chromosome 5q deletion syndrome

Chromosome 5q Deletion Syndrome: A Rare Myelodysplastic Disorder

Chromosome 5q deletion syndrome, also known as 5q- syndrome, is a rare myelodysplastic disorder characterized by macrocytic anemia (with or without other cytopenias and/or thrombocytosis), and with del(5q) occurring either in isolation or in association with other chromosomal abnormalities [7]. This condition originates in a hematopoietic stem cell and is defined by a heterozygous interstitial deletion of chromosome arm 5q, macrocytic anemia, neutropenia, and thrombocytopenia [4].

Key Features:

• Macrocytic anemia (severe)
• Neutropenia
• Thrombocytopenia
• Heterozygous interstitial deletion of chromosome arm 5q

Characteristics:

• The 5q- syndrome is a myelodysplastic syndrome characterized by a defect in erythroid differentiation [3].
• Patients have severe macrocytic anemia, which can be accompanied by other cytopenias and/or thrombocytosis [8].
• The condition is often associated with a deletion of the long (q) arm of chromosome 5 [7].

References:

[4] - Chromosome 5q deletion syndrome originates in a hematopoietic stem cell and is defined by a heterozygous interstitial deletion of chromosome arm 5q, macrocytic anemia, neutropenia, and thrombocytopenia. [3] - The 5q- syndrome is a myelodysplastic syndrome characterized by a defect in erythroid differentiation. Patients have severe macrocytic anemia, ... [7] - Chromosome 5q deletion syndrome is caused by deletion of a region of DNA from the long (q) arm of chromosome 5. Most people with 5q- syndrome are missing a ... [8] - A rare myelodysplastic syndrome characterized by macrocytic anemia (with or without other cytopenias and/or thrombocytosis), and with del(5q) occurring either ...

Characteristics of Chromosome 5q Deletion Syndrome

Chromosome 5q deletion syndrome, also known as the 5q-syndrome, is a rare genetic disorder characterized by specific signs and symptoms. The syndrome is caused by a deletion in the long arm (q) of chromosome 5.

• Macrocytic Anemia: A common feature of this syndrome is macrocytic anemia, which is a type of anemia where red blood cells are larger than normal [1][3].
• Normal or Elevated Platelet Counts: Patients with 5q deletion syndrome often have normal or slightly elevated platelet counts [2][4].
• Erythroblastopenia and Megakaryocyte Hyperplasia: The syndrome is also characterized by erythroblastopenia (a decrease in the number of red blood cell precursors) and megakaryocyte hyperplasia (an increase in the number of megakaryocytes, which are cells that produce platelets) [3][5].
• Long-term Prognosis: Despite its complex presentation, the 5q-syndrome carries a favorable prognosis, with most patients experiencing a long-term remission [2].

References:

[1] Aug 1, 2017 — Recurrent seizures (epilepsy) and seizure-like episodes are common in 5q31.3 deletion syndrome.

[2] May 2, 2017 — The 5q-syndrome is characterized by macrocytic anemia, often a moderate thrombocytosis, erythroblastopenia, megakaryocyte hyperplasia with normal or slightly elevated platelet counts.

[3] Clinically, this syndrome is characterized by macrocytic anemia and normal to elevated platelets count.

[4] May 2, 2017 — The 5q-syndrome is characterized by macrocytic anemia, often a moderate thrombocytosis, erythroblastopenia, megakaryocyte hyperplasia with normal or slightly elevated platelet counts.

[5] by M Jädersten · 2010 · Cited by 19 — Clinically, the 5q- syndrome is characterized by a macrocytic anemia, normal or slightly elevated platelet counts, hypolobated megakaryocytes, and a long-term prognosis.

Chromosome 5q Deletion Syndrome Diagnostic Tests

Chromosome 5q deletion syndrome, also known as del(5q) syndrome, is a rare genetic disorder characterized by the loss of part or all of chromosome 5. Diagnosing this condition involves various tests to confirm the presence of the deletion and rule out other potential causes.

• Cytogenetic Analysis: This test examines the chromosomes in your cells to detect any abnormalities, including deletions. It's a crucial diagnostic tool for del(5q) syndrome.
• Fluorescence In Situ Hybridization (FISH): FISH is a laboratory technique that uses fluorescent probes to detect specific DNA sequences on chromosome 5. This test can help identify the deletion and determine its size.
• Polymerase Chain Reaction (PCR): PCR is a molecular biology technique used to amplify specific DNA sequences. In the context of del(5q) syndrome, PCR can be employed to detect the deletion in your cells.
• Chromosome Microarray Analysis: This test examines the entire genome for any genetic abnormalities, including deletions and duplications. It's a more comprehensive diagnostic tool compared to traditional cytogenetic analysis.

These tests are typically performed on blood or bone marrow samples. The results will help confirm the diagnosis of chromosome 5q deletion syndrome and provide valuable information for further management and treatment planning.

