5q minus syndrome

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

5q minus (5q-) syndrome is a type of bone marrow disorder called myelodysplastic syndrome (MDS). MDS comprises a group of conditions in which immature blood cells fail to develop normally, resulting in too many immature cells and too few normal mature blood cells. In 5q- syndrome, development of red blood cells is particularly affected, leading to a shortage of these cells (anemia). In addition, the red blood cells that are present are unusually large (macrocytic). Although many people with 5q- syndrome have no symptoms related to anemia, especially in the early stages of the condition, some affected individuals develop extreme tiredness (fatigue), weakness, and an abnormally pale appearance (pallor) as the condition worsens. Individuals with 5q- syndrome also have abnormal development of bone marrow cells called megakaryocytes, which produce platelets, the cells involved in blood clotting. A common finding in people with 5q- syndrome is abnormal cells described as hypolobated megakaryocytes. In addition, some individuals with 5q- syndrome have an excess of platelets, while others have normal numbers of platelets.

MDS is considered a slow-growing (chronic) blood cancer. It can progress to a fast-growing blood cancer called acute myeloid leukemia (AML). Progression to AML occurs less commonly in people with 5q- syndrome than in those with other forms of MDS.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

5q- 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 sequence of about 1.5 million DNA building blocks (base pairs), also written as 1.5 megabases (Mb). However, the size of the deleted region varies. This deletion occurs in immature blood cells during a person's lifetime and affects one of the two copies of chromosome 5 in each cell.

The commonly deleted region of DNA contains 40 genes, many of which play a critical role in normal blood cell development. Research suggests that loss of multiple genes in this region contributes to the features of 5q- syndrome. Loss of the RPS14 gene leads to the problems with red blood cell development characteristic of 5q- syndrome, and loss of MIR145 or MIR146A contributes to the megakaryocyte and platelet abnormalities and may promote the overgrowth of immature cells. Scientists are still determining how the loss of other genes in the deleted region might be involved in the features of 5q- syndrome.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is generally not inherited but arises from a mutation in the body's cells that occurs after conception. This alteration is called a somatic mutation. Affected people typically have no history of the disorder in their family.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

MDS affects nearly 1 in 20,000 people in the United States. It is thought that 5q- syndrome accounts for 15 percent of MDS cases. Unlike other forms of MDS, which occur more frequently in men than women, 5q- syndrome is more than twice as common in women.

Understanding terms used in the source

These definitions explain medical words used above. A definition is not evidence that another condition is present, and it does not predict how a symptom will develop. Ask the clinician which terms apply to the actual examination or test result.

Acute myeloid leukemia

A form of leukemia characterized by overproduction of an early myeloid cell.

Myeloid leukemia

A leukemia that originates from a myeloid cell, that is the blood forming cells of the bone marrow.

Overgrowth

Excessive postnatal growth which may comprise increased weight, increased length, and/or increased head circumference.

Affected

This term applies to a family member who is diagnosed with the same condition as the individual who is the primary focus of investigation (the proband).

Leukemia

A cancer of the blood and bone marrow characterized by an abnormal proliferation of leukocytes.

Which doctor should you see?

The suggested department for discussing 5q minus syndrome is Clinical Genetics, with a clinical geneticist as the relevant type of clinician. Paediatrician (children) or physician (adults), with clinical geneticist referral.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Does the exact genetic or chromosome finding explain the observed features?
• Would a genetic counsellor help the family understand the result?
• Which organ-specific assessments are appropriate for this particular diagnosis?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for 5q minus syndrome. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.