A new recurrent 9q34 duplication in pediatric T-cell acute lymphoblastic leukemia (2023)

FAQs

What chromosome is 9q34 on? ›

A 9q34 duplication is a very rare genetic condition in which there is a small extra piece of one of the 46 chromosomes – chromosome 9.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive form of blood cancer. It falls into a broader category of leukemia called acute lymphoblastic leukemia (ALL). ALL is the most common form of cancer in children. It's most often diagnosed between ages 2 and 10.

Relapsed T-ALL occurs in up to 25% of children and is associated with a much poorer prognosis (30-50% survival).

With current treatments, the overall survival rate at 5 years in children with lymphoblastic lymphoma is 80-90%, and the overall survival rate in adults is 45-55%.

Individuals with dup 9q34 have slight psychomotor retardation, understand simple directions, and acquire a limited vocabulary. In childhood, many are hyperactive. Clinical features include low birth weight, normal birth length, and initial poor feeding and thriving.

Features that often occur in people with Chromosome 9p duplication include developmental delay, intellectual disability, behavioral problems and distinctive facial features. Chromosome testing of both parents can provide more information on whether or not the duplication was inherited.

T-cell markers are CD1a, CD2, CD3 (membrane and cytoplasm), CD4, CD5, CD7 and CD8. CD2, CD5 and CD7 antigens are markers of the most immature T-cell cells, but none of them is absolutely lineage-specific, so that the unequivocal diagnosis of T-ALL rests on the demonstration of surface/cytoplasmic CD3.

Virtually all patients with T-ALL will start treatment immediately. The main exception would be if a patient is very ill with other medical problems and is not fit enough to receive treatment. Acute leukaemia is often curable with standard treatments, in younger and/or fitter patients.

It is one of two forms of acute lymphoblastic leukemia (ALL), the most common childhood cancer. Doctors diagnose around 6,600 individuals with ALL annually. T-ALL accounts for approximately 12–15% of child cases and up to 25% of adult cases of ALL.

T cell acute lymphoblastic leukaemia (T-cell ALL)

It might also be called pre (precursor) T cell ALL. This is more likely to affect young adults and is more common in men. Around 25 out of every 100 people with ALL (around 25%) are this type.

What is the survival rate of a child with T cell lymphoma? ›

The 5-year relative survival rate for children ages 0 to 14 with NHL is 91%. The 5-year relative survival rate for teens ages 15 to 19 is 89%. The survival rates for childhood NHL vary based on several factors.

T-cell childhood acute lymphoblastic leukemia

Children with T-ALL are given more anticancer drugs and higher doses of anticancer drugs than children in the newly diagnosed standard-risk group. Intrathecal and systemic chemotherapy are given to prevent or treat the spread of leukemia cells to the brain and spinal cord.

Adult T-cell leukemia/lymphoma (ATLL) is a rare and often aggressive (fast-growing) T-cell lymphoma that can be found in the blood (leukemia), lymph nodes (lymphoma), skin, or multiple areas of the body.

Survival with treatment is measured in months to a year. Four-year survival is approximately 5 to 10 percent and median survival is 8 to 10 months when treated with regimens devised for advanced, aggressive non-Hodgkin lymphoma.

What is the survival rate for T-cell leukemia? Due to the rarity of T-cell leukemia, specific survival rates are not available. It is estimated that 4,490 deaths (2,830 males and 1,660 females) from CLL will occur in the United States in 2023. Doctors cannot say for sure how long anyone will live with T-cell leukemia.

The rates of gene duplication in these model species are estimated at between 0.2% and 2% per gene per million years (5, 6).

While individual gene duplication is common, whole-genome duplications also are thought to have been a significant factor in vertebrate evolution, and the primary source of gene duplicates in plants (Wendel 2000).

Frequency. The prevalence of MECP2 duplication syndrome is unknown; more than 200 affected individuals have been described in the scientific literature. It is estimated that this condition is responsible for 1 to 2 percent of all cases of intellectual disability caused by changes in the X chromosome.

Research shows that several genes that control cell growth and division are located on chromosome 9. Many of these genes are tumor suppressors, which means they normally help prevent cells from growing and dividing in an uncontrolled way.

The term "duplication" simply means that a part of a chromosome is duplicated, or present in 2 copies. This results in having extra genetic material, even though the total number of chromosomes is usually normal.

How do you test for T-cell leukemia? ›

The diagnosis of T-cell leukemia begins with a blood test called a complete blood count (CBC). A CBC measures the numbers of different types of cells in the blood. If the blood contains many white blood cells, T-cell leukemia may be suspected.

T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL) are considered the same disease, differing by the extent of bone marrow infiltration.

CAR T-cell therapy is a promising treatment for patients with many types of blood cancer, including leukemia. It is a highly-specialized therapy that involves genetically modifying a patient's own T cells to attack their cancer. Learn more about CAR T-cell therapy.

According to the Leukemia and Lymphoma Society (LLS), the average 5-year survival rate for ALL, the most common type of leukemia in children, is 94.4 percent for those under age 5. There's a slight drop to 92.5 percent for older children under age 15.

Currently, standard treatment of T-ALL takes the form of long-term chemotherapy and drug intake to prevent or treat side effects associated with low white blood cell count as a result of intensive chemotherapy regimes. The treatment typically takes place over three stages: induction, consolidation, and maintenance.

Generally, staging is a way of describing where a cancer is located, if or where it has spread, and whether it is affecting other parts of the body. Unlike most solid tumors, there is no standard staging system for LGLL, T-PLL, ATLL, or Sezary syndrome.

We recommend T-ALL patients receive early intensified therapy, with a 4-drug induction containing dexamethasone and an anthracycline followed by aBFM-like consolidation containing cyclophosphamide.