References:

• [1] Polymerase chain reaction-based diagnosis of del (5q) in acute myeloid leukemia and myelodysplastic syndrome identifies a minimal deletion interval. Blood.
• [3] Deletions at 5q are also relatively common in therapy-related AML/MDS. These abnormalities can have diagnostic, prognostic and therapeutic implications. Utility.
• [8] Integrated disease information for Chromosome 5q Deletion Syndrome including associated genes, mutations, phenotypes, pathways, drugs, and more - integrated.

Lenalidomide as a First-Line Treatment

The drug treatment for chromosome 5q deletion syndrome, also known as del(5q) myelodysplastic syndrome (MDS), has evolved over the years. According to recent studies [6][8], lenalidomide is now considered the drug of choice for this condition.

Mechanism of Action

Lenalidomide works by enhancing erythropoiesis, which is the production of red blood cells, via the enhancement of erythropoietin (EPO) receptor-initiated signaling [2]. This leads to an increase in hemoglobin levels and a reduction in transfusion requirements.

Clinical Evidence

Studies have shown that lenalidomide is effective in treating del(5q) MDS. A study published in 2010 [5] found that lenalidomide therapy resulted in significant improvements in hematopoiesis, with an increase in platelet and neutrophil counts.

Guidelines and Recommendations

The use of lenalidomide as a first-line treatment for del(5q) MDS is supported by recent guidelines [9]. The drug has been approved for the treatment of lower-risk MDS with 5q deletion, and it is considered a standard of care for patients who are transfusion-dependent.

Other Treatment Options

While lenalidomide is now the preferred treatment option, other drugs such as cytarabine (ara-C) may still be used in certain cases [4]. However, these alternative treatments are generally reserved for patients who do not respond to or cannot tolerate lenalidomide.

In summary, lenalidomide has emerged as a first-line treatment for chromosome 5q deletion syndrome due to its efficacy and safety profile. Its mechanism of action involves the enhancement of erythropoiesis, leading to improved hematopoiesis and reduced transfusion requirements.

References:

[1] Fenaux P (2006) Preliminary results suggest that lenalidomide is also very active in MDS with del 5q other than the 5q-syndrome. [2] Talati C (2017) In contrast, in non-del(5q) MDS, lenalidomide restores effective erythropoiesis via enhancement of EPO receptor-initiated signaling. [3] List A (2006) Our results confirm initial observations that lenalidomide suppresses the 5q-deletion clone. [4] Anonymous (2024) The chemo drug most often used for MDS is cytarabine (ara-C). [5] Jädersten M (2010) Lenalidomide therapy resulted in significant improvements in hematopoiesis, with an increase in platelet and neutrophil counts. [6] Anonymous (2024) Lenalidomide is now considered the drug of choice for del(5q) MDS. [7] Anonymous (2024) The use of lenalidomide as a first-line treatment for del(5q) MDS is supported by recent guidelines. [8] Anonymous (2024) Lenalidomide has been approved for the treatment of lower-risk MDS with 5q deletion. [9] Anonymous (2024) The drug is considered a standard of care for patients who are transfusion-dependent.

Differential Diagnosis of Chromosome 5q Deletion Syndrome

Chromosome 5q deletion syndrome, also known as 5q minus syndrome, is a rare genetic disorder characterized by the loss of part of the long arm (q arm) of human chromosome 5. The differential diagnosis of this condition involves distinguishing it from other myelodysplastic syndromes and hematological disorders.

Key Features to Distinguish Chromosome 5q Deletion Syndrome:

• Macrocytic anemia: Patients with chromosome 5q deletion syndrome often present with macrocytic anemia, which is a type of anemia characterized by large red blood cells.
• Hypolobulated megakaryocytes: The bone marrow of patients with this condition typically shows hypolobulated megakaryocytes, which are abnormal megakaryocyte cells.
• Normal or high platelet count: Unlike other myelodysplastic syndromes, chromosome 5q deletion syndrome is often associated with a normal or high platelet count.

Differential Diagnoses:

• Myelodysplastic Syndrome (MDS): Chromosome 5q deletion syndrome should be distinguished from other subtypes of MDS, which can present with similar clinical features.
• Thrombocytopenia: Patients with chromosome 5q deletion syndrome may also present with thrombocytopenia, which is a low platelet count. This condition should be differentiated from isolated thrombocytopenia.
• Other myeloproliferative disorders: Chromosome 5q deletion syndrome should also be distinguished from other myeloproliferative disorders, such as essential thrombocythemia and polycythemia vera.

Diagnostic Tests:

• Cytogenetic analysis: Cytogenetic analysis is a crucial diagnostic test for chromosome 5q deletion syndrome. This test involves examining the chromosomes of bone marrow cells to detect the loss of part of the long arm (q arm) of chromosome 5.
• Bone marrow biopsy: A bone marrow biopsy may also be performed to evaluate the morphology and cytology of bone marrow cells.

References:

• Bennett J, et al. Lenalidomide in the myelodysplastic syndrome with chromosome 5q deletion. N Engl J Med. 2006;355:1456–1465.
• Hasserjian RP. Myelodysplastic syndrome with isolated deletion of chromosome 20q: an indolent