoiesis.

Inherited predisposition syndromes such as GATA2 deficiency, SAMD9/SAMD9L mutations, Shwachman-Diamond syndrome, and Fanconi anemia may increase the risk of developing monosomy 7. In these families, genetic counseling and early bone marrow monitoring are recommended. The genetic landscape of monosomy 7 continues to be studied to better understand its mechanisms and develop targeted therapies.