Acute lymphoblastic leukaemia is a type of cancer that affects white blood cells. It progresses quickly and aggressively and requires immediate treatment. Both adults and children can be affected. Acute lymphoblastic leukaemia is rare, with around 790 people diagnosed with the condition each year in the UK.

Treatment approaches for T-ALL

Patients with newly diagnosed T-ALL are typically treated with risk-based multiagent chemotherapy regimens for 2 to 3 years, with or without cranial radiation therapy (CRT).

Who is most at risk for acute lymphoblastic leukemia? ›

Key facts. The human T-lymphotropic virus type 1 is also known by the acronym HTLV-1, or as human T-cell leukaemia virus type 1. The virus can cause a type of cancer called adult T-cell leukaemia/lymphoma (ATL). HTLV-1 is transmitted primarily through infected bodily fluids including blood, breast milk and semen.

The brain is the most commonly involved site (93%), followed by the spinal cord (4%) and the meninges (2%) (4).

The first symptoms in your child may be large swollen glands in the neck, chest, under the arms or in the groin. Swollen lymph glands in the neck and chest may cause a cough, shortness of breath, wheezing or swelling of the face. Some children may experience fevers, pale skin, rashes or decreased appetite.

Childhood lymphoblastic lymphoma is treated with the same treatment regimens that are used for acute lymphoblastic leukemia (ALL). The cure rate for both conditions is high.

T cell production by the thymus naturally wanes with age, but stress, toxic chemotherapy, radiation or infection can also torpedo thymic output. “But the thymus actually has this remarkable capacity to regenerate itself,” Dudakov said.

Chronic leukemia progresses more slowly and results in the accumulation of relatively mature, but still abnormal, white blood cells. It tends to take longer to start causing noticeable problems than acute leukemia. However, chronic, slower-growing leukemia may be more difficult to treat.

In general, leukemia occasionally can be caused by a genetic mutation or change. These may be genetic mutations passed from generation to generation within a family or from environmental factors, such as smoking or exposure to chemicals or radiation. However, most often the cause of leukemia is not known.

Patients with T-PLL often have genetic changes to their T-cells called a T-cell receptor rearrangement, which is linked to abnormal T-cell growth. This type of genetic change occurs from damage to the genes during a person's life. It is not passed from parent to child. Adult T-cell leukemia/lymphoma (ATLL).

The lifespan of a human memory T cell is of the order of 30–160 days [12,13,15,16], in contrast to the typical half-life of human T cell memory of 8–15 years [1,4,5]. Longevity thus does not seem to be an intrinsic characteristic of circulating memory T cells.

Is T-cell lymphoma terminal? ›

Most cutaneous T-cell lymphomas grow very slowly and aren't life-threatening, but some people may develop serious forms of the condition. Healthcare providers have treatments to ease symptoms, but they can't cure the lymphomas.

Angioimmunoblastic T-cell lymphoma

Angioimmunoblastic lymphoma (AITL) is a rare type of non-Hodgkin lymphoma (NHL). It is a high grade (aggressive) lymphoma that affects blood cells called T cells.

Human T-cell leukemia virus type 1 is spread by sharing syringes or needles, through blood transfusions or sexual contact, and from mother to child during birth or breast-feeding.

Though cutaneous T-cell lymphoma is chronic, it is treatable. Patients who enter remission should be monitored closely for returning symptoms.

People with the deletion without major physical or health problems are likely to have a normal life expectancy.

Chromosome 9q deletion is a chromosome abnormality that occurs when there is a missing (deleted) copy of genetic material on the long arm (q) of chromosome 9. The severity of the condition and the signs and symptoms depend on the size and location of the deletion and which genes are involved.

A rearrangement (translocation) of genetic material between chromosomes 9 and 22 causes a type of cancer of blood-forming cells called chronic myeloid leukemia. This slow-growing cancer leads to an overproduction of abnormal white blood cells.

The 9p deletion syndrome is characterized by trigonocephaly, moderate to severe mental retardation, low-set, malformed ears, and dysmorphic facial features, such as up-slanting palpebral fissures and a long philtrum [1, 2].

Those with velocardiofacial syndrome (VCFS) but without serious heart defects can expect a normal lifespan.

Is chromosome deletion a disability? ›

Chromosomal deletion syndromes result from loss of parts of chromosomes. They may cause severe congenital anomalies and significant intellectual and physical disability.

Other changes in the structure or number of copies of chromosome 9 can have a variety of effects. Intellectual disability, delayed development, distinctive facial features, and an unusual head shape are common features.

Kleefstra syndrome is caused by a mutation in a gene called EHMT1 or the deletion of a specific region of chromosome 9 that includes EHMT1. Other names for Kleefstra syndrome include 9q-syndrome, 9q34. 3 deletion syndrome, and chromosome 9q deletion syndrome.

The genetic size of chromosome 9 is ~140 Mb. It is ~4.5% of the total human genome. The length of the short arm is ~41 Mb; the length of the long arm is ~99 Mb. Chromosome 9 contains between 900 and 1,200 genes.

Maternal derivative chromosome 9 may cause recurrent pregnancy loss.

Wolf-Hirschhorn syndrome (WHS) is an extremely rare chromosomal disorder caused by a missing piece (partial deletion or monosomy) of the short arm of chromosome 4.

In most cases, Chromosome 9, Partial Monosomy 9p appears to result from spontaneous (de novo) errors very early in embryonic development that occur for unknown reasons (sporadically).

The Philadelphia chromosome forms when chromosome 9 and chromosome 22 break and exchange portions. This creates an abnormally small chromosome 22 and a new combination of instructions for your cells that can lead to the development of chronic myelogenous leukemia.